preliminary PS3180 PS3180 smartshunt tm battery monitor rev. a 1 www.powersmart.com copyright powersmart, inc., 2000 features performs all major battery monitoring and reporting functions including: string voltage measurement, precise current measurement and integration, accurate capacity monitoring and integration with precise on-board timebase, temperature measurement in 0.1 c intervals. industry?s highest accuracy battery monitor based on the ps331 smart battery ic: on-chip 14-bit integrating a/d converter, on-chip 8-bit risc microprocessor, powersmart patented, self-learning algorithms and 3-dimensional battery cell models. advanced communications interface using industry standard smbus v1.1 with pec/crc-8 error correction. extremely low power operation: sleep mode: <12 m a typical sample mode: <250 m a typical run mode: <500 m a typical general description the PS3180 smartshunt ? is a completely self- contained advanced battery monitoring and reporting device. the smartshunt ? is a high current, integrated shunt/sense resistor assembly. the module includes powersmart?s smart battery ic and additional circuitry mounted on a high current shunt for simple system integration. the complete module can replace a normal bus-bar or battery cell interconnect. external connections include a communications interface (smbus) which can be easily isolated, an optional external temperature sensor, and a string voltage input. the PS3180 smartshunt ? can be used as a ?non- intelligent sensor? where only current, integrated current (mahr), voltage, and temperature readings are read. at the user?s option, up to 34 standard smart battery data (sbdata) fields can be read. these include capacity calculations which are performed by an on-board cpu and are based on powersmart?s patented, self-learning algorithms and 3-dimensional battery cell models. the complete module operates from 5-18v to easily accommodate small and large cell strings. benefits provides accurate and critical information for increasing fuel economy and lowering emissions for motive applications. reduces monitoring costs for stationary battery backup applications. provides accurate battery state of charge for all applications. provides information for determining state of health. enhances safety by reducing risk of battery overcharging. applications hybrid electric vehicle (hev) batteries deep cycle marine trolling batteries sli for 12v, 24v, and 42v battery systems standby telecommunications battery backup ups battery backup electric vehicle batteries
powersmart PS3180 smartshunt tm data sheet preliminary rev. a 2 www.powersmart.com copyright powersmart, inc., 2000 absolute maximum ratings description symbol min max units supply voltage v dd -v ss 5.0 20.0 v voltage directly at any pin (except v dd ) v pin -0.5 7.0 v temperature under bias t bias -25 +85 c storage temperature (package dependent) t storage -35 +150 c note: these are stress ratings only. stress greater than the listed ratings may cause permanent damage to the device. exposure to absolute maximum ratings for an extended period may affect device reliability. electrical characteristics (t a = -20 c to +85 c, v dd = 12v 10%) description symbol min typ max units dc characteristics supply voltage v dd 5.4 17.0 v current consumption i dd 8 270 600 m a run mode 375 500 600 m a sample mode 190 250 375 m a low-voltage sleep 8 12 15 m a shelf sleep 10 12 18 m a sense resistor voltage input v sense -152 152 mv ntc reference voltage output at temp pin v reft 150 mv dc characteristics - smbus output voltage for 350 m a output current scl, sda 35 mv pull down current at scl, sda i pulldown 0.5 1.0 m a current at scl, sda i lo , i hi 10.0 m a input voltage for low at scl, sda v lo,in -0.5 0.4 0.6 v input voltage for high at scl, sda v hi,in 1.4 2 5.5 v output voltage for low at scl, sda v lo,out 0.2 0.4 v device sink current i sink 100 350 m a ac characteristics - smbus clock operating frequency f smb <1.0 100 khz broadcast bit frequency f smb-mastr 50 f rc /8 68 khz message buffering time t low:sext 24 ms timeout period t timeout 25 35 ms measurement resolution and timing voltage granularity, @max = 17000mv v granularity 16.5 mv/bit temperature granularity, look up tables t granularity 0.1 c/bit current granularity, 25a version, rsense = 1 m w i granularity 18.3 ma/bit current granularity, 100a version, rsense = 0.25 m w i granularity 73.2 ma/bit voltage measurement time, 10 bit v time 45 ms temperature measurement time, 10 bit t time 45 ms current measurement time, 13 bit + sign i time 360 ms module versions powersmart offers the PS3180 as a complete battery monitoring and control module in a variety of standard and semi-custom versions. the PS3180 can be easily customized for a particular application?s battery cell chemistries using the on-board module eeprom. typical cell chemistries are lead-acid (both standby and cycling), nimh, nicd, liion, and lipolymer. upgrades to previously assembled battery units are simple via the standard smbus serial communications interface. the underlying metal shunt resistance can be sized to a particular current range and/or mechanical cell spacing requirement. please contact powersmart for ordering information.
powersmart PS3180 smartshunt tm data sheet preliminary rev. a 3 www.powersmart.com copyright powersmart, inc., 2000 electrical schematic figure 1 shows the electrical schematic of the PS3180. it is divided into two sections: the printed circuit board (pcb) that sits on top of four legs and the baseplate of the unit. electrically, the baseplate operates as a sense resistor that is connected to the pcb through the four legs. u2 is an eeprom. vss 4 si 5 /cs 1 vcc 8 so 2 /hold 7 u2 /wp 3 sck 6 25xx040 ee-sck 2 ee-cs 3 4 vreft 5 vntc smb-clk smb-dta led1 led2 27 26 25 24 u1 vcell1 6 vass 1 7 8 vcell2 9 vcell3 led3 led4 safeout vddd 23 22 21 20 ps331 s vcell4 10 vadd 11 12 vshp 13 vshm ee-si ee-so oscin oscout 19 18 17 16 switch 1 vdss 28 vass 2 14 vreg 15 r3 3.65k, 1% r7 510 ohms r8 510 ohms c7 47 pf c6 47 pf r5 510 ohms r6 510 ohms y1 32768hz j1-2 c2 220 nf r10 4.7meg ohms q1 2n7002 r9 100 ohms c1 220 nf d g s j1-3 j1-4 j3-2 w1 w3 w2 w4 smbus data smbus clock j2-t h j2-t l thermistor thermistor thermistor j3-1 j1-1 thermistor (10k @ 25'c) smartshunt tm pcb current sense shunt baseplate of smartshunt tm load/device most negative battery terminal figure 1. electrical schematic of PS3180.
powersmart PS3180 smartshunt tm data sheet preliminary rev. a 4 www.powersmart.com copyright powersmart, inc., 2000 PS3180 connections figure 2 shows the external circuit connections for the PS3180. the communications connector, j1, provides an smbus data and clock connection as well as power. the power port, connector j3, provides power to the smartshunt ? . an optional thermistor can be used to provide a temperature input for the smartshunt ? . as shown in figure 2, the right side of the smartshunt ? baseplate is connected to the most negative terminal of the battery. the left side of the smartshunt ? is attached to the load or device side, or the next cell string. current ratings and measurements the two initial PS3180 smartshunt ? models have been designed to measure the following ranges of current: 25a version : maximum current of 150 amps with a minimum resolution of 18.2ma (available in 36 and 52mm). 100a version : maximum current of 600 amps with a minimum resolution of 73.2ma. the following paragraphs explain how these values were determined. the maximum input voltage at either vshp or vshm is 150mv (ref. fig. 1). the sense resistor (baseplate of smartshunt ? ) is sized to provide as wide a range of current measurement as required with as small a resolution as possible. since the 14-bit a/d is operated with a resolution of 13-bit plus sign during current measurements, there are 8192 steps in the full measurement range. based on this information, the following equations can be used to select a sense resistor value for a particular maximum current range or minimum resolution. current lsb = 18.3 m v/r sense (m w ) maximum current = current lsb x 8192 for the PS3180, a value of 1m w has been selected for the sense resistor (baseplate) for the 25a version and a value of 0.25m w has been selected for the sense resistor (baseplate) for the 100a version. the current is measured for 360 milliseconds every 500 millisecond period. voltage measurements the a/ d input channel operates in a 10-bit resolution mode for voltage measurements. therefore, there are only 1024 steps in the full voltage measurement range. based on a maximum input range of 17v, the minimum resolution for voltage measurement is 16.5mv per lsb. the voltage is measured for 45 milliseconds every 500 millisecond period. temperature measurements the a/d input channel operates in a 10-bit resolution mode for temperature measurements. the external thermistor should be a standard 10k w at 25 c negative temperature coefficient (ntc) device of the 103etb type for proper operation. a linearization look-up table is used to convert the voltage measurement seen at the vntc pin (ref. fig. 1) to a temperature value. absolute temperature accuracy is 3 c but relative accuracy is better than 1 c. the temperature is measured for 45 milliseconds every 500 millisecond period. calibration the PS3180 smartshunt ? voltage and current readings are calibrated at the factory before shipment. these calibration tests compensate for the offset and gain of the a/d as well as for any minor differences in the actual shunt resistance versus its specified value. it should be noted that the ps331 smart battery ic has an integral auto-offset calibration feature which operates when enabled. this feature corrects for drift in the offset error over temperature during operation. references the ps331 smart battery ic is an integral part of the PS3180 smartshunt ? . the ps331 data sheet, available on powersmart?s website at www.powersmart.com , provides significant detail on the ic?s architecture, operational modes, communications interface, and smart battery data functions. j3 j1 j2 load / device side battery side u1 t h t l c + - d + - w4 w1 w3 w2 thermistor communications power figure 2. external circuit connections
powersmart PS3180 smartshunt tm data sheet preliminary rev. a 5 www.powersmart.com copyright powersmart, inc., 2000 ordering information the table below describes the initially available smartshunt ? models. please contact powersmart for alternate current ranges and mechanical mounting dimensions. part number description PS3180-2536 25a current rating in 36mm length PS3180-2552 25a current rating in 52mm length PS3180-10044 100a current rating in 44mm length mechanical packaging information PS3180-2536: 36mm package, complete assembly dimensions in mm 7.7 36 15.2 22 51.2 7 dia 2x 0.5
powersmart PS3180 smartshunt tm data sheet preliminary rev. a 6 www.powersmart.com copyright powersmart, inc., 2000 PS3180-2552: 52 mm package, baseplate only 15.2 52 67 7 dia 2x dimensions in mm thickness of plate is 0.5 PS3180-10044: 44mm package, baseplate only 15.0 6.55 dia 2x 44 60 dimensions in mm thickness of plate is 2
|
