Good day,
I have designed a PCB that uses the MAX17320G20+ IC as the BMS for a 4S battery pack. I am having trouble with using the IC.
Note, for all initial tests I used a power supply set to 15V with 4 resistors in series to simulate the independent cells. The first IC was fine when I applied power. Then after jump starting the IC, connecting pack+ to batt, The IC powered up fine and reg3 was outputting 3.4V. I had a ADUM1252ASA+ connected to logic shift the I2C to my MCU, and after a while trying to communicate with the IC, it just suddenly let out some smoke. Reg3 was shorted to ground and the IC was dead. I figured it was because the ADUM1252ASA+ was drawing too much current from the reg3 pin. So I removed it and replace the BMS. I connected the I2C lines directly to the BMS.
This time the IC worked fine and I was able to power it up, connect batteries and all was dandy!
So I decided to do the same for the rest of my PCBs. The first one just immediately blew when trying to jump start it (Reg3 shorted to ground), so I thought it was either soldered incorrectly or it was a faulty IC. I replaced it again and this time it was fine when applying power and jump starting it. But after a while the power supply just tripped and was showing a short circuit, so I measured the resistance between the pins. The resistance between GND and batt and GND and vcell3 is very low, like 30 ohm, so I dont know what went wrong. This time Reg3 was not shorted to ground.
Please find my schematic attached. I look forward to hearing back from you.
Kind regards,
Russouw Grobbelaar
