Hi,
I manufactured and desigened battery package in BQ29209.
In the production process, found 3 pcs BQ29029 was broke down.
No matter what the battery voltage(Cell2 or Cell1) is high, the pin 3(VC1_CB) always output 0.2V, then Q2 is breakover, cell1 discharge by RCB_EXT. Cross the BQ29209 on the issue board and the normal board, the fault following issue chip. So I judged the chip pin 3 was damaged.
Could you help me, What is the failure reasons of the chip? Are there any hidden peril in schematic?
By the way, the PCBA encapsulated into the battery package after testing, and battery package placed some days, the issue appeared in the test battery package again.