Part Number: BQ40Z50-R3-DEVICE-FW
1. Why are voltage calibrations needed? (Applied Cell 1 voltage, Applied Battery Voltage, and Applied Pack Voltage) as shown on Figure 5 on page 7 of the EVM's manual (https://www.ti.com/lit/ug/sluuav7b/sluuav7b.pdf).
2. Is the IC calibrated at the factory, or does it rely on these customer/user calibrations for its overall accuracy?
3. Is primary the intent of the voltage calibrations to compensate for the effect bleeder external equalizer drive resistors (1KΩ) that attach the VC1...VC4 pins to the cells' terminals shown on bq40z50_External_Cell_Balancing.pdf bq40z50_External_Cell_Balancing.pdf as well as the 10KΩ resistor that attaches the Pack pin to the pack's positive output? Given that that the aforementioned pins have a maximum (across temperature) leakage (ILKG) of 1µA it doesn't seem to be thus worthwhile to calibrate for VC1...VC4 and Pack pins as it would introduce an error of respectively only 1mV and 10mV worst case across temperature
4. Is it advisable to make a "golden" image from calibrating a single specimen and use it to Flash all the other specimens from it? Can the golden image be loaded to all other units or should they be individually calibrated? This includes the current sense resistor calibration as well. Note however that in our application thermistor calibrations are not needed as fixed 10KΩ, 0.1% resistors are used as dummies.
