BQ40Z60: Charging MOSFET failue and SMBUS Intermittency Communication issues during charging.

Robert Creighton

Part Number: BQ40Z60

We are encountering Charging MOSFET failures, elevated heat on the BQ chip during charging and intermittent SMBUS Communications issues with our design using the BQ40Z60 that follows the TI reference design. Does TI offer a design/schematic review/assessment to ensure the TI chips are implemented into the design appropriately? We have data logs and SREC files to share.

over 4 years ago

0 Andy Liu (BMS) over 4 years ago

TI__Guru 52115 points

Hi Robert,

We can take a look at your schemaic. Can you share the schematic with us? Thanks.

Andy

0 Robert Creighton over 4 years ago in reply to Andy Liu (BMS)

Prodigy 40 points

Is there a way to attach files for review OR do you want me to paste them into this form?

0 Robert Creighton over 4 years ago in reply to Andy Liu (BMS)

Prodigy 40 points

Thanks Andy - Please find the files attached

DM4122DT.SCH.pdf

.DM4122DTV2 BOM NEW.xls

0 Robert Creighton over 4 years ago in reply to Andy Liu (BMS)

Prodigy 40 points

Andy - Do you have feedback?

0 Andy Liu (BMS) over 4 years ago in reply to Robert Creighton

TI__Guru 52115 points

Hi Robert,

I have been quite busy this week. I will try to review your schematic and provide my feedback by Friday.

Andy

0 Andy Liu (BMS) over 4 years ago in reply to Andy Liu (BMS)

TI__Guru 52115 points

Hi Robert,

Sorry for my late response. See my comments below.

a) Check R23, R24, R25, and R26. Their connections are not correct. I would suggest you take a closer look at the EVM schematic and fix these connections.

b) I cannot find the resistance of R11. I would suggest you take a look at the following app note and see how these feedback resistors affect the output voltage.

http://www.ti.com.cn/cn/lit/an/slua750/slua750.pdf

Andy

Power management

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BQ40Z60: Charging MOSFET failue and SMBUS Intermittency Communication issues during charging.