BQ40Z80: BQ40Z80: PACK pin relation to wake-up/shutdown of chip

WeiMeng Ooi

Part Number: BQ40Z80

Hi,

I have question related to the use of PACK pin to recover from Shut down mode. I am designing a button circuit to pass the Battery (Cell) voltage to PACK pin to recover from shut-down. However, I need to isolate my circuit from the main discharge output. Can I have a series diode to the 10kOhm resistor to PACK+ pin as shown below:

Thanks

over 1 year ago

0 Anthony over 1 year ago

TI__Mastermind 28480 points

Hello,

This button is implemented on our bq40z80EVM. The document below includes the schematic on page 23 for your reference of how our team implemented this feature.

https://www.ti.com/lit/pdf/sluubz5

In the image above, the "7P" connection is to the BAT pin.

Regards,

Anthony Baldino

0 WeiMeng Ooi over 1 year ago in reply to Anthony

Prodigy 30 points

Hi,

I saw the implementation on the EVM, but I need to some modification as I mentioned in the previous post. I need to know is it ok to add the series diode in series to the 10kOhm resistor to feed the PACK pin. Detail schematic is shown below:

0 Anthony over 1 year ago in reply to WeiMeng Ooi

TI__Mastermind 28480 points

Hello,

I believe the addition of this diode should be ok, there will be a slight drop in voltage at the PACK pin due to this diode I believe but it should be functional.

Regards,

Anthony Baldino

Power management

Power management forum

BQ40Z80: BQ40Z80: PACK pin relation to wake-up/shutdown of chip