View LTC1407A-1-15_9039229.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

ltc1407-1/ltc1407a-1 1 14071fb block diagram description serial 12-bit/14-bit, 3msps simultaneous sampling adcs with shutdown the ltc ? 1407-1/ltc1407a-1 are 12-bit/14-bit, 3msps adcs with two 1.5msps simultaneously sampled differ- ential inputs. the devices draw only 4.7ma from a single 3v supply and come in a tiny 10-lead ms package. a sleep shutdown feature lowers power consumption to 10w. the combination of speed, low power and tiny package makes the ltc1407-1/ltc1407a-1 suitable for high speed, portable applications. the ltc1407-1/ltc1407a-1 contain two separate differ- ential inputs that are sampled simultaneously on the rising edge of the conv signal. these two sampled inputs are then converted at a rate of 1.5msps per channel. the 80db common mode rejection allows users to eliminate ground loops and common mode noise by measuring signals differentially from the source. the devices convert C1.25v to 1.25v bipolar inputs differ- entially. the absolute voltage swing for ch0 + , ch0 C , ch1 + and ch1 C extends from ground to the supply voltage. the serial interface sends out the two conversion results in 32 clocks for compatibility with standard serial interfaces. l , lt, ltc, ltm, linear technology and the linear logo are registered trademarks of linear technology corporation. all other trademarks are the property of their respective owners. protected by u.s. patents including 6084440, 6522187. thd, 2nd and 3rd vs input frequency for differential input signals features applications n 3msps sampling adc with two simultaneous differential inputs n 1.5msps throughput per channel n low power dissipation: 14mw (typ) n 3v single supply operation n 1.25v differential input range n pin compatible 0v to 2.5v input range version (ltc1407/ltc1407a) n 2.5v internal bandgap reference with external overdrive n 3-wire serial interface n sleep (10w) shutdown mode n nap (3mw) shutdown mode n 80db common mode rejection at 100khz n tiny 10-lead ms package n telecommunications n data acquisition systems n uninterrupted power supplies n multiphase motor control n i & q demodulation n industrial radio C + 1 2 7 3 6 s & h C + 4 5 s & h gnd 11 exposed pad v ref 10f ch0 C ch0 + ch1 C ch1 + 3v 10f ltc1407a-1 8 10 9 three- state serial output port mux 2.5v reference timing logic v dd sdo conv sck 1407a1 bd 3msps 14-bit adc 14-bit latch 14-bit latch frequency (mhz) 0.1 C80 thd, 2nd, 3rd (db) C74 C68 C62 C56 11020 14071 ta01b C86 C92 C98 C104 C50 C44 thd 3rd 2nd
ltc1407-1/ltc1407a-1 2 14071fb pin configuration absolute maximum ratings supply voltage (v dd ) .................................................4v analog input voltage (note 3) ..... C 0.3v to (v dd + 0.3v) digital input voltage .................... C 0.3v to (v dd + 0.3v) digital output voltage ................. C 0.3v to (v dd + 0.3v) power dissipation ...............................................100mw operation temperature range ltc1407c-1/ltc1407ac-1 ...................... 0c to 70c ltc1407i-1/ltc1407ai-1 .....................C 40c to 85c storage temperature range ...................C 65c to 150c lead temperature (soldering, 10 sec) .................. 300c (notes 1, 2) 1 2 3 4 5 ch0 + ch0 C v ref ch1 + ch1 C 10 9 8 7 6 conv sck sdo v dd gnd top view 11 mse package 10-lead plastic msop t jmax = 125c, ja = 40c/w exposed pad is gnd (pin 11), must be soldered to pcb order information lead free finish tape and reel part marking package description temperature range ltc1407cmse-1#pbf ltc1407cmse-1#trpbf ltbgt 10-lead plastic msop 0c to 70c ltc1407imse-1#pbf ltc1407imse-1#trpbf ltbgv 10-lead plastic msop C40c to 85c ltc1407acmse-1#pbf ltc1407acmse-1#trpbf ltbgw 10-lead plastic msop 0c to 70c ltc1407aimse-1#pbf ltc1407aimse-1#trpbf ltbgx 10-lead plastic msop C40c to 85c consult ltc marketing for parts speci? ed with wider operating temperature ranges. consult ltc marketing for information on non-standard lead based ? nish parts. for more information on lead free part marking, go to: http://www.linear.com/leadfree/ for more information on tape and reel speci? cations, go to: http://www.linear.com/tapeandreel/ converter characteristics ltc1407-1 ltc1407a-1 parameter conditions min typ max min typ max resolution (no missing codes) l 12 14 bits integral linearity error (notes 5, 17) l C2 0.25 2 C4 0.5 4 lsb offset error (notes 4, 17) l C10 1 10 C20 2 20 lsb offset match from ch0 to ch1 (note 17) C5 0.5 5 C10 1 10 lsb gain error (notes 4, 17) l C30 5 30 C60 10 60 lsb gain match from ch0 to ch1 (note 17) C5 1 5 C10 2 10 lsb gain tempco internal reference (note 4) external reference 15 1 15 1 ppm/c ppm/c the l denotes the speci? cations which apply over the full operating temperature range, otherwise speci? cations are at t a = 25c. with internal reference, v dd = 3v.
ltc1407-1/ltc1407a-1 3 14071fb dynamic accuracy the l denotes the speci? cations which apply over the full operating temperature range, otherwise speci? cations are at t a = 25c. with internal reference, v dd = 3v. single-ended signal drive ch0 + /ch1 + with cho C /ch1 C = 1.5v dc. differential signals drive both inputs of each channel with v cm = 1.5v dc. ltc1407-1 ltc1407a-1 symbol param eter conditions min typ max min typ max units sinad signal-to-noise plus distortion ratio 100khz input signal (note 19) 750khz input signal (note 19) 100khz input signal, external v ref = 3.3v, v dd 3.3v (note 19) 750khz input signal, external v ref = 3.3v, v dd 3.3v (note 19) l 68 70.5 70.5 72.0 72.0 70 73.5 73.5 76.3 76.3 db db db db thd total harmonic distortion 100khz first 5 harmonics (note 19) 750khz first 5 harmonics (note 19) l C87 C83 C77 C90 C86 C80 db db sfdr spurious free dynamic range 100khz input signal (note 19) 750khz input signal (note 19) 87 83 90 86 db db imd intermodulation distortion 0.625v p-p 1.4mhz summed with 0.625v p-p , 1.56mhz into ch0 + and inverted into cho C . also applicable to ch1 + and ch1 C C82 C82 db code-to-code transition noise v ref = 2.5v (note 17) 0.25 1 lsb rms full power bandwidth v in = 2.5v p-p , sdo = 11585lsb p-p (C3dbfs) (note 15) 50 50 mhz full linear bandwidth s/(n + d) 68db 5 5 mhz the l denotes the speci? cations which apply over the full operating temperature range, otherwise speci? cations are at t a = 25c. with internal reference, v dd = 3v. symbol parameter conditions min typ max units v in analog differential input range (notes 3, 8, 9) 2.7v v dd 3.3v C1.25 to 1.25 v v cm analog common mode + differential input range (note 10) 0 to v dd v i in analog input leakage current l 1a c in analog input capacitance (note 18) 13 pf t acq sample-and-hold acquisition time (note 6) l 39 ns t ap sample-and-hold aperture delay time 1 ns t jitter sample-and-hold aperture delay time jitter 0.3 ps t sk sample-and-hold aperture skew from ch0 to ch1 200 ps cmrr analog input common mode rejection ratio f in = 1mhz, v in = 0v to 3v f in = 100mhz, v in = 0v to 3v C60 C15 db db analog input
ltc1407-1/ltc1407a-1 4 14071fb internal reference characteristics t a = 25c. v dd = 3v. digital inputs and digital outputs the l denotes the speci? cations which apply over the full operating temperature range, otherwise speci? cations are at t a = 25c. v dd = 3v. parameter conditions min typ max units v ref output voltage i out = 0 2.5 v v ref output tempco 15 ppm/c v ref line regulation v dd = 2.7v to 3.6v, v ref = 2.5v 600 v/v v ref output resistance load current = 0.5ma 0.2 v ref setting time 2ms symbol parameter conditions min typ max units v ih high level input voltage v dd = 3.3v l 2.4 v v il low level input voltage v dd = 2.7v l 0.6 v i in digital input current v in = 0v to v dd l 10 a c in digital input capacitance 5pf v oh high level output voltage v dd = 3v, i out = C200a l 2.5 2.9 v v ol low level output voltage v dd = 2.7v, i out = 160a v dd = 2.7v, i out = 1.6ma l 0.05 0.10 0.4 v v i oz hi-z output leakage d out v out = 0v to v dd l 10 a c oz hi-z output capacitance d out 1pf i source output short-circuit source current v out = 0v, v dd = 3v 20 ma i sink output short-circuit sink current v out = v dd = 3v 15 ma power requirements the l denotes the speci? cations which apply over the full operating temperature range, otherwise speci? cations are at t a = 25c. with internal reference, v dd = 3v. symbol parameter conditions min typ max units v dd supply voltage 2.7 3.6 v i dd supply current active mode, f sample = 1.5msps nap mode sleep mode (ltc1407) sleep mode (ltc1407a) l l 4.7 1.1 2.0 2.0 7.0 1.5 15 10 ma ma a a pd power dissipation active mode with sck in fixed state (hi or lo) 12 mw
ltc1407-1/ltc1407a-1 5 14071fb note 1: stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. exposure to any absolute maximum rating condition for extended periods may affect device reliability and lifetime. note 2: all voltage values are with respect to ground gnd. note 3: when these pins are taken below gnd or above v dd , they will be clamped by internal diodes. this product can handle input currents greater than 100ma below gnd or greater than v dd without latchup. note 4: offset and range speci? cations apply for a single-ended ch0 + or ch1 + input with ch0 C or ch1 C grounded and using the internal 2.5v reference. note 5: integral linearity is tested with an external 2.55v reference and is de? ned as the deviation of a code from the straight line passing through the actual endpoints of a transfer curve. the deviation is measured from the center of quantization band. note 6: guaranteed by design, not subject to test. note 7: recommended operating conditions. note 8: the analog input range is de? ned for the voltage difference between ch0 + and ch0 C or ch1 + and ch1 C . performance is speci? ed with cho C = 1.5v dc while driving cho + and with ch1 C = 1.5v dc while driving ch1 + . note 9: the absolute voltage at ch0 + , ch0 C , ch1 + and ch1 C must be within this range. symbol parameter conditions min typ max units f sample(max) maximum sampling frequency per channel (conversion rate) l 1.5 mhz t throughput minimum sampling period (conversion + acquisition period) l 667 ns t sck clock period (note 16) l 19.6 10000 ns t conv conversion time (note 6) 32 34 sclk cycles t 1 minimum positive or negative sclk pulse width (note 6) 2 ns t 2 conv to sck setup time (notes 6, 10) 3 10000 ns t 3 sck before conv (note 6) 0 ns t 4 minimum positive or negative conv pulse width (note 6) 4 ns t 5 sck to sample mode (note 6) 4 ns t 6 conv to hold mode (notes 6, 11) 1.2 ns t 7 32nd sck to conv interval (affects acquisition period) (notes 6, 7, 13) 45 ns t 8 minimum delay from sck to valid bits 0 through 11 (notes 6, 12) 8 ns t 9 sck to hi-z at sdo (notes 6, 12) 6 ns t 10 previous sdo bit remains valid after sck (notes 6, 12) 2 ns t 12 v ref settling time after sleep-to-wake transition (notes 6, 14) 2 ms timing characteristics the l denotes the speci? cations which apply over the full operating temperature range, otherwise speci? cations are at t a = 25c. v dd = 3v. note 10: if less than 3ns is allowed, the output data will appear one clock cycle later. it is best for conv to rise half a clock before sck, when running the clock at rated speed. note 11: not the same as aperture delay. aperture delay (1ns) is the difference between the 2.2ns delay through the sample-and-hold and the 1.2ns conv to hold mode delay. note 12: the rising edge of sck is guaranteed to catch the data coming out into a storage latch. note 13: the time period for acquiring the input signal is started by the 32nd rising clock and it is ended by the rising edge of conv. note 14: the internal reference settles in 2ms after it wakes up from sleep mode with one or more cycles at sck and a 10f capacitive load. note 15: the full power bandwidth is the frequency where the output code swing drops by 3db with a 2.5v p-p input sine wave. note 16: maximum clock period guarantees analog performance during conversion. output data can be read with an arbitrarily long clock period. note 17: the ltc1407a-1 is measured and speci? ed with 14-bit resolution (1lsb = 152v) and the ltc1407-1 is measured and speci? ed with 12-bit resolution (1lsb = 610v). note 18: the sampling capacitor at each input accounts for 4.1pf of the input capacitance. note 19: full-scale sinewaves are fed into the noninverting inputs while the inverting inputs are kept at 1.5v dc.
ltc1407-1/ltc1407a-1 6 14071fb typical performance characteristics snr vs input frequency enobs and sinad vs input sinewave frequency for differential input signals thd, 2nd and 3rd vs input frequency for differential input signals sfdr vs input frequency for differential input signals 98khz sine wave 4096 point fft plot 748khz sine wave 4096 point fft plot enobs and sinad vs input sinewave frequency thd, 2nd and 3rd vs input frequency sfdr vs input frequency v dd = 3v, t a = 25c. single-ended signals drive +ch0/+ch1 with Cch0/Cch1 = 1.5v dc, differential signals drive both inputs with v cm = 1.5v dc (ltc1407a-1) frequency (mhz) 0.1 10.0 enobs (bits) sinad (db) 11.0 12.0 1 10 100 14071 g01 9.0 9.5 10.5 11.5 8.5 8.0 62 68 74 56 59 65 71 53 50 frequency (mhz) 0.1 C80 thd, 2nd, 3rd (db) C74 C68 C62 C56 1 10 100 14071 g02 C86 C92 C98 C104 C50 C44 thd 3rd 2nd frequency (mhz) 0.1 62 snr (db) 56 50 1 10 100 14071 g04 68 65 59 53 71 74 frequency (mhz) 0.1 10.0 enobs (bits) sinad (db) 11.0 12.0 1 10 100 14071 g05 9.0 9.5 10.5 11.5 8.5 8.0 62 68 74 56 59 65 71 53 50 frequency (mhz) 0.1 68 sfdr (db) 56 44 1 10 100 14071 g03 80 74 62 50 86 92 98 104 frequency (mhz) 0.1 C80 thd, 2nd, 3rd (db) C74 C68 C62 C56 11020 14071 g06 C86 C92 C98 C104 C50 C44 thd 3rd 2nd frequency (mhz) 0.1 68 sfdr (db) 56 44 1 10 100 14071 g07 80 74 62 50 86 92 98 104 frequency (khz) magnitude (db) C60 C30 C20 14071 g08 C70 C80 C120 C100 0 C10 C40 C50 C90 C110 0 200 400 100 300 600 500 700 frequency (khz) 0 magnitude (db) C60 C30 C20 14071 g09 C70 C80 C120 200 400 100 300 600 500 700 C100 0 C10 C40 C50 C90 C110
ltc1407-1/ltc1407a-1 7 14071fb typical performance characteristics differential linearity for ch0 with internal 2.5v reference integral linearity end point fit for ch0 with internal 2.5v reference integral linearity end point fit for ch0 with internal 2.5v reference for differential input signals differential linearity for ch1 with internal 2.5v reference integral linearity end point fit for ch1 with internal 2.5v reference 1403khz input summed with 1563khz input imd 4096 point fft plot for differential input signals 748khz sine wave 4096 point fft plot for differential input signals 10.7mhz sine wave 4096 point fft plot for differential input signals v dd = 3v, t a = 25c. single-ended signals drive +ch0/+ch1 with Cch0/Cch1 = 1.5v dc, differential signals drive both inputs with v cm = 1.5v dc (ltc1407a-1) integral linearity end point fit for ch1 with internal 2.5v reference for differential input signals frequency (khz) 0 magnitude (db) C60 C30 C20 14071 g10 C70 C80 C120 200 400 100 300 600 500 700 C100 0 C10 C40 C50 C90 C110 frequency (hz) magnitude (db) C60 C30 C20 14071 g11 C70 C80 C120 C100 0 C10 C40 C50 C90 C110 0 371k 185k 556k 741k frequency (hz) magnitude (db) C60 C30 C20 14071 g12 C70 C80 C120 C100 0 C10 C40 C50 C90 C110 0 371k 185k 556k 741k output code 0 C1.0 differential linearity (lsb) C0.8 C0.4 C0.2 0 1.0 0.4 4096 8192 14071 g13 C0.6 0.6 0.8 0.2 12288 16384 output code 0 C4.0 integral linearity (lsb) C3.2 C1.6 C0.8 0 4.0 1.6 4096 8192 14071 g14 C2.4 2.4 3.2 0.8 12288 16384 output code 0 C4.0 integral linearity (lsb) C3.2 C1.6 C0.8 0 4.0 1.6 4096 8192 14071 g15 C2.4 2.4 3.2 0.8 12288 16384 output code 0 C1.0 differential linearity (lsb) C0.8 C0.4 C0.2 0 1.0 0.4 4096 8192 14071 g16 C0.6 0.6 0.8 0.2 12288 16384 output code 0 C4.0 integral linearity (lsb) C3.2 C1.6 C0.8 0 4.0 1.6 4096 8192 14071 g17 C2.4 2.4 3.2 0.8 12288 16384 output code 0 C4.0 integral linearity (lsb) C3.2 C1.6 C0.8 0 4.0 1.6 4096 8192 14071 g18 C2.4 2.4 3.2 0.8 12288 16384
ltc1407-1/ltc1407a-1 8 14071fb typical performance characteristics v dd = 3v, t a = 25c. single ended signals drive +ch0/+ch1 with Cch0/Cch1 = 1.5v dc, differential signals drive both inputs with v cm = 1.5v dc (ltc1407a-1) full-scale signal frequency response cmrr vs frequency crosstalk vs frequency output match with simultaneous input steps at ch0 and ch1 from 25 pssr vs frequency differential and integral linearity vs conversion rate sinad vs conversion rate v dd = 3v, t a = 25c (ltc1407-1/ltc1407a-1) conversion rate (msps) 2 linearity (lsb) 2 5 6 4 14071 g19 1 0 C4 2.5 2.75 2.25 3 3.25 3.5 3.75 C2 8 7 4 3 C1 C3 max inl max dnl min dnl min inl conversion rate (msps) 2 2.5 3 3.5 4 68 s/(n+d) (db) 69 71 72 73 78 75 14071 g20 70 76 77 74 external v ref = 3.3v, f in ~ fs/3 external v ref = 3.3v, f in ~ fs/40 internal v ref = 2.5v, f in ~ fs/3 internal v ref = 2.5v, f in ~ fs/40 frequency (hz) 1m 10m 100m 1g C18 amplitude (db) C12 C6 0 14071 g21 C24 C30 C36 6 12 frequency (hz) C80 cmrr (db) C40 0 C100 C60 C20 100 1k 14071 g22 C120 10k 100k 1m 10m 100m ch0 ch1 frequency (hz) C70 crosstalk (db) C50 C20 C80 C60 C40 C30 100 1k 10k 100k 1m 10m 14071 g23 C90 ch0 to ch1 ch1 to ch0 time (ns) C5 output code 6144 8192 10240 10 20 14071 g24 4096 2048 0 05 15 12288 14336 16384 25 ch0 and ch1 rising ch0 ch1 ch0 and ch1 falling frequency (hz) 110 C50 psrr (db) C45 C40 C35 C30 100 1k 10k 100k 1m 14071 g25 C55 C60 C65 C70 C25
ltc1407-1/ltc1407a-1 9 14071fb typical performance characteristics ch0 + (pin 1): noninverting channel 0. ch0 + operates fully differentially with respect to ch0 C , with a C1.25v to 1.25v differential swing with respect to ch0 C and a 0 to v dd absolute input range. ch0 C (pin 2): inverting channel 0. ch0 C operates fully differentially with respect to ch0 + , with a 1.25v to C1.25v differential swing with respect to ch0 + and a 0 to v dd absolute input range. v ref (pin 3): 2.5v internal reference. bypass to gnd and a solid analog ground plane with a 10f ceramic capacitor (or 10f tantalum in parallel with 0.1f ceramic). can be overdriven by an external reference voltage 2.55v and v dd . ch1 + (pin 4): noninverting channel 1. ch1 + operates fully differentially with respect to ch1 C , with a C1.25v to 1.25v differential swing with respect to ch1 C and a 0 to v dd absolute input range. ch1 C (pin 5): inverting channel 1. ch1 C operates fully differentially with respect to ch1 + , with a 1.25v to C1.25v differential swing with respect to ch1 + and a 0 to v dd absolute input range. gnd (pins 6, 11): ground and exposed pad. this single ground pin and the exposed pad must be tied directly to the solid ground plane under the part. keep in mind that analog signal currents and digital output signal currents ? ow through these connections. v dd (pin 7): 3v positive supply. this single power pin supplies 3v to the entire chip. bypass to gnd pin and solid analog ground plane with a 10f ceramic capacitor (or 10f tantalum) in parallel with 0.1f ceramic. keep in mind that internal analog currents and digital output signal currents ? ow through this pin. care should be taken to place the 0.1f bypass capacitor as close to pins 6 and 7 as possible. sdo (pin 8): three-state serial data output. each pair of output data words represent the two analog input channels at the start of the previous conversion. the output format is 2s complement. sck (pin 9): external clock input. advances the conver- sion process and sequences the output data on the rising edge. one or more pulses wake from sleep. conv (pin 10): convert start. holds the two analog input signals and starts the conversion on the rising edge. two pulses with sck in ? xed high or ? xed low state starts nap mode. four or more pulses with sck in ? xed high or ? xed low state starts sleep mode. v dd = 3v, t a = 25c (ltc1407-1/ltc1407a-1) reference voltage vs v dd reference voltage vs load current pin functions v dd (v) 2.4890 v ref (v) 2.4894 2.4898 2.4902 2.4892 2.4896 2.4900 2.8 3.0 3.2 3.4 14071 g26 2.6 3.6 load current (ma) 0.4 0.8 1.2 1.6 14071 g27 2.0 0.2 0 0.6 1.0 1.4 1.8 2.4890 v ref (v) 2.4894 2.4898 2.4902 2.4892 2.4896 2.4900
ltc1407-1/ltc1407a-1 10 14071fb block diagram C + 1 2 7 3 6 s & h C + 4 5 s & h gnd 11 exposed pad v ref 10f ch0 C ch0 + ch1 C ch1 + 3v 10f ltc1407a-1 8 10 9 three- state serial output port mux 2.5v reference timing logic v dd sdo conv sck 1407a1 bd 3msps 14-bit adc 14-bit latch 14-bit latch
ltc1407-1/ltc1407a-1 11 14071fb timing diagrams sck conv internal s/h status sdo *bits marked x after d0 should be ignored t 7 t 3 t 1 1 34 33 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 21 20 22 23 24 25 26 27 28 29 30 31 32 33 34 1 t 2 t 6 t 8 t 9 t 9 t 8 t 4 t 5 t 8 sample hold hold hold hi-z hi-z hi-z t conv 12-bit data word 12-bit data word sdo represents the analog input from the previous conversion at ch1 t throughput 14071 td01 d11 d10 d8 d7 d6 d5 d4 d3 d2 d1 d0 x* x* d9 d11 d10 d8 d7 d6 d5 d4 d3 d2 d1 d0 x* x* d9 sample t acq sdo represents the analog input from the previous conversion at ch0 sck conv internal s/h status sdo t 7 t 3 t 1 1 34 33 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 21 20 22 23 24 25 26 27 28 29 30 31 32 33 34 1 t 2 t 6 t 8 t 9 t 9 t 8 t 4 t 5 t 8 sample hold hold hold hi-z hi-z hi-z t conv 14-bit data word 14-bit data word sdo represents the analog input from the previous conversion at ch1 t throughput 1407a1 td01 d13 d12 d10 d9 d8 d7 d6 d5 d4 d3 d2 d1 d0 d11 d13 d12 d10 d9 d8 d7 d6 d5 d4 d3 d2 d1 d0 d11 sample t acq sdo represents the analog input from the previous conversion at ch0 ltc1407-1 timing diagram ltc1407a-1 timing diagram
ltc1407-1/ltc1407a-1 12 14071fb timing diagrams nap mode waveforms sck conv nap sck conv nap sleep v ref t 1 t 1 t 12 t 1 note: nap and sleep are internal signals 1407 td02 sleep mode waveforms sck to sdo delay t 8 t 10 sck sdo 14071 td03 v ih v oh v ol t 9 sck sdo v ih 90% 10%
ltc1407-1/ltc1407a-1 13 14071fb applications information driving the analog input the differential analog inputs of the ltc1407-1/ltc1407a-1 are easy to drive. the inputs may be driven differentially or as a single-ended input (i.e., the ch0 C input is ac grounded at v cc /2). all four analog inputs of both differential analog input pairs, ch0 + with ch0 C and ch1 + with ch1 C , are sampled at the same instant. any unwanted signal that is common to both inputs of each input pair will be reduced by the common mode rejection of the sample-and-hold circuit. the inputs draw only one small current spike while charging the sample-and-hold capacitors at the end of conversion. during conversion, the analog inputs draw only a small leakage current. if the source impedance of the driving circuit is low, then the ltc1407-1/ltc1407a-1 inputs can be driven directly. as source impedance increases, so will acquisition time. for minimum acquisition time with high source impedance, a buffer ampli? er must be used. the main requirement is that the ampli? er driving the analog input(s) must settle after the small current spike before the next conversion starts (settling time must be 39ns for full throughput rate). also keep in mind, while choosing an input ampli? er, the amount of noise and harmonic distortion added by the ampli? er. choosing an input amplifier choosing an input ampli? er is easy if a few requirements are taken into consideration. first, to limit the magnitude of the voltage spike seen by the ampli? er from charging the sampling capacitor, choose an ampli? er that has a low output impedance (<100) at the closed-loop bandwidth frequency. for example, if an ampli? er is used in a gain of 1 and has a unity-gain bandwidth of 50mhz, then the output impedance at 50mhz must be less than 100. the second requirement is that the closed-loop bandwidth must be greater than 40mhz to ensure adequate small-signal settling for full throughput rate. if slower op amps are used, more time for settling can be provided by increasing the time between conversions. the best choice for an op amp to drive the ltc1407-1/ltc1407a-1 depends on the application. generally, applications fall into two categories: ac applications where dynamic speci? cations are most critical and time domain applications where dc accuracy and settling time are most critical. the following list is a summary of the op amps that are suitable for driving the ltc1407-1/ltc1407a-1. ltc1566-1: low noise 2.3mhz continuous time low- pass filter. lt ? 1630: dual 30mhz rail-to-rail voltage fb ampli? er. 2.7v to 15v supplies. very high a vol , 500v offset and 520ns settling to 0.5lsb for a 4v swing. thd and noise are C 93db to 40khz and below 1lsb to 320khz (a v = 1, 2v p-p into 1k, v s = 5v), making the part excellent for ac applications (to 1/3 nyquist) where rail-to-rail perfor- mance is desired. quad version is available as lt1631. lt1632: dual 45mhz rail-to-rail voltage fb ampli? er. 2.7v to 15v supplies. very high a vol , 1.5mv offset and 400ns settling to 0.5lsb for a 4v swing. it is suitable for applications with a single 5v supply. thd and noise are C 93db to 40khz and below 1lsb to 800khz (a v = 1, 2v p-p into 1k, v s = 5v), making the part excellent for ac applications where rail-to-rail performance is desired. quad version is available as lt1633. lt1801: 80mhz gbwp , C75dbc at 500khz, 2ma/ampli- ? er, 8.5nv/ hz . lt1806/lt1807: 325mhz gbwp , C80dbc distortion at 5mhz, unity-gain stable, rail-to-rail in and out, 10ma/am- pli? er, 3.5nv/ hz . lt1810: 180mhz gbwp , C90dbc distortion at 5mhz, unity-gain stable, rail-to-rail in and out, 15ma/ampli? er, 16nv/ hz . linearview is a trademark of linear technology corporation.
ltc1407-1/ltc1407a-1 14 14071fb applications information lt1818/lt1819: 400mhz, 2500v/s, 9ma, single/dual voltage mode operational ampli? er. lt6200: 165mhz gbwp , C85dbc distortion at 1mhz, unity-gain stable, rail-to-rail in and out, 15ma/ampli? er, 0.95nv/ hz . lt6203: 100mhz gbwp , C80dbc distortion at 1mhz, unity-gain stable, rail-to-rail in and out, 3ma/ampli? er, 1.9nv/ hz . lt6600: ampli? er/filter differential in/out with 10mhz cutoff. input filtering and source impedance the noise and the distortion of the input ampli? er and other circuitry must be considered since they will add to the ltc1407-1/ltc1407a-1 noise and distortion. the small-signal bandwidth of the sample-and-hold circuit is 50mhz. any noise or distortion products that are pres- ent at the analog inputs will be summed over this entire bandwidth. noisy input circuitry should be ? ltered prior to the analog inputs to minimize noise. a simple 1-pole rc ? lter is suf? cient for many applications. for example, figure 1 shows a 47pf capacitor from cho + to ground and a 51 source resistor to limit the net input bandwidth to 30mhz. the 47pf capacitor also acts as a charge reservoir for the input sample-and-hold and isolates the adc input from sampling-glitch sensitive circuitry. high quality capacitors and resistors should be used since these figure 1. rc input filter components can add distortion. npo and silvermica type dielectric capacitors have excellent linearity. carbon surface mount resistors can generate distortion from self heating and from damage that may occur during soldering. metal ? lm surface mount resistors are much less susceptible to both problems. when high amplitude unwanted signals are close in frequency to the desired signal frequency a multiple pole ? lter is required. high external source resistance, combined with 13pf of input capacitance, will reduce the rated 50mhz input bandwidth and increase acquisition time beyond 39ns. input range the analog inputs of the ltc1407-1/ltc1407a-1 may be driven fully differentially with a single supply. either input may swing up to 3v, provided the differential swing is no greater than 1.25v. in the valid input range, each input of each channel is always up to 1.25v away from the other input of each channel. the C1.25v to 1.25v range is also ideally suited for ac-coupled signals in single supply applications. figure 2 shows how to ac-couple signals in a single supply system without needing a mid-supply 1.5v dc external reference. the dc common mode level is supplied by the previous stage that is already bounded by single supply voltage of the system. the common mode range of the inputs extends from ground to the supply voltage v dd . if the difference between the ch0 + and ch0 C inputs or the ch1 + and ch1 C inputs exceeds 1.25v, the output code will stay ? xed at zero and all ones, and if this difference goes below C1.25v, the output code will stay ? xed at one and all zeros. figure 2. ac coupling of ac signals with 1khz low cut ltc1407-1/ ltc1407a-1 ch0 + ch0 C v ref gnd 14071 f01 1 2 11 3 10 f 47pf* 51* ch1 + ch1 C 4 5 47pf* *tight tolerance required to avoid aperture skew degradation 51* analog input analog input v cm 1.5v dc v cm 1.5v dc + cho + 4.09v c4 10 f 14071 f02 r2 1.6k c2 1 f c1 1 f c1, c2: film type c3: cog type c4: ceramic bypass r1 1.6k 1 2 3 ltc1407-1/ ltc1407a-1 cho C v ref r3 51 c3 56pf v in
ltc1407-1/ltc1407a-1 15 14071fb applications information internal reference the ltc1407-1/ltc1407a-1 have an on-chip, temperature compensated, bandgap reference that is factory trimmed near 2.5v to obtain a precise 1.25v input span. the ref- erence ampli? er output v ref , (pin 3) must be bypassed with a capacitor to ground. the reference amplifier is stable with capacitors of 1f or greater. for the best noise performance, a 10f ceramic or a 10f tantalum in paral- lel with a 0.1f ceramic is recommended. the v ref pin can be overdriven with an external reference as shown in figure 3. the voltage of the external reference must be higher than the 2.5v of the open-drain p-channel output of the internal reference. the recommended range for an external reference is 2.55v to v dd . an external reference at 2.55v will see a dc quiescent load of 0.75ma and as much as 3ma during conversion. errors (dnl) are largely independent of the common mode voltage. however, the offset error will vary. cmrr is typically better than 60db. figure 5 shows the ideal input/output characteristics for the ltc1407-1/ltc1407a-1. the code transitions occur midway between successive integer lsb values (i.e., 0.5lsb, 1.5lsb, 2.5lsb, fs C 1.5lsb). the output code is 2s complement with 1lsb = 2.5v/16384 = 153v for the ltc1407a-1 and 1lsb = 2.5v/4096 = 610v for the ltc1407-1. the ltc1407a-1 has 1lsb rms of gaussian white noise. figure 6a shows the ltc1819 converting a single-ended input signal to differential input signals for optimum thd and sfdr performance as shown in the fft plot (figure 6b). figure 4. cmrr vs frequency figure 3 input span versus reference voltage the differential input range has a unipolar voltage span that equals the difference between the voltage at the reference buffer output v ref (pin 3) and the voltage at the exposed pad ground. the differential input range of adc is C1.25v to 1.25v when using the internal reference. the internal adc is referenced to these two nodes. this relationship also holds true with an external reference. differential inputs the adc will always convert the bipolar difference of ch0 + minus ch0 C or the bipolar difference of ch1 + minus ch1 C , independent of the common mode voltage at either set of inputs. the common mode rejection holds up at high frequencies (see figure 4). the only requirement is that both inputs not go below ground or exceed v dd . integral nonlinearity errors (inl) and differential nonlinearity ltc1407-1/ ltc1407a-1 v ref gnd 14071 f02 3 11 10f 3v ref figure 5. ltc1407-1/ltc1407a-1 transfer characteristic frequency (hz) C80 cmrr (db) C40 0 C100 C60 C20 100 1k 14071 f04 C120 10k 100k 1m 10m 100m ch0 ch1 input voltage (v) 2s complement output code 14071 f05 011...111 011...110 011...101 100...000 100...001 100...010 fs C 1lsb Cfs
ltc1407-1/ltc1407a-1 16 14071fb applications information board layout and bypassing wire wrap boards are not recommended for high resolu- tion and/or high speed a/d converters. to obtain the best performance from the ltc1407-1/ltc1407a-1, a printed circuit board with ground plane is required. layout for the printed circuit board should ensure that digital and analog signal lines are separated as much as possible. in particular, care should be taken not to run any digital track alongside an analog signal track. if optimum phase match between the inputs is desired, the length of the four input wires of the two input channels should be kept matched. but each pair of input wires to the two input channels should be kept separated by a ground trace to avoid high frequency crosstalk between channels. high quality tantalum and ceramic bypass capacitors should be used at the v dd and v ref pins as shown in the block diagram on the ? rst page of this data sheet. for optimum performance, a 10f surface mount tantalum capacitor with a 0.1f ceramic is recommended for the v dd and v ref pins. alternatively, 10f ceramic chip capacitors such as x5r or x7r may be used. the capacitors must be located as close to the pins as possible. the traces con- necting the pins and the bypass capacitors must be kept short and should be made as wide as possible. the v dd bypass capacitor returns to gnd (pin 6) and the v ref by- pass capacitor returns to the exposed pad ground (pin 11). care should be taken to place the 0.1f v dd bypass ca- pacitor as close to pins 6 and 7 as possible. figure 7 shows the recommended system ground connec- tions. all analog circuitry grounds should be terminated figure 6a. the lt1819 driving the ltc1407a-1 differentially figure 6b. ltc1407-1 6mhz sine wave 4096 point fft plot with the lt1819 driving the inputs differentially figure 7. recommended layout Cch0 or Cch1 ltc1407a-1 +ch0 or +ch1 c1 47pf r1 51 c3 1f c5 0.1f 5v C5v c4 1f r5 1k 1.5v cm r3 499 r4 499 r6 1k c2 47pf r2 51 c6 0.1f v in 1.25v p-p max 1407a f06a C + u1 1/2 lt1819 C + u2 1/2 lt1819 frequency (hz) magnitude (db) C60 C30 C20 14031 f06b C70 C80 C120 C100 0 C10 C40 C50 C90 C110 0 371k 185k 556k 741k 1407-1 f07
ltc1407-1/ltc1407a-1 17 14071fb applications information at the ltc1407-1/ltc1407a-1 exposed pad. the ground return from the ltc1407-1/ltc1407a-1 pin 6 to the power supply should be low impedance for noise-free operation. the exposed pad of the 10-lead mse package is also tied to pin 6 and the ltc1407-1/ltc1407a-1 gnd. the exposed pad should be soldered on the pc board to reduce ground connection inductance. digital circuitry grounds must be connected to the digital supply common. power-down modes upon power-up, the ltc1407-1/ltc1407a-1 are initialized to the active state and are ready for conversion. the nap and sleep mode waveforms show the power-down modes for the ltc1407-1/ltc1407a-1. the sck and conv inputs control the power-down modes (see timing diagrams). two rising edges at conv, without any intervening rising edges at sck, put the ltc1407-1/ltc1407a-1 in nap mode and the power drain drops from 14mw to 6mw. the internal reference remains powered in nap mode. one or more rising edges at sck wake up the ltc1407-1/ltc1407a-1 for service very quickly and conv can start an accurate conversion within a clock cycle. four rising edges at conv, without any intervening rising edges at sck, put the ltc1407-1/ltc1407a-1 in sleep mode and the power drain drops from 14mw to 10w. to bring the part out of sleep mode requires one or more rising sck edges followed by a nap request. then one or more rising edges at sck wake up the ltc1407-1/ltc1407a-1 for operation. when nap mode is entered after sleep mode, the reference that was shut down in sleep mode is reactivated. the internal reference (v ref ) takes 2ms to slew and settle with a 10f load. using sleep mode more frequently com- promises the settled accuracy of the internal reference. note that for slower conversion rates, the nap and sleep modes can be used for substantial reductions in power consumption. digital interface the ltc1407-1/ltc1407a-1 have a 3-wire spi (serial protocol interface) interface. the sck and conv inputs and sdo output implement this interface. the sck and conv inputs accept swings from 3v logic and are ttl compatible, if the logic swing does not exceed v dd . a de- tailed description of the three serial port signals follows: conversion start input (conv) the rising edge of conv starts a conversion, but subse- quent rising edges at conv are ignored by the ltc1407-1/ ltc1407a-1 until the following 32 sck rising edges have occurred. the duty cycle of conv can be arbitrarily chosen to be used as a frame sync signal for the processor serial port. a simple approach to generate conv is to create a pulse that is one sck wide to drive the ltc1407-1/ltc1407a-1 and then buffer this signal to drive the frame sync input of the processor serial port. it is good practice to drive the ltc1407-1/ltc1407a-1 conv input ? rst to avoid digital noise interference during the sample-to-hold transition triggered by conv at the start of conversion. it is also good practice to keep the width of the low portion of the conv signal greater than 15ns to avoid introducing glitches in the front end of the adc just before the sample-and-hold goes into hold mode at the rising edge of conv. minimizing jitter on the conv input in high speed applications where high amplitude sinewaves above 100khz are sampled, the conv signal must have as little jitter as possible (10ps or less). the square wave output of a common crystal clock module usually meets this requirement easily. the challenge is to generate a conv signal from this crystal clock without jitter corruption from other digital circuits in the system. a clock divider and any gates in the signal path from the crystal clock to the conv input should not share the same integrated circuit with other parts of the system. as shown in the interface circuit examples, the sck and conv inputs should be driven ? rst, with digital buffers used to drive the serial port interface. also note that the master clock in the dsp may already be corrupted with jitter, even if it comes directly from the dsp crystal. another problem with high speed processor clocks is that they often use a low cost, low speed crystal (i.e., 10mhz) to generate a fast, but jittery, phase-locked-loop system clock (i.e., 40mhz). the jitter in these pll-generated high speed clocks can be several nanoseconds. note that if you choose to use the frame sync signal generated by the dsp port, this signal will have the same jitter of the dsps master clock.
ltc1407-1/ltc1407a-1 18 14071fb applications information serial clock input (sck) the rising edge of sck advances the conversion process and also updates each bit in the sdo data stream. after conv rises, the third rising edge of sck sends out two sets of 12/14 data bits, with the msb sent ? rst. a simple approach is to generate sck to drive the ltc1407-1/ ltc1407a-1 ? rst and then buffer this signal with the appropriate number of inverters to drive the serial clock input of the processor serial port. use the falling edge of the clock to latch data from the serial data output (sdo) into your processor serial port. the 14-bit serial data will be received right justi? ed, in two 16-bit words with 32 or more clocks per frame sync. it is good practice to drive the ltc1407-1/ltc1407a-1 sck input ? rst to avoid digi- tal noise interference during the internal bit comparison decision by the internal high speed comparator. unlike the conv input, the sck input is not sensitive to jitter because the input signal is already sampled and held constant. serial data output (sdo) upon power-up, the sdo output is automatically reset to the high impedance state. the sdo output remains in high impedance until a new conversion is started. sdo sends out two sets of 12/14 bits in 2s complement format in the output data stream after the third rising edge of sck after the start of conversion with the rising edge of conv. the two 12-/14-bit words are separated by two clock cycles in high impedance mode. please note the delay speci? cation from sck to a valid sdo. sdo is always guaranteed to be valid by the next rising edge of sck. the 32-bit output data stream is compatible with the 16-bit or 32-bit serial port of most processors. hardware interface to tms320c54x the ltc1407-1/ltc1407a-1 are serial output adcs whose interface has been designed for high speed buff- ered serial ports in fast digital signal processors (dsps). figure 8 shows an example of this interface using a tms320c54x. the buffered serial port in the tms320c54x has direct access to a 2kb segment of memory. the adcs serial data can be collected in two alternating 1kb segments, in real time, at the full 3msps conversion rate of the ltc1407-1/ltc1407a-1. the dsp assembly code sets frame sync mode at the bfsr pin to accept an external positive going pulse and the serial clock at the bclkr pin to accept an external positive edge clock. buffers near the ltc1407-1/ltc1407a-1 may be added to drive long tracks to the dsp to prevent corruption of the signal to ltc1407-1/ltc1407a-1. this con? guration is adequate to traverse a typical system board, but source resistors at the buffer outputs and termination resistors at the dsp , may be needed to match the characteristic impedance of very long transmission lines. if you need to terminate the sdo transmission line, buffer it ? rst with one or two 74acxx gates. the ttl threshold inputs of the dsp port respond properly to the 3v swing used with the ltc1407-1/ ltc1407a-1. figure 8. dsp serial interface to tms320c54x 14071 f08 7 10 9 8 6 3-wire serial interfacelink v dd conv sck ltc1407-1/ ltc1407a-1 sdo v cc bfsr bclkr tms320c54x bdr gnd conv 0v to 3v logic swing clk 5v 3v b13 b12
ltc1407-1/ltc1407a-1 19 14071fb applications information ; 12-03-03 ****************************************************************** ; files: 014siab.asm -> 1407a sine wave collection with serial port interface ; bvectors.asm both channels collected in sequence in the same 2k record. ; s2k14ini.asm buffered mode 2k buffer size. ; first element at 1024, last element at 1023, two middles at 2047 and 0000 ; bipolar mode ; works 16 or 64 clock frames. ; negative edge bclkr ; negative bfsr pulse ; -0 data shifted ; *************************************************************************** .width 160 .length 110 .title ?sineb0 bsp in auto buffer mode? .mmregs .setsect ?.text?, 0x500,0 ;set address of executable .setsect ?vectors?, 0x180,0 ;set address of incoming 1403 data .setsect ?buffer?, 0x800,0 ;set address of bsp buffer for clearing .setsect ?result?, 0x1800,0 ;set address of result for clearing .text ;.text marks start of code start: ;this label seems necessary ;make sure /pwrdwn is low at j1-9 ;to turn off ac01 adc tim=#0fh prd=#0fh tcr = #10h ; stop timer tspc = #0h ; stop tdm serial port to ac01 pmst = #01a0h ; set up iptr. processor mode status register sp = #0700h ; init stack pointer. dp = #0 ; data page ar2 = #1800h ; pointer to computed receive buffer. ar3 = #0800h ; pointer to buffered serial port receive buffer ar4 = #0h ; reset record counter call sineinit ; double clutch the initialization to insure a proper sinepeek: call sineinit ; reset. the external frame sync must occur 2.5 clocks ; or more after the port comes out of reset. wait goto wait ; ???????? buffered receive interrupt routine ????????? breceive: ifr = #10h ; clear interrupt ags tc = bitf(@bspce,#4000h) ; check which half (bspce(bit14)) of buffer if (ntc) goto bufull ; if this still the rst half get next half bspce = #(2023h + 08000h); turn on halt for second half (bspce(bit15)) return_enable
ltc1407-1/ltc1407a-1 20 14071fb applications information ; ??????? mask and shift input data ?????????????? bufull: b = *ar3+ << -0 ; load acc b with bsp buffer and shift right -0 b = #07fffh & b ; mask out the tristate bits with #03fffh b = b ^ #2000h ; invert the msb for bipolar operation ; *ar2+ = data(#0bh) ; store b to out buffer and advance ar2 pointer tc = (@ar2 == #02000h) ; output buffer is 2k starting at 1800h if (tc) goto start ; restart if out buffer is at 1fffh goto bufull ; ????????? dummy bsend return ???????????? bsend return_enable ;this is also a dummy return to de ne bsend ;in vector table le bvectors.asm ; ??????????? end isr ?????????????? .copy ?c:\dskplus\1403\s2k14ini.asm? ;initialize buffered serial port .space 16*32 ;clear a chunk at the end to mark the end ;====================================================================== ; ; vectors ; ;====================================================================== .sect ?vectors? ;the vectors start here .copy ?c:\dskplus\1403\bvectors.asm? ;get bsp vectors .sect ?buffer? ;set address of bsp buffer for clearing .space 16*0x800 .sect ?result? ;set address of result for clearing .space 16*0x800 .end ; *************************************************************************** ; file: bvectors.asm -> vector table for the ?c54x dskplus 10.jul.96 ; bsp vectors and debugger vectors ; tdm vectors just return ; *************************************************************************** ; the vectors in this table can be con gured for processing external and ; internal software interrupts. the dskplus debugger uses four interrupt ; vectors. these are reset, trap2, int2, and hpiint. ; * do not modify these four vectors if you plan to use the debugger * ; ; all other vector locations are free to use. when programming always be sure ; the hpiint bit is unmasked (imr=200h) to allow the communications kernel and ; host pc interact. int2 should normally be masked (imr(bit 2) = 0) so that the ; dsp will not interrupt itself during a hint. hint is tied to int2 externally. ; ; ;
ltc1407-1/ltc1407a-1 21 14071fb applications information .title ?vector table? .mmregs reset goto #80h ;00; reset * do not modify if using debugger * nop nop nmi return_enable ;04; non-maskable external interrupt nop nop nop trap2 goto #88h ;08; trap2 * do not modify if using debugger * nop nop .space 52*16 ;0c-3f: vectors for software interrupts 18-30 int0 return_enable ;40; external interrupt int0 nop nop nop int1 return_enable ;44; external interrupt int1 nop nop nop int2 return_enable ;48; external interrupt int2 nop nop nop tint return_enable ;4c; internal timer interrupt nop nop nop brint goto breceive ;50; bsp receive interrupt nop nop nop bxint goto bsend ;54; bsp transmit interrupt nop nop nop trint return_enable ;58; tdm receive interrupt nop nop nop txint return_enable ;5c; tdm transmit interrupt nop nop int3 return_enable ;60; external interrupt int3 nop nop nop hpiint dgoto #0e4h ;64; hpiint * do not modify if using debugger * nop nop
ltc1407-1/ltc1407a-1 22 14071fb applications information .space 24*16 ;68-7f; reserved area ********************************************************************** * (c) copyright texas instruments, inc. 1996 * ********************************************************************** * * * file: s2k14ini.asm bsp initialization code for the ?c54x dskplus * * for use with 1407 in buffered mode * * bspc and spc are the same in the ?c542 * * bspce and spce seem the same in the ?c542 * ********************************************************************** .title ?buffered serial port initialization routine? on .set 1 off .set !on yes .set 1 no .set !yes bit_8 .set 2 bit_10 .set 1 bit_12 .set 3 bit_16 .set 0 go .set 0x80 ********************************************************************** * this is an example of how to initialize the buffered serial port (bsp). * the bsp is initialized to require an external clk and fsx for * operation. the data format is 16-bits, burst mode, with autobuffering * enabled. * ******************************************************************************************* *ltc1407 timing from board with 10mhz crystal. * *10mhz, divided from 40mhz, forced to clkin by 1407 board. * *horizontal scale is 25ns/chr or 100ns period at bclkr * *timing measured at dsp pins. jxx pin labels for jumper cable. * *bfsr pin j1-20 ~~\____/~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\____/ ~~~~~~~~~~~* *bclkr pin j1-14 _/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/~\_/ ~\_/~\_/~* *bdr pin j1-26 _?_?_??_? ltc1407-1/ltc1407a-1 23 14071fb applications information * 2? cable from counter to clk at dut *no right shift is needed to right justify the input data in the main program * *the two msbs should also be masked * ******************************************************************************************* * loopback .set no ;(digital looback mode?) dlb bit format .set bit_16 ;(data format? 16,12,10,8) fo bit intsync .set no ;(internal frame syncs generated?) txm bit intclk .set no ;(internal clks generated?) mcm bit burstmode .set yes ;(if burstmode=no, then continuous) fsm bit clkdiv .set 3 ;(3=default value, 1/4 clockout) pcm_mode .set no ;(turn on pcm mode?) fs_polarity .set yes ;(change polarity)yes=^^^\_/^^^, no=___/^\___ clk_polarity .set no ;(change polarity)for bclkr yes=_/^, no=~\_ frame_ignore .set !yes ;(inverted !yes -ignores frame) xmtautobuf .set no ;(transmit autobuffering) rcvautobuf .set yes ;(receive autobuffering) xmthalt .set no ;(transmit buff halt if xmt buff is full) rcvhalt .set no ;(receive buff halt if rcv buff is full) xmtbufaddr .set 0x800 ;(address of transmit buffer) xmtbufsize .set 0x000 ;(length of transmit buffer) rcvbufaddr .set 0x800 ;(address of receive buffer) rcvbufsize .set 0x800 ;(length of receive buffer)works up to 800 * * see notes in the ?c54x cpu and peripherals reference guide on setting up * valid buffer start and length values. page 9-44 * * ********************************************************************** .eval ((loopback >> 1)|((format & 2)<<1)|(burstmode <<3)|(intclk <<4)|(intsync <<5)) ,spcval .eval ((clkdiv)|(fs_polarity <<5)|(clk_polarity<<6)|((format & 1)<<7)|(frame_ignore<<8)|(pcm_mode<<9)), spceval .eval (spceval|(xmtautobuf<<10)|(xmthalt<<12)|(rcvautobuf<<13)|(rcvhalt<<15)), spceval sineinit: bspc = #spcval ; places buffered serial port in reset ifr = #10h ; clear interrupt ags imr = #210h ; enable hpint,enable brint0 intm = 0 ; all unmasked interrupts are enabled. bspce = #spceval ; programs bspce and abu axr = #xmtbufaddr ; initializes transmit buffer start address bkx = #xmtbufsize ; initializes transmit buffer size arr = #rcvbufaddr ; initializes receive buffer start address bkr = #rcvbufsize ; initializes receive buffer size bspc = #(spcval | go) ; bring buffered serial port out of reset return ;for transmit and receive because go=0xc0
ltc1407-1/ltc1407a-1 24 14071fb package description mse package 10-lead plastic msop (reference ltc dwg # 05-08-1664 rev c) msop (mse) 0908 rev c 0.53 p 0.152 (.021 p .006) seating plane 0.18 (.007) 1.10 (.043) max 0.17 C 0.27 (.007 C .011) typ 0.86 (.034) ref 0.50 (.0197) bsc 12 3 45 4.90 p 0.152 (.193 p .006) 0.497 p 0.076 (.0196 p .003) ref 8 9 10 10 1 7 6 3.00 p 0.102 (.118 p .004) (note 3) 3.00 p 0.102 (.118 p .004) (note 4) note: 1. dimensions in millimeter/(inch) 2. drawing not to scale 3. dimension does not include mold flash, protrusions or gate burrs. mold flash, protrusions or gate burrs shall not exceed 0.152mm (.006") per side 4. dimension does not include interlead flash or protrusions. interlead flash or protrusions shall not exceed 0.152mm (.006") per side 5. lead coplanarity (bottom of leads after forming) shall be 0.102mm (.004") max 0.254 (.010) 0 o C 6 o typ detail a detail a gauge plane 5.23 (.206) min 3.20 C 3.45 (.126 C .136) 0.889 p 0.127 (.035 p .005) recommended solder pad layout 0.305 p 0.038 (.0120 p .0015) typ 2.083 p 0.102 (.082 p .004) 2.794 p 0.102 (.110 p .004) 0.50 (.0197) bsc bottom view of exposed pad option 1.83 p 0.102 (.072 p .004) 2.06 p 0.102 (.081 p .004) 0.1016 p 0.0508 (.004 p .002) detail b detail b corner tail is part of the leadframe feature. for reference only no measurement purpose 0.05 ref 0.29 ref
ltc1407-1/ltc1407a-1 25 14071fb information furnished by linear technology corporation is believed to be accurate and reliable. however, no responsibility is assumed for its use. linear technology corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. revision history rev date description page number b 12/09 update pin con? guration 2 (revision history begins at rev b)
ltc1407-1/ltc1407a-1 26 14071fb linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7417 (408) 432-1900 fax: (408) 434-0507 www.linear.com ? linear technology corporation 2004 lt 0110 rev b ? printed in usa typical application part number description comments adcs ltc1608 16-bit, 500ksps parallel adc 5v supply, 2.5v span, 90db sinad ltc1609 16-bit, 250ksps serial adc 5v con? gurable bipolar/unipolar inputs ltc1403/ltc1403a 12-/14-bit, 2.8msps serial adc 3v, 15mw, unipolar inputs, msop package ltc1403-1/ltc1403a-1 12-/14-bit, 2.8msps serial adc 3v, 15mw, bipolar inputs, msop package ltc1407/ltc1407a 12-/14-bit, 3msps simultaneous sampling adc 3v, 14mw, 2-channel unipolar input range ltc1411 14-bit, 2.5msps parallel adc 5v, selectable spans, 80db sinad ltc1420 12-bit, 10msps parallel adc 5v, selectable spans, 72db sinad ltc1405 12-bit, 5msps parallel adc 5v, selectable spans, 115mw ltc1412 12-bit, 3msps parallel adc 5v supply, 2.5v span, 72db sinad ltc1402 12-bit, 2.2msps serial adc 5v or 5v supply, 4.096v or 2.5v span ltc1864/ltc1865 ltc1864l/ltc1865l 16-bit, 250ksps 1-/2-channel serial adcs 5v or 3v (l-version), micropower, msop package dacs ltc1666/ltc1667 ltc1668 12-/14-/16-bit, 50msps dac 87db sfdr, 20ns settling time ltc1592 16-bit, serial softspan? i out dac 1lsb inl/dnl, software selectable spans references lt1790-2.5 micropower series reference in sot-23 0.05% initial accuracy, 10ppm drift lt1461-2.5 precision voltage reference 0.04% initial accuracy, 3ppm drift lt1460-2.5 micropower series voltage reference 0.10% initial accuracy, 10ppm drift softspan is a trademark of linear technology corporation.

▲Up To Search▲

Price & Availability of LTC1407A-1-15

	To Download LTC1407A-1-15 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .