BQ40Z80: Default status for MOSFET

Songzhen Guo

Part Number: BQ40Z80
Other Parts Discussed in Thread: BQ76930, BQ34Z100-G1

Hi expert,

BQ40Z80 is under evaluating on customer side. Now customer want to know:

When BQ40Z80 is active and it works well. Will it turn off the MOSFET by itself when there is no control signal from MCU?

Could you help us on that? Thanks.

Best Regards

Songzhen Guo

over 4 years ago

0 Kang Kang over 4 years ago

TI__Mastermind 24870 points

Hello Songzhen,

This is due to the watchdog issue we have found on the bq40z80.

Can you let me know if this is a 7S application or 6S?

0 Rushi_Dalal over 4 years ago

TI__Intellectual 2025 points

Hi Songzhen,

If application is 7S, please consider different solution such as BQ34z100-G1 or BQ76930 battery monitor.

Thanks,

Rushi

0 z4ci4n over 4 years ago in reply to Rushi_Dalal

Prodigy 80 points

Hello Rushi,

I have already designed and used my BMS in 7s application. Does the watchdog issue that you mentioned above cause big problems? If yes, how TI thinks to resolve this problem in 7s applications? As you know there are severel people who use this IC to control their 7S batteries.

My second question is about a BMS with MCU. MCU and bq40z80 are communicating in my design. Can I solve this issue with the help of MCU?

Thanks,

0 Rushi_Dalal over 4 years ago in reply to z4ci4n

TI__Intellectual 2025 points

Hi z4ci4n,

This would require an architectural FW change. There is not an MCU work-around. The team will be working a newer firmware to address the watchdog issue.

Thanks,

Rushi

0 Songzhen Guo over 4 years ago in reply to Rushi_Dalal

TI__Intellectual 2840 points

Hi Rushi,

Could you provide the new firmware to customer？

By the way, could you review the schematic and layout? i forward the schematic and layout to you though E-mail. Thanks.

Best Regards

Songzhen Guo

0 Rushi_Dalal over 4 years ago in reply to Songzhen Guo

TI__Intellectual 2025 points

Hi Songzhen,

Unfortunately new firmware is not available at this time. It takes significant development effort and goes through validation as well. It's currently under development. You will have to continue using the FW you currently have for now.

I will check your offline email too.

Thanks,

Rushi

Power management

Power management forum

BQ40Z80: Default status for MOSFET