BQ40Z80: Parallel FETs operation

Hi Kim,

Where did you get that diagram? Is it from our documentation or something you created?

Best,

Jessica

Hi Jessica,

I got the diagram (slide 24) from the TI training website as below.

https://training.ti.com/sites/default/files/docs/advanced_topics_on_the_bq40z80_2sto7s.pdf

Please advise how to exit from SHUTDOWN mode to NORMAL mode as PAC_D is connected to load and PACK_C is connected to charger for parallel FET operation.

Thanks,

Kim

Hi Kim,

I reached out to one of my coworkers with more experience with this configuration. I will let you know what they say when I receive a response.

Best,

Jessica

Hi Jessica,

Any update?

Thanks!

Hi Kim,

You could try temporarily shorting PACK_C and PACK_D together with a switch. If that is not an option,  I think applying a voltage to PACK_C would power up the gauge from secondary power supply VCC then FW would execute and check BAT voltage and protections then close the FETs. Either way, you may need to lower the "charger present threshold" data flash value because it may prematurely send the gauge into shutdown and prevent exit of shutdown if the voltage on PACK pin is lower than this threshold.

From what I've seen, I do not believe this is a commonly used configuration.

Best,

Jessica