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doc.nr. 8 2 5 7300a.07 product family specification SCA3000 series 3-axi s accelerometer
SCA3000 series vti technologies oy 2/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 table of contents 1 general descr iption ........................................................................................................... 5 1.1 introduction ................................................................................................................................5 1.2 functional description ..............................................................................................................5 1.2.1 sensing element..................................................................................................................5 1.2.2 interface ic...........................................................................................................................5 1.2.3 factory calibration ..............................................................................................................6 1.2.4 supported features ............................................................................................................. 6 1.2.5 operation modes................................................................................................................ .6 1.2.5.1 measurement.................................................................................................................... ............6 1.2.5.2 motion dete ction............................................................................................................... ...........6 1.2.6 free-fall detection ..............................................................................................................6 1.2.7 interrupt................................................................................................................................7 1.2.8 temperature output ............................................................................................................7 1.2.9 output ring buffer................................................................................................................7 2 reset and power up, operation mod es, hw function s and cl ock ................................. 7 2.1 reset and power up...................................................................................................................7 2.2 measurement mode ............................................................................................................... ....7 2.2.1 description...........................................................................................................................7 2.2.1.1 bypass measureme nt mode.......................................................................................................8 2.2.1.2 narrow band measu rement mode..............................................................................................8 2.2.1.3 wide band measu rement mode .................................................................................................8 2.2.2 usage....................................................................................................................................8 2.2.2.1 overflow condition ............................................................................................................. .........8 2.3 motion detection mode .............................................................................................................9 2.3.1 description...........................................................................................................................9 2.3.2 usage.......................................................................................................................... ........10 2.3.3 examples....................................................................................................................... .....10 2.4 free-fall detection............................................................................................................ .......11 2.4.1 description.................................................................................................................... .....11 2.4.2 usage.......................................................................................................................... ........11 2.4.3 example........................................................................................................................ ......11 2.5 ring buffer ...............................................................................................................................12 2.5.1 description.................................................................................................................... .....12 2.5.2 usage.......................................................................................................................... ........12 2.5.2.1 overflow condition ............................................................................................................. .......12 2.5.3 examples....................................................................................................................... .....13 2.6 temperature measurement.....................................................................................................13 2.6.1 usage.......................................................................................................................... ........13 2.7 interrupt function (int-pin) ................................................................................................... ..13 2.7.1 usage.......................................................................................................................... ........13 2.8 clock .........................................................................................................................................14
SCA3000 series vti technologies oy 3/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 3 addressing space ............................................................................................................ 15 3.1 register description........................................................................................................... .....15 3.2 non-volatile memory ............................................................................................................ ...16 3.3 output registers............................................................................................................... .......16 3.4 configuration registers ........................................................................................................ ..19 4 serial in terfaces .............................................................................................................. .24 4.1 spi interface .............................................................................................................................24 4.1.1 spi frame format............................................................................................................... .24 4.1.2 spi bus error conditioning ...............................................................................................25 4.1.3 examples of spi communication.....................................................................................25 4.1.3.1 example of re gister read....................................................................................................... ....25 4.1.3.2 example of decremente d register read ...................................................................................26 4.1.3.3 example of ri ng buffer read .................................................................................................... ..26 4.2 i 2 c interface .................................................................................................................... ..........27 4.2.1 i 2 c frame format................................................................................................................. 27 4.2.1.1 i 2 c write mode ................................................................................................................... .........27 4.2.1.2 i 2 c read mode.................................................................................................................... .........27 4.2.1.3 decremented re gister read ...................................................................................................... .27 4.2.2 examples of i 2 c communication......................................................................................28 5 electrical char acteristi cs ................................................................................................ 29 5.1 absolute maximum ratings.....................................................................................................29 5.2 power supply ................................................................................................................... ........29 5.3 digital i/o specification...................................................................................................... .....29 5.3.1 digital i/o dc characteristics ...........................................................................................29 5.3.2 digital i/o level shifter...................................................................................................... .29 5.3.3 spi ac characteristics ......................................................................................................30 5.3.4 i 2 c ac characteristics .......................................................................................................31 6 package charact eristics.................................................................................................. 31 6.1 dimensions..................................................................................................................... ..........31 7 application in formation ................................................................................................... 32 7.1 pin description................................................................................................................ .........32 7.2 recommended circuit diagram ..............................................................................................32 7.3 recommended pwb layout ....................................................................................................33 7.4 assembly instructions .......................................................................................................... ..35 7.5 tape and reel specifications................................................................................................... 35 8 data sheet re feren ces ...................................................................................................... 36
SCA3000 series vti technologies oy 4/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 8.1 offset.........................................................................................................................................36 8.1.1 offset calibration error .....................................................................................................36 8.1.2 offset temperature error...................................................................................................36 8.2 sensitivity .................................................................................................................... .............37 8.2.1 sensitivity calibration error..............................................................................................37 8.2.2 sensitivity temperature error ...........................................................................................37 8.3 linearity ....................................................................................................................................38 8.4 noise .........................................................................................................................................39 8.5 bandwidth.................................................................................................................................39 8.6 cross-axis sensitivity ......................................................................................................... .....39 8.7 turn-on time ................................................................................................................... ..........40 9 order info rmation............................................................................................................. 4 1 10 document change control.............................................................................................. 42 11 contact info rmation ......................................................................................................... 43
s c a3000 series vti technologie s oy 5/ 43 www.vti.fi doc.nr. 825 730 0a.07 rev.a.07 1 general description 1.1 introduction sca300 0 is a thre e axis accele rom e te r family targe t ed for pro d u c ts req u irin g high p e rfo r m ance with low p o wer co nsumpti on. it consi s ts of a 3d -me m s sen s ing element an d a sign al co nd itioning asic packag ed into a pla s tic molded int e rconn ectio n device pa cka ge (mid). a block di ag ram of the SCA3000 p r od u c t family is prese n ted in fi gure 1 b e lo w. in t de - mu x 1: 3 low -pass filt er low -pass filt er low -pass filt er dec i mation dec i mation dec i mat i on coordinat e m a ppi n g and c a librat i on o scil l at or & cl oc k m o t i on det ect o r fr ee f a ll det ect o r ref e rence spi & i2 c i/ f c ont r o l & int sck / sc l mi so / s d a mo si csb ring bu ffe r c/ v an a l o g c a librat i on & ad c no n - vol a t ile me m o r y t e mper a t ure sensor figure 1. SCA3000 blo ck diag ram. this do cum e nt, no. 82 57 300, d e scri b e s th e p r od u c t spe c ificati on (e.g. op e r ation mode s, use r acce ssi ble re gisters, ele c trical prope rtie s and ap plica t ion inform ati on) for the s c a300 0 family. the spe c ification for an individ u a l sen s o r is a v ailable in the corre s po ndin g data sh eet. 1.2 functional description 1.2.1 sensing element the sen s ing element i s m anufa c ture d u s ing the pr op rietary bul k 3 d -mems p r o c e ss, whi c h e nable s robu st, stable and low n o ise & powe r ca pacitive sen s ors. the sensing element cons ists of three acceleration sensit ive masses. a c celeration will cause a cap a cita nce cha nge th at will be then conve r ted i n to a voltag e chang e in th e sig nal con d i t ioning asic. due to its me ch ani cal co nst r u c tio n , the ele m e n t's m e a s ure m ent coo r din a tes are rotat ed 45 comp ared to the co nventio nal orth o gon a l x,y,z coordi nate syste m . 1.2.2 interface ic the sen s in g eleme n t is interfa c ed via a capa citance - to-volt age (cv ) converte r. fol l owin g calib ration in the an alog domain, th e sign al is con v erted by a su ccessive a pproxim ation type of analo g -to - digi tal conve r ter (adc). th e adc' s signal is de -multiple x ed into thre e sign al processi n g cha nnel s wh ere it is low-pass filtered and deci m a t ed. after th at, the signa ls are ma pp ed into orthog onal co ordin a tes (x-y-z) an d tran sferred to the output regi sters. depe ndi ng on the pro duct, the sca30 0 0 se nsor su pport s eith er a fully digi tal se rial s p i or i 2 c in terface. in n o rmal measurement mode, a c cel e ration data can be rea d via the serial b u s. othe r sup ported fe atures a r e a se pa rate m o tion dete c tio n mod e an d parall e l fre e -f all dete c tion. in these mod e s, the sen s o r will gene rate an i n terrupt wh en a pre-define d con d ition h a s be en met. the sca3 00 0 inclu d e s a n intern al oscillator, re ference and no n-volatile me mory that en able th e sen s o r ' s auto nomou s o peration within a system. th e temperat ure sen s o r is use d in so me p r odu ct appli c ation s t o enh an ce th e tempe r atu r e stability. in that ca se, te mperature inf o rmatio n can also be read o u t from the device.
SCA3000 series vti technologies oy 6/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 1.2.3 factory calibration sensors are factory calibrated and the trimmed para meters are gain, offset and the frequency of the internal oscillator. calibrati on parameters will be read automat ically from the internal non- volatile memory during sensor startup. 1.2.4 supported features features supported by individual SCA3000 products are listed in table 1 below. table 1. SCA3000 devices? summary. features SCA3000-d01 (spi) / SCA3000-d02 (i2c) SCA3000-e01 (spi) / SCA3000-e02 (i2c) SCA3000-e04 SCA3000-e05 supply voltage 2.35 v ? 3.6 v 2.35 v ? 3.6 v 2.35 v ? 3.6 v 2.35 v ? 3.6 v i/o voltage 1.7 v ? 3.6 v 1.7 v ? 3.6 v 1.7 v ? 3.6 v 1.7 v ? 3.6 v measuring range 2 g 3 g 6 g 18 g resolution 0.75mg / 0.04 1mg / 0.06 2mg / 0.11 6.25mg / 0.36 sensitivity 1333 counts/g 1000 counts/g 500 counts/g 160 counts/g output buffer user enabled, 64 sampl./axis user enabled, 64 sampl./axis user enabled, 64 sampl./axis user enabled, 64 sampl./axis motion detection user enabled user enabled user enabled user enabled free fall detection user enabled user enabled user enabled user enabled interface spi max 1.6 mhz (-d01) / i 2 c fast mode (-d02) spi max 325 khz (-e01) / i 2 c std mode (-e02) spi max 325 khz spi max 325 khz temperatu re output yes no no no clock internal internal internal internal 1.2.5 operation modes 1.2.5.1 measurement the SCA3000 is in normal measurement mode by default after start up. the sensor offers acceleration information via the spi or i 2 c when the master requires it. the master can acquire one axis acceleration or all three axis accelera tion depending on the application. measurement resolution depends on the product type (see table 1). 1.2.5.2 motion detection motion detection (md) mode is intended to be used to save system level power consumption. in this mode, the SCA3000 activates the interrupt vi a the int-pin when motion is detected. sensitivity levels can be configured via the spi or i 2 c bus for each axis. moreover, the detection condition can be defined using sensitivity directions with and / or / mux logic. once the interrupt has happened, the detected direction can be read out fr om the corresponding status register. normal acceleration information is not available in md mode. 1.2.6 free-fall detection free-fall detection (ffd) is intended to be used to save system resources. this feature activates the interrupt via the int-pin when free-fall is detected. the minimum detectable distance depends on the individual product. normal acceleration information is available when the ffd is enabled.
SCA3000 series vti technologies oy 7/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 1.2.7 interrupt the SCA3000 has a dedicated output pin (int) to be us ed as the interrupt for the master controller. interrupt conditions can be activat ed and deactivated via the spi or i 2 c bus. once the interrupt has happened, the interrupt source can be read out from the corresponding status register. 1.2.8 temperature output some SCA3000 products provide 9-bit temperature in formation via the serial interface. see table 1 for detailed product information. 1.2.9 output ring buffer in those applications where real time acceleration information is not needed, the ring buffer memory can be used to buffer accele ration data. this will release c resources for other tasks or for example, to offer a power saving mode while SCA3000 samples acceleration data into its buffer memory. acceleration data is sampled at a constant sample rate by the sensor. the buffer is a fifo type (first in first out) where the ol dest data is shifted out first. it has separate read and write address pointers, so it can be read and written simultaneously. if the buffer overflows , the oldest data is lost and the new data replaces the oldest samples. ring buffer logic can be configured to give an in terrupt when the buffer is ? or ? full. the entire ring buffer content can be read by one read sequence. 2 reset and power up, operation modes, hw functions and clock 2.1 reset and power up the SCA3000 has an external active low reset pin. power supplies must be within the specified range before the reset can be released. after releasing the reset, the SCA3000 will read configuration and calibration data from the non- volatile memory to volatile registers. then th e SCA3000 will make a check sum calculation to the read memory content. the status register's csme-bit="0" shows successful memory read operation. 2.2 measurement mode 2.2.1 description the SCA3000 enters the measurement mode by def ault after power-on and the cv-converter will start to feed data to the signal channel (figure 1). data will be reliable in the output registers after the product specific turn-on time. the SCA3000 can also be set to optional me asurement modes. see component specific data sheets for detailed functional parameters in a ll measurement modes. all available measurement modes for the SCA3000 are described in table 2 below.
SCA3000 series vti technologies oy 8/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 table 2. available measurement modes for SCA3000. available measurement modes SCA3000-d01 SCA3000-d02 SCA3000-e01 SCA3000-e02 SCA3000-e04 SCA3000-e05 default after power-on or reset measurement mode measurement mode measurement mode measurement mode optional measurement mode 1 bypass measurement mode narrow band measurement mode narrow band measurement mode narrow band measurement mode optional measurement mode 2 not available not available wide band measurement mode wide band measurement mode 2.2.1.1 bypass measurement mode in bypass measurement mode, the signal bandwidth of the SCA3000 is extended by bypassing the low-pass filter in signal channel. as a result of a wider measurement bandwidth, the noise level is higher. 2.2.1.2 narrow band measurement mode in narrow band measurement mode, the signal bandwidth of the SCA3000 is reduced by increasing low-pass filtering in signal channel. in addition, t he output data rate is halved due to decimation. as a result of a narrower signal bandwidth, the noise level is lower. 2.2.1.3 wide band measurement mode in wide band measurement mode, the SCA3000 signal channel low-pass filtering pass band is widened. as a result of a wider measurement bandwidth, the noise level is higher. 2.2.2 usage the optional measurement modes can be enabled by setting the bits called mode_bits in mode register to "010" or "001". see sect ion 3.4 for mode register details. acceleration data can be read from data output regi sters x_lsb, x_msb, y_lsb, y_msb, z_lsb and z_msb in all measurement modes. each of these registers can be read one by one or using the decrement register read, which is descri bed in section 4.1.3.2 for spi and 4.2.1.3 for i 2 c interface. see section 3.3 for output register details. 2.2.2.1 overflow condition since acceleration data registers have no limiter, th e possible overflow needs to be detected using bits [b7, b6, b5]. if bits [b7, b6, b5] are ?011? or ?100?, data overflow has occurred (see table 3). this applies for all acceleration output registers (x_lsb ? z_msb and buf_data). table 3. overflow bit patterns in accelerati on data registers (x_lsb ? z_msb and buf_data). byte msb byte lsb byte bit number acceleration data bit b7 sign b6 d11 b5 d10 b4 d9 b3 d8 b2 d7 b1 d6 b0 d5 b7 d4 b6 d3 b5 d2 b4 d1 b3 d0 b2:b0 data overflow on positive acceleration 0 1 1 x x x x x x x x x x xxx data overflow on negative acceleration 1 0 0 x x x x x x x x x x xxx x = ignore in case of overflow, the output register value mu st be discarded. when an ov erflow is detected, the bit pattern ?0101 1111 1111 1xxx? is used for positive accelerations and ?1010 0000 0000 0xxx? for
s c a3000 series vti technologie s oy 9/ 43 www.vti.fi doc.nr. 825 730 0a.07 rev.a.07 negative a c celeratio n s u n t il a valid accele ration va lue is re ad. in table 4 the maximum and minimum acceleratio n regi ster val u e s th at are in m e a s uri ng ran ge (for regi ste r s x_lsb ? z_ msb) for sca300 0-d0x and sca 3000 -e0x are presented. table 4. maxi mum and min i mum value s in the sca30 00 mea s u r ing range. SCA3000-d0 1 SCA3000-d0 2 SCA3000-e01 SCA3000-e02 SCA3000-e04 SCA3000-e05 first positive acceleration valu e out of rang e [mg] dec bin - 3072 011 0 0 0 00 00 00 0x xx - 3072 011 0 0 000 00 00 0x xx - 3072 011 0 0 000 00 00 0x xx - 3072 011 0 0 000 00 00 0x xx max i mum positive acceleration valu e in range [mg] dec bin 2303.25 mg 3071 010 1 1 1 11 11 11 1x xx 3071 mg 3071 010 1 1 111 11 11 1x xx 6142 mg 3071 010 1 1 111 11 11 1x xx 19193.75 mg 3071 010 1 1 111 11 11 1x xx minimum negative acceleration valu e in range [mg] dec bin -2304 mg -3072 101 0 0 0 00 00 00 0x xx -3072 mg -3072 101 0 0 000 00 00 0x xx -6144 mg -3072 101 0 0 000 00 00 0x xx -19200 mg -3072 101 0 0 000 00 00 0x xx first negative acceleration valu e out of rang e [mg] dec bin - -3073 100 1 1 1 11 11 11 1x xx - -3073 100 1 1 111 11 11 1x xx - -3073 100 1 1 111 11 11 1x xx - -3073 100 1 1 111 11 11 1x xx 2.3 motion de tection mode 2.3.1 description in md mod e , the a d c's d a ta is not fed to the si gnal processing chann el sho w n in figu re 1 but to the md blo c k. it consi s ts of a digital b and-pa ss f ilte r (bpf), th re shol d level p r ogra mmabl e digital comp arator a nd a co nfigurable trigg e r fu nction. bpf's -3 db low-pa ss freque ncy i s 25 hz ?60 hz an d -3 db high-p a ss frequ en cy is 0.05 hz ?1 hz. see fig u re 2 belo w . b a n d p ass f i l t e r ' s r e sp o n se fo r r e fe r e n c e o n l y -2 0 -1 5 -1 0 -5 0 5 0. 01 0. 1 1 10 100 1000 fr e q [ h z ] a tte n u a t i o n [d b ] lo w e r li m i t up p e r l i m i t figure 2. the md band -p a ss filter' s fre q uen cy respon se.
s c a3000 series vti technologie s oy 10/ 43 www.vti.fi doc.nr. 825 730 0a.07 rev.a.07 the ab solute value of pro g ramm able t h re shol d lev el (tl ) is 0 < |tl| < fs g (fs is sen s o r full scale mea s u r ing ran g e ) . note: due to powe r co n s umption opti m ization, the step si ze be tween each step a n d axis is not the sam e , see sectio n 3.4 for thre sh old l e vel details. the trigg e rin g con d ition can be defin ed using o r /and logi c: 1. any sensi ng dire ction can be co nfigured to trigger the interru pt (o r conditio n ). 2. any sensi ng dire ction can be co nfigured to be requi re d to trigger th e interrupt (a nd con d ition). +t l acce lerat i o n ex ceeds t he thr e sh o l d lev e l d ue to mo t i on -tl a c c e l e ra ti on x, y o r z t1 t2 t 3 t4 t5 t6 t7 t8 ti m e t1 t2 t 3 t4 t5 t6 t7 t8 ti m e in t outpu t "1" "0" figure 3. motion dete c tor o peratio n. 2.3.2 usage the m d mo d e ca n b e en a b led by settin g the m o de bits in th e m o de regi ster to "011". the trigge r con d ition ca n be defined by setting req_z, req_ y, req_x, en_z, en_y and en_x bits in md_ c t r l registe r an d z_th, y_t h and z_t h bits in md_z _th, m d _y_ t h an d md_x_t h regi sters, re spectively. se e sectio n 3. 4 for the co nfiguratio n re gister an d section 2.7 fo r the interrupt funct i onality details. in md mode , accel e ratio n data is n o t availabl e in regis t ers x_lsb, x_msb , y_lsb, y_ msb, z_lsb, z_m sb and buf_ data. 2.3.3 examples a simple exa m ple of motio n detectio n u s ag e: 1. write "00 0 0 0011" (0 3h ) into the mode re gister (en able motion dete c tion mod e , mode_bits = '011 '). 2. accel e ration data is not av ailable when t he sca30 00 is in motion d e tection mo d e . 3. the int-pin is activated whe n motion is detected, see se ction 2.7 for detailed int-pin information. in the next ex ample, the m o tion dete c to r is config ure d to give a n int e rrupt on mot i on only i n th e x- or y-axi s direction: 1. write "0 000 0011" (03 h ) into mode regi ster (ena ble m o tion dete c tio n mode , mode_bits = '011 ') 2. write "00 000 000" (0 0h) int o unlo ck registe r 3. write "01 010 000" (5 0h) int o unlo ck registe r 4. write "10 100 000" (a0h ) int o unlo ck registe r 5. write "00 000 010" (0 2h) int o ctrl_sel regi ste r (to select indi re ct md_ c t r l re gister) unlo ck se que nce for regi st er lock 6. write "00 000 011" (0 3h) i n to ctrl_ d ata r egiste r (this data i s written into md_ctrl regi ster, en ab le trigge r on y-ch ann el, en_y = '1 ', en able trigg e r o n x-ch ann el, en_x = '1' )
s c a3000 series vti technologie s oy 11/ 43 www.vti.fi doc.nr. 825 730 0a.07 rev.a.07 7. accel e ration data is not av ailable when t he sca30 00 is in motion d e tection mo d e 8. the int - pin is activated whe n motion is det ecte d in the x- or y-axis directi on (z -axis dire ction is ig nore d ), see section 2. 7 for detailed int - pin inform atio n. 2.4 free-fall detection 2.4.1 description duri ng f r ee -fa ll in the gravitation field, all 3 o r t hog onal accel e ratio n comp one nts are i deally eq ual to zero. due to pra c tical no n-idealitie s, det ection mu st be do ne usi n g th reshold level (t l) greater than 0. when enabled, the free-f all dete ction (ff d ) will monitor 8 msb's of the measured accel e ration in the x, y and z dire ction s . if the measu r ed a c cele rati on stay s with in the tl lo n ger tha n time tff (figu r e 4 be low), whi c h corre s p ond s approx 25 cm dro p dista n ce, the f f d will g ene rate an interrupt to the int-pi n. t1 t2 t 3 t4 t5 t6 t7 t8 +t l tff -tl a c c e l e ra ti on x , y and z ti m e t1 t2 t 3 t4 t5 t6 t7 t8 ti m e in t outpu t "1" "0" figure 4. fre e fall con d ition. 2.4.2 usage free -fall d e te ction ca n be enabl ed by setting ff d_e n bit in mo de regi ster to "1". see secti on 3.4 for mode regis t er details . accel e ration data is avail a ble in registe r s x_ l sb, x_msb, y_lsb, y_msb, z _lsb, z_msb and buf_ data as in m e a s u r eme n t mode . see se ctio n 3.3 for out put regi ster and sectio n 2.7 for interrupt funct i onality details. 2.4.3 example a simple exa m ple of free-f a ll detectio n usa ge: 1. write "00 010 000" (1 0h) int o the mode regi ste r (e nabl e free fall detection, ff d_ en = '1' ) 2. accel e ration data ca n be read no rmally 3. int-pi n is a c tivated whe n free fall is det ected, see se ction 2 . 7 for detailed int-pi n information.
SCA3000 series vti technologies oy 12/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 2.5 ring buffer 2.5.1 description the SCA3000's ring buffer is a 192 acceleration data samples long (64 samples of 11 bit three axis data) internal memory to relax the real-time operation requirements of the host processor. the following parameters are configurable: 1. each measurement axis can be individually disabled. if measurement data from e.g. y-axis is not needed, available memory can be used for x- and z-axis data. 2. buffer data length can be changed from 11 to 8 bits. in 8-bit mode , data can be read out using shorter read sequence. 3. ring buffer's input sample rate can be the same as the sensor's data rate or divided by 2 or 4. when the divider is e.g. 2, only every 2 nd acceleration data will be stored. 4. the interrupt condition, when enabled, can be selected between two: interrupt in int-pin occurs when the buffer is 50% or 75% full. 2.5.2 usage the ring buffer can be enabled by setting buf_en bit in mode register to "1". after enabling the buffer, acceleration data can be read from buf_da ta register using decrement register read, which is described in section 4.1.3.2 for spi and 4.2.1.3 for i 2 c interface. each measurement axis can be individually di sabled by setting corresponding bits in buf_x_en, buf_y_en and buf_z_en in ou t_ctrl register to "0". output data length can be changed from 11 bits to 8 bits by setting bit buf_8bit in mode register to "1". see section 3.3 for bit level descriptions. the count of available data samples in output ri ng buffer can be read from buf_count register. register value is updated only when it is accessed over the spi or i 2 c. data shift out order is x,y,z. in 11 bit mode two bytes must be read to get all 11 bits out. in that case, the msb byte is 1 st . examples: 1. 11 bits data length, x&y&z axis enabled: x1_msb, x1_lsb, y1_msb, y1_lsb, z1_msb, z1_lsb, x2_msb, x2_lsb, ... latest z_lsb 2. 11 bits data length, y&z axis enabled: y1_msb, y1_lsb, z1_msb, z1_lsb, y2_msb, y2_lsb, z2_msb, z2_lsb, y3_msb, y3_lsb, ..., latest z_lsb 3. 8 bits data length, all axis enabled: x1, y1, z1, x2, y2, z2,..., latest z 4. 8 bits data length, x&z axis enabled: x1, z1, x2, z2, x3, z3, ..., latest z 5. 8 bits data length, z axis enabled: z1, z2, z3, ... , latest z see section 2.7 for interrupt functionality details. acceleration data is available in x_lsb, x_msb, y_lsb, y_msb, z_lsb and z_msb when the ring buffer is enabled. 2.5.2.1 overflow condition overflow is detected from data ring buffer in same way as from the output registers. see section 2.2.2.1 for details.
s c a3000 series vti technologie s oy 13/ 43 www.vti.fi doc.nr. 825 730 0a.07 rev.a.07 2.5.3 examples a simple exa m ple of outpu t ring buffer u s ag e: 1. write "10 000 000" (c0h ) into mode regi ster (ena ble o u tput ring buff e r, buf_e n = '1' ) 2. accel e ration data ca n be read no rmally 3. int-pin is ac tivated when buffer is ? full, see sectio n 2.7 for detaile d int-pi n info rmation. in the n e xt e x ample , the output ring buffer is conf igure d to sample only the z-axis acceleration data with 8 b i t re solution and red u ced data rate (on l y every seco nd sampl e i s sto r ed into output ring b u ffer). i n addition , th e sca300 0 i s configu r ed t o give an inte rru pt whe n th e output rin g buffer is ? full: 1. write "110 00 000" (c0h) in to the m o de regi ste r (ena ble o u tput ri n g buffe r, buf _ en = ' 1', set data len g th to 8 bits, buf_8bit = '1' ) 2. write "00 000 000" (0 0h) int o unlo ck registe r 3. write "01 010 000" (5 0h) int o unlo ck registe r 4. write "10 100 000" (a0h ) int o unlo ck registe r 5. write "00 001 011" (0bh ) int o ctrl_sel regist e r (to select indi re ct out _ ct rl registe r) unlo ck se que nce for regi st er lock 6. write "0 000 0 101" (03h ) in to ct rl_ d a t a regi ster (this data i s written into out _ ct rl regi ster, sto r e z-axis data, buf_z _ en = '1', divide data rate by 2, buf_ rate = ' 01') 7. write " 10000001" (81h) i n to int_mask regi ster (set buffe r i n terrupt level to ? full, buf_f _ en = '1', set int-pi n to active high, int_act = '1' ) 8. accel e ration data ca n be read no rmally for all axis an d with full re solution. the buffer data can b e rea d from buf _ da ta regi ster 9. int-pi n is act i vated wh en t he outp u t rin g buffe r i s ? full of z-axis accele ration data, se e se ction 2.7 fo r detailed int - pin info rmati on. 2.6 temperature measurement 2.6.1 usage nine bit tem peratu r e info rmation is av ailable in the temp_msb and temp_lsb registe r s, if th e feature i s e n abled i n the prod uct (see table 1). th e temp_msb regi ster mu st be re ad b e fore th e temp_lsb registe r in ord e r to g e t valid tempe r at u r e data. regi sters are upd a t ed with the l a test temperature data wh en a c ce ssed. see se ction 3.3 fo r regi ster d e tails. the tempe r at ure registe r s? typical output at +23 c is 256 count s a nd a 1 c cha nge in tempe r ature typically corresp ond s to a 1.8 lsb chang e in the SCA3000 tempe r ature output. tem peratu r e information is c onverted to [c] as follows equation 1 [] c lsb lsb temp c c temp dec ? + = whe r e temp[ c ] is tempe r ature i n cel s i u s and temp de c is the tem peratu r e fro m temp_ms b and temp_lsb registe r s in d e c imal form at. 2.7 interrupt function (int-pin) 2.7.1 usage the motio n dete ctor a n d free fall dete ctor will gene rate a n interrupt t o int-pin when the corre s p ondin g functio n is enabl ed an d the interru p t condition i s m e t. the sca3 000' s ri ng buf fer wil l gene rate an interrupt wh e n interrupt function a lity has bee n ena b l ed. setting buf_f _ en bit in int_mask regis t er "1" res u lts in interrupt when the regis t er is 75 % full. setting buf_h_e n bit in int_mask regis t er "1" res u lts in interr upt when the regis t er is 50% full. setting int_all bit in int_mask regi st er will mask all interrupts.
SCA3000 series vti technologies oy 14/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 the interrupt polarity (active hi gh/low) can be configured with in t_mask register's int_act bit. once the interrupt has happened, the int_status register must be read to acknowledge the interrupt. 1. if at least one of md bits in int_status register is "1", motion has been detected. 2. if ffd bit in int_status register is "1", free-fall has been detected. 3. if buf_full bit is "1", ring buffer is 75% fu ll. correspondingly, if buf_half is "1", the ring buffer is 50% full. see section 3.3 for int_status register details. 2.8 clock the SCA3000 has an internal factory trimmed osc illator and clock generator. internal frequencies vary product by product.
SCA3000 series vti technologies oy 15/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 3 addressing space the SCA3000 register contents and bit definitions are described in more detail in the following sections. 3.1 register description the SCA3000 addressing space is presented in table 5 below. table 5. list of registers. addr. name description mode (r, w, rw, ia) reg. type locked 00h revid asic revision id number r conf 01h reserved - 02h status status register r conf 03h reserved - 04h x_lsb x-axis lsb frame r output 05h x_msb x-axis msb frame r output 06h y_lsb y-axis lsb frame r output 07h y_msb y-axis msb frame r output 08h z_lsb z-axis lsb frame r output 09h z_msb z-axis msb frame r output 0ah ... 0eh reserved - 0fh buf_data ring buffer output register r output 10h ... 11h reserved - 12h temp_lsb temperature lsb frame r output 13h temp_msb temperature msb frame r output 14h mode operating mode selection, control and configuration for: - mode selection - output buffer - free-fall detection rw conf 15h buf_count count of unread data samples in output buffer r output 16h int_status interrupt status register: - output buffer is not full, ? full or ? full - free-fall detected / not detected - information of which axis triggered motion r output 17h i2c_rd_sel register address for i 2 c read operation rw conf 18h ctrl_sel register address pointer for indirect control registers rw conf x 19h ... 1dh reserved - 1eh unlock unlock register rw conf 1fh ... 20h reserved -
SCA3000 series vti technologies oy 16/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 addr. name description mode (r, w, rw, ia) reg. type locked 21h int_mask hw interrupt mask register (configures the operation of int-pin): - interrupt when output buffer is ? full (enable / disable) - interrupt when output buffer is ? full (enable / disable) - mask all interrupts on int-pin (enable / disable) - int-pin activity (int active low / int active high) rw, nv conf 22h ctrl_data data to/from register which address is in ctrl_sel (18h) register rw, nv, ia conf x 23h ... 3fh reserved - add. is the register address in hex format. rw ? read / write register, r ? read-only register, nv ? register mirrors nv-memory data (nv = non-volatile). ia ? indirect addressing used. registers whose read and write access is blocked by register lock is marked in "locked" column. 3.2 non-volatile memory the SCA3000 has an internal non-volatile memory for calibration and configuration data. memory content will be programmed during production and is not user configurable. in itial configuration values can be found in the following section 3.4. 3.3 output registers the SCA3000 output registers (marked with 'output' in table 5) contents and bit definitions are described in this section. output registers c ontain information of measured acceleration and temperature as well as information of t he operating state and interrupts of SCA3000. when reading the output values an msb register must be read first because msb register reading latches the data in to all other acceleration output registers address: 04h register name: x_lsb , x-axis lsb frame bits mode initial value name description 7:0 r 00h data x-axis lsb frame address: 05h register name: x_msb , x-axis msb frame bits mode initial value name description 7:0 r 00h data x-axis msb frame address: 06h register name: y_lsb , y-axis lsb frame bits mode initial value name description 7:0 r 00h data y-axis lsb frame
SCA3000 series vti technologies oy 17/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 address: 07h register name: y_msb , y-axis msb frame bits mode initial value name description 7:0 r 00h data y-axis msb frame address: 08h register name: z_lsb , z-axis lsb frame bits mode initial value name description 7:0 r 00h data z-axis lsb frame address: 09h register name: z_msb , z-axis msb frame bits mode initial value name description 7:0 r 00h data z-axis msb frame address: 0fh register name: buf_data , ring buffer output register bits mode initial value name description 7:0 r 00h data ring buffe r output register bit level description for acceleration data fr om x_lsb ... z_msb and buf_data registers is presented in table 6 ... table 9. acceleration data is presented in 2's complement format. at 0 g acceleration the output is ideally 00h. table 6. bit level description for accelera tion registers of SCA3000-d01 and SCA3000-d02. byte msb byte lsb byte bit number acceleration [mg] b7 sign b6 1536 b5 768 b4 384 b3 192 b2 96 b1 48 b0 24 b7 12 b6 6 b5 3 b4 1.5 b3 0.75 b2:b0 xxx SCA3000-d01,-d02 [x_lsb?z_msb] s d11 d10 d9 d8 d7 d6 d5 d4 d3 d2 d1 d0 xxx SCA3000-d01,-d02 ring buffer in 11-bit mode [buf_data] s d9 d8 d7 d6 d5 d4 d3 d2 d1 d0 x x xxx SCA3000-d01,-d02 ring buffer in 8-bit mode [buf_data] s d6 d5 d4 d3 d2 d1 d0 x x x x x xxx s = sign bit x = not used bit table 7. bit level description for accelera tion registers of SCA3000-e01 and SCA3000-e02. byte msb byte lsb byte bit number acceleration [mg] b7 sign b6 2048 b5 1024 b4 512 b3 256 b2 128 b1 64 b0 32 b7 16 b6 8 b5 4 b4 2 b3 1 b2:b0 xxx SCA3000-e01,-e02 [x_lsb?z_msb] s d11 d10 d9 d8 d7 d6 d5 d4 d3 d2 d1 d0 xxx SCA3000-e01,-e02 ring buffer in 11-bit mode [buf_data] s d9 d8 d7 d6 d5 d4 d3 d2 d1 d0 x x xxx SCA3000-e01,-e02 ring buffer in 8-bit mode [buf_data] s d6 d5 d4 d3 d2 d1 d0 x x x x x xxx s = sign bit x = not used bit
SCA3000 series vti technologies oy 18/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 table 8. bit level description for ac celeration registers of SCA3000-e04. byte msb byte lsb byte bit number acceleration [mg] b7 sign b6 4096 b5 2048 b4 1024 b3 512 b2 256 b1 128 b0 64 b7 32 b6 16 b5 8 b4 4 b3 2 b2:b0 xxx SCA3000-e04 [x_lsb?z_msb] s d11 d10 d9 d8 d7 d6 d5 d4 d3 d2 d1 d0 xxx SCA3000-e04 ring buffer in 11-bit mode [buf_data] s d9 d8 d7 d6 d5 d4 d3 d2 d1 d0 x x xxx SCA3000-e04 ring buffer in 8-bit mode [buf_data] s d6 d5 d4 d3 d2 d1 d0 x x x x x xxx s = sign bit x = not used bit table 9. bit level description for ac celeration registers of SCA3000-e05. byte msb byte lsb byte bit number acceleration [mg] b7 sign b6 12800 b5 6400 b4 3200 b3 1600 b2 800 b1 400 b0 200 b7 100 b6 50 b5 25 b4 12.5 b3 6.25 b2:b0 xxx SCA3000-e05 [x_lsb?z_msb] s d11 d10 d9 d8 d7 d6 d5 d4 d3 d2 d1 d0 xxx SCA3000-e05 ring buffer in 11-bit mode [buf_data] s d9 d8 d7 d6 d5 d4 d3 d2 d1 d0 x x xxx SCA3000-e05 ring buffer in 8-bit mode [buf_data] s d6 d5 d4 d3 d2 d1 d0 x x x x x xxx s = sign bit x = not used bit address: 12h register name: temp_lsb , temperature lsb frame bits mode initial value name description 7:0 r 00h temp temperature lsb frame address: 13h register name: temp_msb , temperature msb frame bits mode initial value name description 7:0 r 00h temp temperature msb frame the bit level description for temperature data from temp_msb and temp_lsb registers is presented in table 10. temperature data is presented in unsigned format. the lsb bit (bit b5 or t0 in table 10) weight is ~0.56c. see section 2.6 fo r more detailed information of converting the data to temperature in [c]. table 10. bit level description for temper ature registers [temp_msb ? temp_lsb]. register temp_msb temp_lsb bit number b7:b6 b5 b4 b3 b2 b1 b0 b7 b6 b5 b4:b0 bit in temperature register xx t8 t7 t6 t5 t4 t3 t2 t1 t0 xxxxx x = not used bit
SCA3000 series vti technologies oy 19/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 address: 15h register name : buf_count , output ring buffer status bits mode initial value name description 7:0 r 00h count count of available data samples in output ring buffer, for more information see section 2.5.2. address: 16h register name: int_status , interrupt status register (all interr upts that are available in current operation mode) bits mode initial value name description 7 r 0 buf_full output ring buffer is ? full 1 ? ring buffer is ? full 0 ? ring buffer is not full 6 r 0 buf_half output ring buffer is ? full 1 ? ring buffer is ? full 0 ? ring buffer is not full 5:4 reserved 3 r 0 ffd free-fall detection 1 ? free-fall detected (0 g acceleration) 0 ? free-fall not detected 2:0 r 000 md motion detector triggered channel indication 1xx ? trigger on y-axis x1x ? trigger on x-axis xx1 ? trigger on z-axis 3.4 configuration registers SCA3000 configuration register (m arked with 'conf' in table 5) contents and bit definitions are described in this section. confi guration registers are used to co nfigure SCA3000 operation and the operation parameters. address: 00h register name: revid , asic revision id number tied in metal bits mode initial value name description 7:4 r 2h revmaj major revision number 3:0 r 1h revmin minor revision number address: 02h register name: status , status register bits mode initial value name description 7:6 reserved 5 r 0 lock status of lock register 0 ? lock is closed 1 ? lock is open 4:2 reserved 1 r 0 csme eeprom checksum error 1 ? eeprom checksum error 0 ? no error 0 r 0 spi_frame spi frame error. bit is reset, when next correct spi frame is received (only for products with spi bus). 1 ? spi frame error 0 ? no error
SCA3000 series vti technologies oy 20/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 address: 14h register name: mode , operation mode selection bits mode initial value name description 7 rw 0 buf_en output ring buffer 1 ? enabled 0 ? disabled (buffer in power down) 6 rw 0 buf_8bit output ring buffer data length 1 ? ring buffer is read in single 8 bit frame per stored axis (8 bit mode) 0 ? ring buffer is read in two 8 bit frames per stored axis (11 bit mode). unused bits are set to 0. 5 reserved 4 rw 0 ffd_en free-fall detection 1 ? enabled 0 ? disabled (detection in power down) 3 reserved 2:0 rw 000 mode_bits selects SCA3000 series operation mode 000 ? normal measurement mode 010 ? optional measurement mode 1 (see table 2) 001 ? optional measurement mode 2 (see table 2) 011 ? md, motion detector other combinations are reserved address: 17h register name: i2c_rd_sel , register address for i 2 c read operation bits mode initial value name description 7:0 w 00h addr address of register to be read via i 2 c. register is used only for i 2 c read access. address: 18h register name: ctrl_sel , control register selector, unlock required bits mode initial value name description 7:5 rw 000 reserved 4:0 rw 00000 select indirect control registers, select register address for read / write access: 00001 ? i2c_disable 00010 ? md_ctrl (motion detector control) 00011 ? md_y_th (motion detector y- threshold) 00100 ? md_x_th (motion detector x- threshold) 00101 ? md_z_th (motion detector z- threshold) 01011 ? out_ctrl (output control) other combinations are reserved ctrl_sel register works as an address pointer for registers listed below. when this register is written the content of selected register is avail able for reading/writing from/to register ctrl_data.
SCA3000 series vti technologies oy 21/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 address value: 00010 register name: md_ctrl , motion detector control (indirect access via ctrl_sel) bits initial value name description note 7:6 reserved 5 0 req_z 1 ? require trigger on z-channel 0 ? not required 4 0 req_x 1 ? require trigger on x-channel 0 ? not required 3 0 req_y 1 ? require trigger on y-channel 0 ? not required bits 5:3 can be used to build logical and operation between channels. example: x and y = require x and y, ignore z 00 011 011 2 1 en_z 1 ? enable trigger on z-channel 0 ? not required 1 1 en_x 1 ? enable trigger on x-channel 0 ? not required 0 1 en_y 1 ? enable trigger on y-channel 0 ? not required bits 2:0 can be used to build logical or operation between channels. example: x or y = disable z 00 000 011 address value: 00011 register name: md_y_th , motion detector y-threshold (indirect access via ctrl_sel) bits initial value name description 7:0 10h or 08h y_th threshold for y-acceleration change when md is used. address value: 00100 register name: md_x_th , motion detector x-threshold (indirect access via ctrl_sel) bits initial value name description 7:0 10h or 08h x_th threshold for x-acceleration change when md is used. address value: 00101 register name: md_z_th , motion detector z-threshold (indirect access via ctrl_sel) bits initial value name description 7:0 10h or 08h z_th threshold for z-acceleration change when md is used. initial values for registers md_x_th, md_y_t h and md_z_th vary with SCA3000 product types. initial value is: ? 10h for SCA3000-d01, SCA3000-d02, SCA3000-e01 and SCA3000-e02 ? 08h for SCA3000-e04 and SCA3000-e05 the bit level descriptions for registers md_x _th, md_y_th and md_z_th are presented in, table 11 ...table 14 below. the threshold levels ar e in unsigned format and they are absolute values for the acceleration that triggers the mo tion detector interrupt. values presented below are typical threshold values and they are not factory calibrated.
SCA3000 series vti technologies oy 22/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 table 11. bit level description for motion detec tor typical threshold levels (SCA3000-d01 and SCA3000-d02). typical bit weights bit number b7 b6 b5 b4 b3 b2 b1 b0 SCA3000-d01, -d02 acceleration [mg] md_x_th, md_th_z x x 1300 650 350 200 100 50 SCA3000-d01, -d02 acceleration [mg] md_y_th x 1750 850 450 250 150 100 50 x = not used bit table 12. bit level description for motion detector typical threshold levels (SCA3000-e01 and SCA3000-e02). typical bit weights bit number b7 b6 b5 b4 b3 b2 b1 b0 SCA3000-e01, -e02 acceleration [mg] md_x_th, md_th_z x x 2050 1050 550 300 150 100 SCA3000-e01, -e02 acceleration [mg] md_y_th x 2700 1350 700 350 200 100 50 x = not used bit table 13. bit level description for motion detector typical threshold levels (SCA3000-e04). typical bit weights bit number b7 b6 b5 b4 b3 b2 b1 b0 SCA3000-e04 acceleration [mg] md_x_th, md_th_z x x 4100 2100 1100 600 300 200 SCA3000-e04 acceleration [mg] md_y_th x 5400 2700 1400 700 400 200 100 x = not used bit table 14. bit level description for motion detector typical threshold levels (SCA3000-e05). typical bit weights bit number b7 b6 b5 b4 b3 b2 b1 b0 SCA3000-e05 acceleration [mg] md_x_th, md_th_z x x 11900 6100 3200 1700 900 600 SCA3000-e05 acceleration [mg] md_y_th x 15600 7800 4100 2000 1200 600 300 x = not used bit
SCA3000 series vti technologies oy 23/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 address value: 01011 register name: out_ctrl , output configuration (indirect access via ctrl_sel) bits initial value name description 7:5 reserved 4 1 buf_x_en store x-axis acceleration data to ring buffer 1 ? enabled 0 ? disabled 3 1 buf_y_en store y-axis acceleration data to ring buffer 1 ? enabled 0 ? disabled 2 1 buf_z_en store z-axis acceleration data to ring buffer 1 ? enabled 0 ? disabled 1:0 00 buf_rate additional data rate reduction after calibration before data is loaded to ring buffer (no effect on output registers data rate , see section 2.5.1) 11 ? no rate reduction 10 ? divide rate by 4 01 ? divide rate by 2 00 ? no rate reduction address: 1eh register name: unlock , unlock register lock bits mode initial value name description 7:0 rw 00h key lock can be opened by writing the following sequence into this register: 00h, 50h, a0h writing any other sequence closes the lock. lock state can be read from status register. address: 21h register name: int_mask , hw interrupt mask register config ures the operation of the int pin. bits mode initial value name description 7 rw 0 buf_f_en interrupt when output ring buffer is ? full 1 ? enabled 0 ? disabled 6 rw 1 buf_h_en interrupt when output ring buffer is ? full 1 ? enabled 0 ? disabled 5:2 reserved 1 rw 0 int_all mask all interrupts (only effects on the int-pin) 1 ? mask all interrupts (including free fall detection and motion detector) 0 ? mask interrupts according to configured mode 0 rw 1 int_act int-pin signal activity 1 ? int active high (int-pin high) 0 ? int active low (int-pin low) address: 22h register name: ctrl_data , control register data, unlock required bits mode initial value name description 7:0 rw 00h data data bits [7:0] of selected 8-bit control register. write this register to actually perform the write operation to selected location. see register ctrl_sel for information on register contents.
s c a3000 series vti technologie s oy 24/ 43 www.vti.fi doc.nr. 825 730 0a.07 rev.a.07 4 serial interfaces comm uni cati on b e twe en the sca3 00 0 sen s or an d ma ster co ntrolle r i s b a s ed on seria l data transfe r a nd a dedi cate d interrupt line (int-pi n ). t w o different seri al interfa c e s are avail able for the sca300 0 se nso r : spi and i 2 c (phillips specifi c atio n v2.1). however, onl y one per product is enabl ed by pre-p r og rammi ng in the fact ory. the sc a 3000 a c ts a s a slave on b o th the spi an d i 2 c bus. 4.1 spi interface spi bus i s a full duplex synch r on ou s 4 - wire serial i n terface. it con s ist s of o ne maste r devi c e an d one or m o re slave device s . the m a ste r i s d e fined as a micro co ntroller providi n g the spi cl o ck, and the slave as any integ r ate d ci rcuit re cei v ing t he spi clo ck f r om th e ma ster. th e sca30 00 sensor alway s op era t es a s a slav e device in maste r -s lave ope ration m ode. a typica l spi conn ection i s pre s ente d in figure 5. dat a out (m os i) dat a i n ( m is o) se r i a l c l o c k ( s c k ) ss 0 ss 1 ss 2 ss 3 mas t e r m i cr ocontrol ler si so sc k cs sl a v e si so sc k cs si so sc k cs si so sc k cs figure 5. typical spi conn ection. the data tra n s fer u s e s the followin g 4-wi re interfa c e: mosi maste r out sl ave in c SCA3000 miso maste r in sla v e out sca300 0 c sck s e rial c l ock c SCA3000 cs b chip sele ct (lo w act i v e ) c SCA3000 4.1.1 spi frame format sca300 0 spi frame forma t and tran sfer protocol is p r ese n ted in fi gure 6. figure 6. spi frame form at. each comm u n icatio n fram e co ntain s 1 6 bits. the fi rst 8 bits i n m o si line co ntains i n fo abo ut the operation (re ad/write ) a n d the re giste r address bein g acce ssed. the first 6 bi ts define the 6 bit
s c a3000 series vti technologie s oy 25/ 43 www.vti.fi doc.nr. 825 730 0a.07 rev.a.07 address fo r t he sele cted operation, which is defin ed by bit 7 (?0? = re ad ? 1 ? = write), wh ich i s followe d by one ze ro bit. the later 8 bits in the mo si line co ntain d a ta for a write operatio n an d are ?don?t-ca re? fo r a re ad op eration. bits fro m mosi line are sampl ed i n on the ri sin g edge of sck and bits to miso line are lat c he d out on fallin g edge of sck. the first bits i n the miso li ne are the fra m e erro r bit (spi_frame, bit 2) of the previou s spi frame and o dd pa rit y bit (par, bit 8). parity is cal c ulate d fro m data which is currently sent. bit 7 is al ways ?1?. the l a ter 8 bits contain data fo r a re ad o peration. du ring the write op eration, these d a ta bi ts a r e previou s data bits of the addre s sed regi ster. for write co mmand s, dat a is written i n to the add re ssed re giste r on the risi ng edge of csb. if the comm and fra m e is invalid as de scri be d in the se ct ion data will not be writte n into the re gister (plea s e see " e rror conditio n ing" in se cti on 4.1.2). for rea d com m and s, data is latched int o the inte r nal spi output registe r (s hift regi ster) o n the 8t h risin g edg e of sck. the ou tput registe r i s shifted o u t msb first over miso outpu t. whe n the cs b is high stat e betwe en da ta transfe rs, the miso line is in the high -impeda nce st ate. 4.1.2 spi bus error conditioning while sen d in g an spi frame, if the csb is rai s ed to 1 - before sen d in g 16 scks o r - the numbe r o f sck pulse s is not divisibl e by 8, the frame error is a c tivated and the frame is con s id ered invali d . the status bit status.spi_frame is set to indicate the frame error con d ition. durin g the n e xt spi, the frame error bit i s sent out as spi_fra me bit (se e spi_frame in miso line in fig u re 6 ) . status.spi_frame bit is res e t, if c o rrec t frame is rec e ived. whe n a n inv a lid fram e i s received, the last co mm a nd i s si mply i gnored and t he regi ster contents are l e ft uncha nged. if fram e erro r ha ppe ns while se nd ing multiple sample s in rin g buffer mod e , only the last outpu t value is con s ide r ed invali d. 4.1.3 examples of spi communication 4.1.3.1 example of r e gister r ead an example o f 11 bit x-axis acceleration read comm an d is pre s e n te d in figure 7. the maste r gives the regi ste r a ddre s s to be read via th e mosi line: '0 5' in hex fo rm at and ' 0001 0 1' in bin a ry fo rmat, regi ster n a me is x_m sb (x-axis msb frame). 7 th bit is set to '0' to indicate the rea d operation. the se nsor replie s to a re que sted ope ration by tran sf errin g the re gister conte n t via miso li n e . after transfe rring t he a s ked x_ msb regi ster co ntent, the maste r give s next regi ste r address to b e re ad : '04' in hex format and ' 000 100' in bina ry format, re gister nam e is x _lsb (x-axi s lsb frame ) . the sen s o r re plie s to the req u e s ted op eratio n by transfe rri ng the regi ste r conte n t msb first. figure 7. an example of spi read co m m unication.
s c a3000 series vti technologie s oy 26/ 43 www.vti.fi doc.nr. 825 730 0a.07 rev.a.07 4.1.3.2 example of decreme n te d registe r re ad figure 8 p r e s ents a decre mented read operation wh ere the co nte n t of f our out put regi ste r s i s re ad by one spi frame. after no rmal re giste r addressin g a nd o n e re gist er co ntent re ading, th e c ke ep s the csb line low a nd con t inues su pply i ng the sck pulses. after every 8 sck pulses, the output data add re ss is decreme n t ed by one and the previ ous a c cele rat i on output re gister's conte n t is shifted out without p a rity bit s . th e p a rity bit in fi g u re 4 is cal c ul ated and t r an sferred o n ly for th e first data frame. from the x_ lsb registe r addre s s, the SCA3000 j u mps to z_ msb. decre m ented readi ng is p o ssi ble only for registe r s x_lsb ... z_msb. figure 8. an example of d e creme n ted read op eratio n . 4.1.3.3 example of r i ng buffe r re ad an exampl e of output ring buffer re ad b y one spi fr a m e (ring buff e r d a ta le ngt h 8 bits) is p r ese n ted in f i g u r e 9 . t h e w h o l e r i n g b u ffer re ad p r o c e d u r e is ve r y s i milar to d e c r eme n te d r e a d de sc r i bed above. th e output ri ng b u ffer is ad dressed (regi ster n a me b u f_data ). th e sca3 000 sen s o r contin ue s shif ting out the ring buffer cont ent as lon g a s c continu e s su pplying th e sck pulses. figure 9. an example of o u t put ring buff e r re ad op era t ion.
SCA3000 series vti technologies oy 27/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 4.2 i 2 c interface i 2 c is a 2-wire serial interface. it consists of one master device and one or more slave devices. the master is defined as a micro controller providing the serial clock (scl), and the slave as any integrated circuit receiving the scl clock from the master. the SCA3000 sensor always operates as a slave device in master-slave operation mode. when using an spi interface , a hardware addressing is used (slaves have dedicated csb signals), the i 2 c interface uses a software based addressing (slave devices have dedicated bit patterns as addresses). the SCA3000 is compatible to the philips i 2 c specification v2.1. main used features of the i 2 c interface are: - 10-bit addressing, SCA3000 i 2 c device address is 0x1f1 - supports standard mode and fast mode - start / restart / stop - slave transceiver mode - designed for low power consumption in addition to the philips specification, the SCA3000 i 2 c interface supports multiple write and read mode. 4.2.1 i 2 c frame format 4.2.1.1 i 2 c write mode in i 2 c write mode , the first 8 bits after device address def ine the SCA3000 internal register address to be written. if multiple data words are transf erred by the master, the register address is decreased automatically by one (see cases 1 and 2 in figure 10). 4.2.1.2 i 2 c read mode the read mode operates as described in philips i 2 c specification. i 2 c read operation returns the content of the register which address is defined in i2c_rd_sel register. so when performing the i 2 c read operation, the register address to be re ad has to be written into i2c_rd_sel register before actual read operation. read operation star ts from register address that has been written earlier in i2c_rd_sel register. read data is acknowledged by i 2 c master. automatic read address change depends on the selected start ad dress (see cases 3 and 4 in figure 10). - if address is some of registers between x_lsb ? z_msb the register address is automatically cycled as follows: ... ? y_msb ? y_lsb ? x_msb ? x_lsb ? z_msb ? z_lsb ? y_msb ? y_lsb ? ... - if the start address is any other register, the read address is no t automatically incremented or decremented (the data transfer continues from t he same address.) this enables the burst read from output ring buffer (register buf_data). 4.2.1.3 decremented register read decremented reading is possible only for regist ers x_lsb ... z_msb. refer to decremented read with spi interface section 4.1.3.2.
s c a3000 series vti technologie s oy 28/ 43 www.vti.fi doc.nr. 825 730 0a.07 rev.a.07 4.2.2 examples of i 2 c communication examples of i 2 c comm uni cation are p r e s ented bel ow i n figure 10. s 0 sa sa sa sa d e v i c e ad dr 1 s t by t e 111 1 0 a a d e v i c e ad dr 2n d by te aa aaaaa a r e g i s t er ad d r 8 b i ts , m s b firs t r e g i s t er da t a 8 b i ts , m s b firs t c ase 1: i2c 8 bit w r it e s 0 sa sa sa sa d e v i c e ad dr 1 s t by te 11 1 1 0aa d e v i c e ad dr 2n d by te aa aaaaa a r e g i s t er ad d r 8 b i ts , m s b firs t r e g i s t er da t a , ad d r + 0 8 b it s , m sb f i r s t case 2 : i2 c 1 6 b i t w r i t e (a n y n u m b e r of b y t e s c a n b e wri tte n, l e ng th i s de te r m i n ed b y e n d c o nd i t i on ge n e r a t e d b y m a s t e r ) sa r e g i s t er da t a , ad d r - 1 8 b i ts , ms b f i r s t e s 0 sa sa ma d e v i c e ad dr 1 s t by te 11 1 1 0aa d e v i c e ad dr 2n d by te aa aaaaa a r e g i s t er da t a , ad d r 8 b i ts , m s b first case 3 : i2 c 8 bi t re ad, r e ad a d dr es s f o r s c a 3 00 0 s e ri e s r e gi s t e r s h ou l d b e w r i tte n t o i2c _ r d _s e l re g i s t e r case 4 : i 2 c 16 b i t re ad (a n y nu mb er o f by t e s c a n be re ad , l e n g t h i s d e t e r m i n e d by en d c o n d i t i o n g e n e r a t e d by ma st e r ). a u to m a ti c r e gi s t er ad dr e s s c h a n gi n g d e pe nd s on s e l e c t ed s t ar t a d d r es s i n i2 c _ r d _ s e l ( n ot ed b y ad dr an d ad d r _x on t h e f i g u r e ). e s = s t ar t con d iti on rs = r e p e at ed s t a r t c o nd i t i o n e = en d c o n d it io n s a = s l av e a c k n o w l e d g em e n t m a = ma s t er a c k n o w l e dgem e n t aa = d e vi c e ad dr e s s , 10 b i t s r e a d /w r i te s e l e c t b i t (0 = w r i t e , 1 = r e a d ) rs d e v i c e ad dr 1 s t by te 11 1 1 0aa 1 sa s 0 sa sa ma d e v i c e ad dr 1 s t by te 11 1 1 0aa d e v i c e ad dr 2n d by te aa aaaaa a r e g i s t er da t a , ad d r 8 b i ts , m s b first e rs d e v i c e ad dr 1 s t by te 11 1 1 0aa 1 sa ma r e g i st er da t a , ad d r _x 8 bi t s , m s b fi rs t e figure 10. i 2 c frame format.
SCA3000 series vti technologies oy 29/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 5 electrical characteristics all voltages are reference to ground. currents fl owing into the circuit have positive values. 5.1 absolute maximum ratings the absolute maximum ratings of the SCA3000 are presented in table 15 below. table 15. absolute maximum ratings of the SCA3000 parameter value unit supply voltage (v dd ) -0.3 to +3.6 v voltage at input / output pins -0.3 to (v dd + 0.3) v esd (human body model) 2 kv storage temperature -40 ... +125 c storage / operating temperature -40 ... +85 c mechanical shock * > 10 000 g ultrasonic cleaning not allowed * 1 m drop on concrete may cause >>10000 g shock. ultrasonic agitation not allowed. 5.2 power supply please refer to the corresponding product datasheet. 5.3 digital i/o specification 5.3.1 digital i/o dc characteristics table 16. dc characteristics of digital i/o pins. no. parameter conditions symbol min typ max unit input: csb, mosi, xreset, sck_scl has no pull up / pull down 1 pull up current: csb v in = 0 v i pu 10 50 a 2 pull down current: mosi v in = dvio i pd 10 50 a 3 pull up current xreset v in = 0 v i pu 3 10 a 4 input high voltage v ih 0.7*dvio v 5 input low voltage v il 0.3*dvio v 6 hysteresis v hyst 0.1*dvio v output terminal: miso_sda, int 7 output high voltage i > -4 ma v oh 0.8*dvio dvio v 8 output low voltage i < 4 ma v ol 0 0.2*dvio v 9 tristate leakage 0 < v miso < 2.7 v i leak -2 2 a 5.3.2 digital i/o level shifter all the SCA3000 products have an internal level shifte r that can be used to interface e.g. a micro controller using lower supply than the SCA3000. the level shifter is "programmed" by providing the supply voltage of the interfaced device to the dvio-pin. please refer to the corresponding product data sheet for details.
s c a3000 series vti technologie s oy 30/ 43 www.vti.fi doc.nr. 825 730 0a.07 rev.a.07 5.3.3 spi ac cha racteristics the ac cha r acte risti cs of the sca30 00 spi interface are d e fined in figure 1 1 an d in table 17. cs b sc k mo si mi s o t ls 1 t ch t ho l t s et t va l1 t val 2 t lz t ls 2 t lh ms b i n ms b o u t ls b in ls b o u t dat a o u t dat a i n t cl figure 11. timing diag ram for spi communication. table 17. ac cha r a c teri stics of spi communication. param e ter conditions symbol min typ max unit terminal cs b, sck 1 time from csb (10%) to sck (90%)1 t ls1 t per / 2 ns 2 time from s c k (10% ) to csb (90%)1 t ls2 t per /2 ns terminal sck 3 sck low time load cap a cita nce at miso < 35 p f t cl 0 . 8 0 * t per /2 t per / 2 ns 4 sck high time load cap a cita nce at miso < 35 p f t ch 0.80* t per /2 t per /2 ns 5 sck freq uen cy fsck = 1/t per produ c t specific mhz terminal mosi, sck 6 time from ch angin g mosi (10%, 90%) to sck (90%)1. data setup time t set t per /4 ns 7 time from s c k (90% ) to chan ging mosi (10%, 90%)1. data hold time t hol t per / 4 ns terminal miso, csb 8 time from csb (10%) to stable miso (10%, 90%) load cap a cita nce at miso < 35 p f t val1 t per /4 ns 9 time from csb (90%) to high imped ance state of miso1. load cap a cita nce at miso < 35 p f t lz t per / 4 n s terminal miso, sck 10 time from s c k (10% ) to stable miso (10%, 90%)1. load cap a cita nce at miso < 35 p f t val2 1.3 t per /4 ns
s c a3000 series vti technologie s oy 31/ 43 www.vti.fi doc.nr. 825 730 0a.07 rev.a.07 terminal mosi, csb 11 time betwee n spi cycle s , csb at high level (90%) t lh 4 t per n s t per is sck period 5.3.4 i 2 c ac characteristics please, see phillips s e mi conductors, t he i 2 c bu s sp ecification, v e rsi on 2.1, ja nuary 200 0, pp. 31 - 33. 6 packag e characteristics 6.1 dimensions the package dimensions are presented in fi gure 12 below (dim ensi o ns in mi llimeters [mm ] with 50 m tolera nce ) . figure 12. sca300 0 pa ckage dime nsi o ns.
s c a3000 series vti technologie s oy 32/ 43 www.vti.fi doc.nr. 825 730 0a.07 rev.a.07 7 application information 7.1 pin description sca300 0 pin numbe rs a r e presented in figure 14 bel ow an d pin d e scriptio ns in table 18. figure 13. sca300 0 se nsing dire ction s . figure 14. sca300 0 pin n u mbe r s. table 18. SCA3000 pin d e s cription s. pin # nam e sca300 0-d0 1, SCA3000 -e01, sca300 0-e0 4 sca300 0-d0 2, SCA3000 -e02 1 nc not co nne cte d not co nne cte d 2 xreset external res e t, ac tive low external res e t, ac tive low 3 int interrupt output interrupt output 4 clk con n e c t to ground con n e c t to ground 5 d v s s digital ground d i g i t a l g r o u n d 6 dvd d digital supply digital supply 7 dvio digital i/o s u pply digital i/o s u pply 8 csb chip select not co nne ct e d 9 nc not co nne cte d not co nne cte d 10 nc not co nne ct e d not co nne ct e d 11 sck_scl spi s e rial c l oc k (sck) i 2 c seri al clo c k (s c l ) 12 miso_sda spi data out (miso) i 2 c data in / out (sda) 13 mosi spi data in (mosi) not co nne cte d 14 avdd analog sup p l y analog sup p l y 15 avss analog ground analog ground 16 avss analog g r ou n d analog g r ou n d 17 atstio not co nne cte d not co nne cte d 18 nc not co nne ct e d not co nne ct e d 7.2 recommended circuit diagram 1. con n e c t 100 nf smd capa citor bet wee n each sup p ly voltage and g r oun d level. 2. con n e c t 1 f capa citor b e twee n ea ch supply voltage and gro und l e vel. 3. use one regu lator for an alo g and digital sup p ly (avdd and dvdd). 4. use se parate regulato r for digital io sup p ly (dvio). 5. xreset is nee ded al ways in start up: wh e n xreset is lo w, raise po we r sup p lie s insi de spe c ification, then set xre s et high. 6. int-pi n is u s ed with outp u t buffer as we ll as in fre e f a ll and motio n dete ction mode. 7. serial interfa c e (spi or i 2 c) logical '1 ' level is determin ed by dvio supply voltage level. re comm end ed circuit dia g ram fo r the sca300 0 wit h spi interface is pre s e n te d in figure 15 below.
s c a3000 series vti technologie s oy 33/ 43 www.vti.fi doc.nr. 825 730 0a.07 rev.a.07 re comm end ed circuit dia g ram fo r the sca300 0 wit h i 2 c interface is pre s e n te d in figure 16 below. figure 15. re comm end ed circuit diag ra m for the SCA3000 with s p i interface. figure 16 . re comm end ed circuit diag ra m for the SCA3000 with i 2 c interfa c e. 7.3 recommended pwb lay out gene ral pwb layout reco m m endatio ns f o r sca30 00 prod uct s (refer to figu re 1 5 , figure 1 6 and figure 17): 1. locate 100 n f smd ca pa citors ri ght nex t to the SCA3000 pa ckag e. 2. 1 f capa cito rs can be lo cated nea r the node where avdd an d dvdd a r e ro uted on sepa rat e way s . 3. use se parate groun d plan e s for agnd a nd dg nd. conne ct se parate grou nd pl ane s togethe r on pwb. 4. use dou ble si ded pwb, co nne ct the bottom side pl an e to dgnd.
s c a3000 series vti technologie s oy 34/ 43 www.vti.fi doc.nr. 825 730 0a.07 rev.a.07 re comm end ed pwb pad l a yout for SCA3000 is p r e s ented in figu re 17 belo w (d imensi o n s in millimeters, [mm]). re comm end ed pwb layo ut for the SCA3000 with s p i interface is presented in figure 18 bel ow (ci r cuit diagra m pre s ente d in figure 15 a bove). figure 17. re comm end ed pwb pad lay out for sca3 000. figure 18. re comm end ed pwb layout for sca30 00 with spi interface (n ot actu al size, for referen c e onl y).
s c a3000 series vti technologie s oy 35/ 43 www.vti.fi doc.nr. 825 730 0a.07 rev.a.07 re comm end ed pwb layo ut for sca30 00 with i 2 c in terface i s pre s ente d in fig u re 19 b e lo w (ci r cuit diagram presented in figu re 16 above ) . figure 19. re comm end ed pwb layout for sca30 00 with i 2 c interf ace (not actu al size, for refe ren c e only ) . 7.4 assembl y instructions the m o istu re sensitivity l e vel (msl ) of the sca3 00 0 compo nent is 3 acco rdi n g to the ip c/jedec j-st d-020 c. please refe r to the do cument "t n5 4 sca300 0 assembly instruction s " fo r more detailed info rmation of SCA3000 a s sem b ly. 7.5 tape and reel specifications please refe r to the do cume nt "tn54 sca30 00 asse mbly instruction s " fo r tape a n d reel specifications.
s c a3000 series vti technologie s oy 36/ 43 www.vti.fi doc.nr. 825 730 0a.07 rev.a.07 8 data sheet references 8.1 offset sca300 0's offset will b e ca librated i n x = 0 g, y = 0 g , and z = +1 g (z m e a s uri ng axis i s p a rallel to earth? s gravitation) po sitio n , see figu re 20. z-axis in +1 g positio n y earth?s gravitation x pin #1 figure 20. sca300 0 offse t (0 g) po sitio n . 8.1.1 offset calibration error offset calib ra tion error is th e differen c e b e twee n the sensor' s a c tual output readi n g and the no minal output rea d in g in calib ratio n con d ition s . erro r is calcul ated by equation 2 1000 ? ? = ? ? , whe r e out put x-axiscali ber is sensor? s x-axi s cali bration error in [mg], out put x-axis is se nsor? s x - axis output re adin g [cou nts], ou tpu t is sen s o r ?s n o min a l o u tput in 0 g p o sition and se ns se ns or ?s no min a l sen s itivity [counts/g]. 8.1.2 offset temp erature error offset temp e r ature e r ror is the difference b e tw ee n the sen s o r 's outp u t re ading in diff eren t temperature s and the se nsor?s calib rate d offset valu e at room tem peratu r e. error is calculate d by equation 3 1000 @ @ @ ? ? = ? ? ? , whe r e ou tpu t x-axistemp e r@ t is sen s o r ?s x-ax is temp eratu r e erro r in [mg ] in tempe r at ure t , ou tpu t x-axis@t is sen s o r ?s x - axis output r eadi ng [ c ou nts] in te mpe r ature t , o u t put x-axis@t x-axis outp u t re adi n g [count s] at ro om tempe r at ure rt an d sen s sen s o r ?s nominal se nsitivity [counts/ g]. senso r is in 0 g positio n for e v ery measure m ent point.
s c a3000 series vti technologie s oy 37/ 43 www.vti.fi doc.nr. 825 730 0a.07 rev.a.07 8.2 sensitivity duri ng se nsit ivity calibrati on, the sen s or is pl a c e d in 1 g p o sit i ons having one of the sensor? s measuri ng ax is at a time parallel to t he earth? s gravitation, see fig u re 21. sensitivity is cal c ulate d by equation 4 g output output sens g axis y g axis y axis y 2 1 @ 1 @ ? ? + ? ? ? = , whe r e se ns y- a x i s is sensor? s y-axis se n s itivity in [counts/g], out p ut y - axis@+1g senso r ?s y-axis output readi ng [coun ts] in +1 g po sition a nd out put y - axis@-1g is s e ns or ?s y- a x is o u t pu t r e adin g [c ou n t s ] in - 1 g positio n. pin #1 x y-axis in +1 g positio n z x z y-axis in -1 g positio n earth?s gravitation pin #1 figure 21 . sca300 0 po sitions for y - ax is se nsitivity measurement . 8.2.1 sensitivity calibration error sensitivity cal i bration e rro r is the differen c e betw een sensor? s m e a s ured sen s itivity and t he no minal sen s itivity at room tempe r a t ure co ndition s. erro r is cal c ulate d by equation 5 % 100 ? ? = ? ? sens sens sens sens axis y r axiscalibe y , whe r e sens y - a x iscaliber is sensor? s y-axis sensit ivity calibration error in [%], sens y-axis sensor? s y-axis sen s itivity [counts/g] at room tempe r ature conditi ons a nd se n s is se nsor? s nominal se nsitivity [count s/g]. 8.2.2 sensitivity temperature error sensitivity te mperature e r ror is t he difference betwee n sen s o r ?s se nsit ivity at different temp erature s and the calibrated se nsitivity. error is cal c ulate d by equation 6 % 100 @ @ @ @ ? ? = ? ? ? ? rt axis y rt axis y t axis y t axistemper y sens sens sens sens , whe r e se ns y- a x i s t e m p e r @ t is sensor?s y-axis se n s itivity te mperature e r ror in [%] in te mperature t , sen s y- axis@t is sen s o r ?s m e a s u r ed y-axis sen s iti v ity [counts/g] at tempe r atu r e t and se ns y - axis@rt is sensor? s measured y-axis se nsitivity [c ounts/g] a t room tempe r ature rt .
s c a3000 series vti technologie s oy 38/ 43 www.vti.fi doc.nr. 825 730 0a.07 rev.a.07 8.3 linearit y the lin earity error ch ara c t e rization m e thod d e scribe d belo w i s a pplied fo r tho s e s c a300 0 seri e s comp one nts that have mea s uri ng rang e 3g o r belo w . accu rate i n p u t accele ratio n nee ded i n linearity cha r a c teri zation i s gene rated usi ng centrifug a l force in ce ntrifug e , see figu re 22. the rpm of the centrifuge is sweep ed so that wa nted inpu t accele ration values a r e ap plied in pa rall el to the sen s or?s m e a s uri n g axis. linea rity erro r is the devia tion from the straig ht line t h rou gh sen s or?s se nsitivity calibration points, see fig u re 23 . linea rity erro r is calcul ated by equation 7 % 100 @ @ @ ? ? ? = ? ? , w h er e line r z-axis@acc is sen s or?s z - axis lin earity e r ror [ % fs] on in pu t accele ration acc , ou tpu t z-axis@acc is sen s or? s measured z - axis outp u t [cou nts] on i nput a c celeration acc , ou tpu t @acc is sensor? s x y z centrifu gal accele ration for z-axis pin #1 figure 22. ce ntrifugal a c ce leration a ppli ed for sca30 00 z-axi s . input acceleration [g] (centrifugal acceler a tion in par allel to SCA3000 measu r ing axis) SCA3000 output at positive sens itiv it y calibration point SCA3000 linearit y error in [g] at inp u t acceleration acc +1 g -1 g possible offset error is not included into line a rit y er ror SCA3000 output readings sensor?s ideal output acceleration reading from SCA3000 [g ] acc figure 23. sca300 0?s lin earity error at input accele ration acc .
s c a3000 series vti technologie s oy 39/ 43 www.vti.fi doc.nr. 825 730 0a.07 rev.a.07 nominal o u tp ut [counts] on input acceleration acc , sen s is sen s o r ?s nominal sen s i t ivity [counts/ g] and fs is sen s o r ?s full scale me asu r ing ran g e [g] (for example for sca3 000-d0 1 2 g fs = 2 g). senso r ? s ide a l output o u t put @acc (in e quation 7) is cal c ulate d f r om th e st ra ight line th ro ugh sen s itivity calibration p o ints (the red strai ght line in fig u re 23 ). nomi nal output is cal c ulate d by equation 8 2 2 2 1 1 1 1 1 1 @ g g g g g g acc output output g output output acc offset g output output acc output ? + ? + ? + + + ? ? = + ? ? = , whe r e ou tpu t @acc is senso r ?s nomin al ou tput [counts] with input a c cele ration acc in [g], out put +1g is sen s o r ?s m e a s ured outp u t [count s] at +1 g input acceleratio n and outp ut -1g is sensor? s mea s ure d output at -1 g input a c cel e ration. po ssible o ffset term [cou nts] is inclu ded i n to nomin al o u tput, becau se it is not inclu ded i n to linearity error. 8.4 noise output n o ise n x , n y and n z in x,y and z dire ction s i s t he me asur ed stan dard d e viation of th e o u tput values whe n the se nsor is i n 0 g positio n at room tem peratu r e. average n o ise/axis is calculate d by equation 9 () 2 2 2 3 1 z y x n n n n + + = , whe r e n i s se nso r ?s noi se [g] per axis, n x is sensor?s x-axis noi se [ g ], n y is sensor?s y-axi s noise [g] and n z is s e ns or?s z-axis nois e [g]. sca300 0 de mo-kit de sign can be use d as a refere nce de sign f o r n o ise me a s ureme n ts, refer to ?sca30 00 demo kit user man ual 82 5930 0?. 8.5 bandw idth signal b and width i s m e a s ured i n a shaker by sweepin g the p i ston m o vem ent freq uen cy with con s tant amp litude (fig ure 24). z earth?s gravitation shake r movement in parall e l to z-axis y x pin #1 figure 24. sca300 0 mov e ment in z-ax is ban dwi d th measurement . 8.6 cross-axis sensitivity cross-axis sensitivity is sum of the alignme n t an d the i nhe re nt sensitivity erro rs. cr o s s - ax i s sen s itivity of one axis i s a geomet ric su m of the sen s itivities in two perpe ndi cula r dire ction s . cross-axis sensitivity [%] of x-axis is giv en by
s c a3000 series vti technologie s oy 40/ 43 www.vti.fi doc.nr. 825 730 0a.07 rev.a.07 equation 10 %, 100 2 2 ? + = x xz xy x s s s cross whe r e s xy i s x-axis sensiti v ity to y-axis acc e leration [count/g], s xz is x-axis sensit ivity to z-axis accele ration [ c ou nt/g] and s x is sens itivity of x-axis [count/g]. cross-axis sensitivity [%] of y-axis is giv en by equation 11 %, 100 2 2 ? + = y yz yx y s s s cross whe r e s yx is y-axis sensiti v ity to x-axis ac c e leration [count/g], s yz is y-axis sensitivity to z-axis accele ration [ c ou nt/g] and s y is s e ns itivity of y-axis [count/g]. cross-axis sensitivity [%] of z-axis is give n by equation 12 %, 100 2 2 ? + = z zy zx z s s s cross whe r e s zx is z-axis sensiti v ity to x-axis ac celeration [count/g], s zy is z - axis sensitivity to y-axis accele ration [ c ou nt/g] and s z is s e ns itivity of z-axis [count/g]. cro s s-axis sensitivity of sca300 0 fa mily is mea s ured i n centri fuge over sp ecified m e a s urem ent rang e d u ri ng qualifi c ation . co rre ct m ounting po sit i on of co mp onent i s im portant du rin g the measurement of cro s s-axis sen s itivity. 8.7 turn-on time turn -on time is th e time whe n the la st of on e x, y, z axis outp u t readi ng s stabilizes into i t s fina l value after x r eset is pul led hi gh. the final value lim its in turn-on time me asurements i s defi ned to be 1 % of the se nsor? s full scale measur i ng range (for example fo r sca300 0-d01 2g fs = 2 g ) . turn-on time d e finition for z-ax is is presente d in figure 25 below. SCA3000 output inside 1% fs limits SCA3000 z-a x is output acceler a tion turn on time t i me scale xreset rise up SCA3000 sta r ts figure 25. tu rn-on time de finition for on e axis.
SCA3000 series vti technologies oy 41/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 9 order information order code description packing quantity SCA3000-d01-1 3-axis accelerometer with spi interface, +/-2g, 100 pcs t&r 100 SCA3000-d01-10 3-axis accelerometer with spi interface, +/-2g, 1000 pcs t&r 1000 SCA3000-d01-25 3-axis accelerometer with spi interface, +/-2g, 2500 pcs t&r 2500 SCA3000-d02-1 3-axis accelerometer with i2c interface, +/-2g, 100 pcs t&r 100 SCA3000-d02-10 3-axis accelerometer with i2c interface, +/-2g, 1000 pcs t&r 1000 SCA3000-d02-25 3-axis accelerometer with i2c interface, +/-2g, 2500 pcs t&r 2500 SCA3000-e01-1 3-axis accelerometer with spi interface, +/-3g, 100 pcs t&r 100 SCA3000-e01-10 3-axis accelerometer with spi interface, +/-3g, 1000 pcs t&r 1000 SCA3000-e01-25 3-axis accelerometer with spi interface, +/-3g, 2500 pcs t&r 2500 SCA3000-e02-1 3-axis accelerometer with i2c interface, +/-3g, 100 pcs t&r 100 SCA3000-e02-10 3-axis accelerometer with i2c interface, +/-3g, 1000 pcs t&r 1000 SCA3000-e02-25 3-axis accelerometer with i2c interface, +/-3g, 2500 pcs t&r 2500 SCA3000-e04-1 3-axis accelerometer with spi interface, +/-6g, 100 pcs t&r 100 SCA3000-e04-10 3-axis accelerometer with spi interface, +/-6g, 1000 pcs t&r 1000 SCA3000-e04-25 3-axis accelerometer with spi interface, +/-6g, 2500 pcs t&r 2500 SCA3000-e05-1 3-axis accelerometer with spi interface, +/-18g, 100 pcs t&r 100 SCA3000-e05-10 3-axis accelerometer with spi interface, +/-18g, 1000 pcs t&r 1000 SCA3000-e05-25 3-axis accelerometer with spi interface, +/-18g, 2500 pcs t&r 2500 SCA3000-d01 pwb pwb assy, 3-axis accelerometer with spi interface, +/-2g bulk 1 SCA3000-d02 pwb pwb assy, 3-axis accelerometer with i2c interface, +/-2g bulk 1 SCA3000-e01 pwb pwb assy, 3-axis accelerometer with spi interface, +/-3g bulk 1 SCA3000-e02 pwb pwb assy, 3-axis accelerometer with i2c interface, +/-3g bulk 1 SCA3000-e04 pwb pwb assy, 3-axis accelerometer with spi interface, +/-6g bulk 1 SCA3000-e05 pwb pwb assy, 3-axis accelerome ter with spi interface, +/-18g bulk 1 SCA3000-d01demo SCA3000-d01 demokit bulk 1
SCA3000 series vti technologies oy 42/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 10 document change control version date change description 0.01 09.09.2005 initial draft. .... ... 0.08 20.09.2005 draft release for schematic and layout design. 0.09 23.09.2005 ff and md description added. 0.10 12.10.2005 introduction and functional descriptions edited, measurement mode, ring buffer, temperature measurement, interrupt, oscillator, reset and register descriptions added. register and bit nam es changed to be more descriptive. 0.11 13.10.2005 typo etc minor corrections. 0.12 14.10.2005 draft release. 0.13 01.11.2005 register initial values and examples added. 0.14 09.11.2005 language corrections. 0.15 26.01.2006 new product versions updated. output and ring buffer bit level definitions changed. this definition is valid from samples v0.3 onwards. register level changes in temperature output. 0.16 15.02.2006 updated: - absolute maximum ratings, - temperature output equation, - i 2 c device address, specification references 0.17 14.03.2006 updated: - recommended circuit diagrams, sections ?packing? and ?handling and storage? added 0.18 27.03.2006 layout change a 27.04.2006 updated: - recommended circuit diagrams, - sections ?packing? and ?handling and storage? - section ?specification references? updated and renamed to ?data sheet references? md threshold levels a.01 27.06.2006 updated: - document name changed to "SCA3000 pr oduct family specification" - section "6.1 package dimensions" updated sections "7.4 solder paste and stencil parameters" and "7.5 reflow" updated to "7.4 assembly instructions" - section "9.1 packing and handling" updated to "7.5 tape and reel specifications" contact information a.02 30.6.2006 order information added a.03 11.9.2006 SCA3000-e04 information added a.04 27.03.2007 added: - SCA3000-e04 wide band measurement mode, - typos corrected - new product types: SCA3000-e05 and SCA3000-l01 a.05 01.06.2007 added: - new product type: SCA3000-d03 - i2c communication added for SCA3000-l01 a.06 30.10.2007 corrections: typos, axis orientation a.07 02.02.2009 corrected recommended pwb layouts. removed references to d03 and l01.
SCA3000 series vti technologies oy 43/ 43 www.vti.fi doc.nr. 8257300a.07 rev.a.07 11 contact information finland (head office) vti technologies oy p.o. box 27 myllynkivenkuja 6 fi-01621 vantaa finland tel. +358 9 879 181 fax +358 9 8791 8791 e-mail: sales@vti.fi germany vti technologies oy branch office frankfurt rennbahnstrasse 72-74 d-60528 frankfurt am main, germany tel. +49 69 6786 880 fax +49 69 6786 8829 e-mail: sales.de@vti.fi usa vti technologies, inc. one park lane blvd. suite 804 - east tower dearborn, mi 48126 usa tel. +1 313 425 0850 fax +1 313 425 0860 e-mail: sales@vtitechnologies.com japan vti technologies oy tokyo office tokyo-to, minato-ku 2-7-16 bureau toranomon 401 105-0001 japan tel. +81 3 6277 6618 fax +81 3 6277 6619 e-mail: sales.japan@vti.fi china vti technologies shanghai office 6th floor, room 618 780 cailun lu pudong new area 201203 shanghai p.r. china tel. +86 21 5132 0417 fax +86 21 513 20 416 e-mail: sales.china@vti.fi to find out your local sales representative visit www.vti.fi

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