Other Parts Discussed in Thread: TPS6594-Q1
Dear expert,
Customer system is TPS65941213+LP8764+TDA4.
They report 3pcs high temp shutdown issue among 15Ku manufacture boards.
At 85C air temp, TPS65941213-Q1 and LP8764-Q1 Tj is around 110C~120C. After sometime running at high temp, then randomly, these 3 system all PMIC power output shutdown to 0V. After problem happen, they read PMIC registers. TPS65941213-Q1 registers are all 0. LP8764-Q1 registers can be read back normally. There is OV bit set. Then they disable LP8764-Q1 OV setting, the problem won't happen any more at high temp.
But we cannot see any abnormal with scope for 3.3V input for LP8764-Q1.
Then we cut off on board 3.3V and use an external power supply(out of high temp chamber) for 3.3V input for LP8764-Q1, the phenomenon still can be reproduced.
ABA swap test is done. The phenomenon follows specific LP8764.
Do you have any suggestion for this critical issue?
Thanks