SC3333 energy metering ic with pulse output sop-16-225-1.27 description the SC3333 is a high accuracy electrical energy measurement ic that can provides superior stability and accuracy over extremes in environmental conditions and over time. the SC3333 does not exhibit any creep when there is no load. the SC3333 supplies average real power information on the low frequency outputs f1 and f2. this logic outputs may be used to directly drive an electromechanicall y counter or interface to an mcu. the cf logic output gives instantane ous real power information. this output is intended to be used for calib ration purposes, or interfacing to an mcu. the SC3333 includes a power supply monitoring circuit on the vdd supply pin. if the supply falls below 4v, the SC3333 will be reset and f1, f2 will be set to logic high, cf will be set to logic low at the same time. the SC3333 provides synchronous frequency output for auto- reading meter system. the cf logic ou tput is synchronous with the f1 and f2 logic output to ensure the show value of the meter is consonant with the real value. ordering information device package SC3333 sop-16-225-1.27 features * single 5v supply, low power. * on-chip power supply monitoring. * on-chip reference with external overdrive capability. * supplies average real power on the frequency outputs f1 and f2, which can drive for electromechanical counters directly. * the high frequency output cf is intended for calib ration and supplies instantaneous real power. * less than 0.1% error over a dynamic range of 500 to 1. * on-chip creep protection (no load threshold). * the logic output revp can be used to indicate a potential miswiring or negative power. * a pga in the current channel make flexible to select the shunt and burden resistance. hangzhou silan microelectronics co.,ltd rev:1.1 2008.04.29 http : www.silan.com.cn page 1 of 8
SC3333 block diagram absolute maximum rating (t amb =25 c, unless otherwise specified) characteristics symbol ratings unit v dd to agnd/dgnd v dd -0.3 ~ +7 v analog input voltage to agnd v 1p , v 1n , v 2p and v 2n av in -6 ~ +6 v reference input voltage to agnd v ref -0.3 ~ v dd +0.3 v digital input voltage to dgnd dv in -0.3 ~ v dd +0.3 v digital output voltage to dgnd dv out -0.3 ~ v dd +0.3 v power dissipation p d 450 mw operating temperature range t opr -40~ +85 c storage temperature t stg -65~ +150 c junction temperature t j +150 c electrical characteristics (t amb =25 c, unless otherwise specified) characteristics symbol test conditions min. typ. max. unit power supply power supply v dd 5v 5% 4.75 -- 5.25 v analog input current ai dd (2ma) typ. -- -- 3 digital input current di dd (1.5ma) typ. -- -- 2.5 ma accuracy gain=1 over a dynamic range 500 to 1 -- 0.1 -- % measurement error 1 on channel 1 gain=16 e m over a dynamic range 500 to 1 -- 0.1 -- % (to be continued) hangzhou silan microelectronics co.,ltd rev:1.1 2008.04.29 http : www.silan.com.cn page 2 of 8
SC3333 hangzhou silan microelectronics co.,ltd rev:1.1 2008.04.29 http : www.silan.com.cn page 3 of 8 (continued) characteristics symbol test conditions min. typ. max. unit v1 phase lead 37 q -- -- r 0.1 q phase error 1 between channels v1 phase lag 60 q e p -- -- -- r 0.1 q output frequency rejection (ac) c fa v 1 =100mv, v 2 =100mv, set=0 -- 0.01 -- % output frequency rejection (dc) c fd v 1 =100mv, v 2 =100mv, v dd =5v r 250mv -- 0.01 -- % analog inputs maximum signal levels levs v 1p , v in v 2n and v 2p to agnd -- -- r 1 v input impedance (dc) i min c lkin =3.58mhz 400 -- -- k : bandwidth (-3db) bw c lkin /256, c lkin =3.58mhz -- 14 -- khz adc offset error 1,2 eadc -- -- 15 mv gain error 1 e g v1=470mv, v2=660mv -- r 4 -- % gain error match 1 e gm external 2.5v reference -- r 0.2 -- % reference input refin/out input voltage range v inr 2.5v r 8% 2.3 -- 2.7 v input impedance i min -- 3.7 -- -- k : input capacitance cin -- -- -- 10 pf on-chip reference reference error e r -- -- 200 mv temperature coefficient t c nominal 2.5v -- 30 60 ppm/ q c clkin input clock frequency c lkin note all specifications for clkin of 3.58mhz 1 -- 4 mhz logic inputs 3 input high voltage v inh v dd =5v r 5% 2.4 -- -- v input low voltage v inl v dd =5v r 5% -- -- 0.8 v input current i in typically 10na, v in =0v to v dd -- -- r 3 p a input capacitance c in -- -- 10 pf logic outputs 3 output high voltage v oh i source =10ma,v dd =5v 4.5 -- -- v f1 and f2 output low voltage v ol i sink =10ma, v dd =5v -- -- 0.5 v output high voltage v oh i source =5ma,v dd =5v 4 -- -- v cf and revp output low voltage v ol i sink =5ma, v dd =5v -- -- 0.5 v
SC3333 pin configuration 1 2 3 4 5 6 7 8 12 11 10 9 16 15 14 13 dgnd v dd agnd set v 1p v 1n v 2p v 2n ref in/out clkin clkout revp cf f1 f2 reset SC3333 pin description pin no. symbol description 1 v dd power supply. 2 v 1p 3 v 1n positive and negative inputs for channel 1 (current channel). channel 1 has a pga and the gain selections are outlined in table i. the maximum signal level at these pins is 1v with respect to agnd. 4 v 2n 5 v 2p negative and positive inputs for channel 2 (voltage channel). the maximum differential input voltage is 660mv for specified operation. the maximum signal level at these pins is 1v with respect to agnd. 6 reset reset pin for the SC3333. a logic low is valid. 7 ref in/out reference voltage input/output pin. 8 agnd analog ground. 9 set channel 1 gain select pin. see table 1. 10 clk in 3.58mhz crystal oscillator input pin. 11 clk out 3.58mhz crystal oscillator output pin. 12 revp state indication pin. while negative power or a potential miswriting occurs, it will be set to logic high. 13 dgnd digital ground. 14 cf calibration fr equency logic output.. 15 f2 16 f1 low frequency logic outputs. they can be used to directly drive a stepper motor or electromechanical impulse counter. hangzhou silan microelectronics co.,ltd rev:1.1 2008.04.29 http : www.silan.com.cn page 4 of 8
SC3333 timiing characteristics 1,2 (v dd =5v 5%, a gnd =d gnd =0v, on-chip reference, c lkin =3.58mhz, t min to t max =-40 c~+85 c.) parameter test condition test data units t1 3 f1 and f2 pulse-width 275 ms t2 f1 and f2 pulse period. tbd sec t3 time between f1 falling edge and f2 falling edge 1/2 t2 sec t4 3 cf pulse-width 90 ms t5 cf pulse period. tbd sec t6 minimum time between f1 and f2 pulse clkin/4 sec note: 1. sample tested during initial release and afte r any redesign or process change that may after this parameter. 2. see the following figure. 3. the pulse-widths of f1, f2 and cf are not fixed for higher output frequencies. timing diagram for frequency outputs timing diagram for frequency outputs shows a timing diagram for the various frequency outputs of the SC3333. the low frequency outputs, f1 and f2 can dr ive electromechanical counters and two phase stepper motors directly. as the figure show, the f1 and f2 out puts provide two alternating low going pulses. the pulse width (t1) is set at 275ms and the time between the falli ng edges of f1 and f2 (t3) is approximately half the period of f1 (t2). if however the period of f1 and f2 falls below 550 ms (1.81hz) the pulse width of f1 and f2 is set to half of their period. the frequency of f1 and f2 corresponds to the input voltages, and f= 13.6*v1*v2*g / vref 2 the values of g can be set by consumers, and the selection of g please refer to the table i , v1 and v2 are the rms value of the two inputs , vref is the voltage of reference, whose value is 2.5 + 0.2v when the internal bandgap reference of SC3333 is valid. the high frequency output, cf is intended for calibrat ion and supplies instantaneous real power. cf produces a 90ms wide active high pulse (t4) at a frequency proportional to active power . as in the case of f1 and f2, if the period of cf (t5) falls below 180ms, the cf pulse-width is set to half the period. appendix table i. gain selection for channel 1 set gain maximum differen tial signal 0 1 470mv 1 16 30mv hangzhou silan microelectronics co.,ltd rev:1.1 2008.04.29 http : www.silan.com.cn page 5 of 8
SC3333 typical application circuit hangzhou silan microelectronics co.,ltd rev:1.1 2008.04.29 http : www.silan.com.cn page 6 of 8
SC3333 package outline sop-16-225-1.27 unit: mm 6.0 0.4 3.9 0.3 5.72 0.25 handling mos devices: electrostatic charges can exist in many things. all of our mos devices are inte rnally protected against electrostatic discharge but they can be damage d if the following precautions are not taken: ? persons at a work bench should be earthed via a wrist strap. ? equipment cases should be earthed. ? all tools used during assembly, including sol dering tools and solder baths, must be earthed. ? mos devices should be packed for dispatch in antistatic/conductive containers. hangzhou silan microelectronics co.,ltd rev:1.1 2008.04.29 http : www.silan.com.cn page 7 of 8
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