BQ76PL455A-Q1: IC functionality query

kishor jayaram

Part Number: BQ76PL455A-Q1
Other Parts Discussed in Thread: BQ76PL455-Q1, BQ76PL455A

HI,

I have designed a Battery management system using BQ76PL455-Q1 IC (Passive balancing method) . The IC was working fine communicating with the host controller for around 15-20 days but all of a sudden it stopped working.

attached is the schematic. voltage at VP, and VDIG pin is found to be 1.02V, V5VAO is showing 5V.

My question is,

1) Do we have any way to check whether the ic is damaged or not?

2) If damaged what are the possibility that the IC gets damaged

bq76pl455a-q1.pdf

over 8 years ago

0 David Wiest Jr over 8 years ago

TI__Genius 11480 points

Kishor,

Did you follow this schematic, or the EVM schematic?

The schematic you provided lacks protection on the Vsense pins. We recommend a low pass filter and a zener clamp on each sense pin. Without those, it is very likely that the part was damaged during hot plug of the cells. TIDA-00717 (Link: www.ti.com/.../tida-00717) has the bq76pl455 EVM schematic.

0 kishor jayaram over 8 years ago in reply to David Wiest Jr

Prodigy 130 points

thank you for the reply, I had included rc filters and zener clamps for vsense pins. Actually i had followed the the EVM schematic itself but i sent the simpler version of the schematic in the earlier attachment.
Regards
kishor

bq76pl455.pdf

0 David Wiest Jr over 8 years ago in reply to kishor jayaram

TI__Genius 11480 points

Kishor,

Do you mind sharing your schematic, and I can look for things that may be potentially incorrect? If you'd like, you can share privately with d-wiest@ti.com...

What values did you use for R and C in the filter? Also, would you mind sharing the part number for the zener clamp?

0 kishor jayaram over 8 years ago in reply to David Wiest Jr

Prodigy 130 points

David,
I have sent you the schematic through private mail.
The following are the values used for RC filter circuit
R: 1k
C: 0.1uF
zener clamp part no: BZT52C6V2

Regards,
kishor

Power management

Power management forum

BQ76PL455A-Q1: IC functionality query