BQ76940: Measurement voltage problem

tony li61324

Part Number: BQ76940

Hi Tier

1、our produce 200 set BQ7694003 find 15 set difference between the reading voltage and the actual voltage is very large.

Dismantling BQ7694003 form PCB ，test pin already short circuited,such as cell 11 and cell 12 measurement volatile is 50mV and 5000mv （actual voltage is 3.3v）, the Pin 28 and pin 29 short .

Would you please help advise what’s reason for the damage？ thanks！

over 8 years ago

0 bdefar over 8 years ago

TI__Prodigy 680 points

Hi Tony,
One of our BMS experts has been assigned to your issue and will answer shortly.

0 WM5295 over 7 years ago

TI__Guru 54715 points

Hi Tony,
The most likely cause of a short from pins 28 to 29 would be a high voltage applied to the pins. You will need to find the issue in your situation. One possibility may be the figure 21 of www.ti.com/.../slua749a.pdf. You may find a procedure to limit voltage or you may need to design in a protection for the part limit.

0 tony li61324 over 7 years ago in reply to WM5295

Intellectual 500 points

Thanks for your answer！

Random Cell Connection whether can damage pins？

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BQ76940: Measurement voltage problem