Hi team,
Here's an issue from the customer may need your help:
This project is a 4-series battery. When measuring the SMBUS voltage to DIG_GND, it was found that SMBUS was normal 0V to DIG_GND when all 4 cells were in the machine. SMBUS is -5 V for DIG_GND when removing one battery and only 3 cells are placed in the battery, which is a negative voltage that causes damage to the conversion chip in the following figure.
The customer's understanding is as follows:
The BQ73850 does not work properly when the battery is less than one cell, so DSG_EN is not turned on. Ana_GND and DIG_GND are open states, but the MOS tube causes the GND on both sides to be connected, with a negative state. Is that correct?
Issues:
1) Is there a problem with the configuration of the BQ73850?
2) how to resolve the negative voltage issue between two GND?
3) Shorting ANA_GND and DIG_GND directly can solve the negative voltage issue, is it proper to import directly?
Could you help check this case? Thanks.
Best Regards,
Cherry
