BQ40Z50-R3-DEVICE-FW: Way to Detect Time-Based Shutdown

Eric Castle

Part Number: BQ40Z50-R3-DEVICE-FW

With this part, it can be configured to go into SHUTDOWN mode based on an extended period of time in SLEEP mode. Is there a way (externally) to tell when this has occurred? I would like other parts in our application to also shutdown when this timeout happens (like having one of the GPIO pins go low or something).

Only idea I have so far is trying to take advantage of the GPIO pins going High-Z when the BQ is in shutdown. I could have the GQ generally actively driving a GPIO line to 0, with a weak pull-up on the line that would cause it to go high once the BQ goes into shutdown.

Any other ideas? If not, any obvious bits I could select that would always have the same value?

Thanks,

-Eric

over 3 years ago

0 Eric Castle over 3 years ago

Intellectual 710 points

Alternatively, is there a way to tell if the BQ is in RELAX mode? I just see a way to see if it is in RELAX OR DISCHARGE.

+1 Wyatt Keller over 3 years ago in reply to Eric Castle

TI__Guru** 105600 points

Hello Eric,

There's not a good way to determine when the gauge goes into shutdown without measuring the current draw. The switch to High-Z state may also be a good detection method if your host can detect this.

The REST bit can be used to determine if you're in relax mode and the gauge has taken an OCV, there's not a direct bit that indicates the entrance into relax mode.

Sincerely,

Wyatt Keller

0 Eric Castle over 3 years ago in reply to Wyatt Keller

Intellectual 710 points

Wyatt,

Oh well, thanks for confirming that.

-Eric

Power management

Power management forum

BQ40Z50-R3-DEVICE-FW: Way to Detect Time-Based Shutdown