BQ21040: starting a charge on a full battery

Hiroshi Sato

Expert 2590 points

Part Number: BQ21040

Hello,

Our customer have a question about bq21040 starting a charge on a full battery.
(in the datasheet p.15 8.4.11)

Does /CHG outputs low(ON) when such a condition written in the datasheet ?
Or, is it depend on Vout ?

Thanks and best regards,

Hiro

over 7 years ago

0 ezhao over 7 years ago

TI__Genius 10240 points

Hiro,

Please refer the BQ21040 datasheet 8.3.6 and 8.4.1 on page 13.

Regards,

Eric

0 Hiroshi Sato over 7 years ago in reply to ezhao

Expert 2590 points

Hello Eric-san,

Thank you for your replying.

So, I decided that the /CHG outputs open drain(High) in that case, isn't it ?

Thanks and best regards,

Hiro

0 Bill Johns over 7 years ago in reply to Hiroshi Sato

TI__Guru* 75976 points

Hello Sato-san
The /CHG output is open drain and will be ON(LOW) during 1st charge (Only).
After charge is complete /CHG turns OFF (High ).
Note that during Re-Charger (Refresh Charge) /CHG is OFF.
The above info is in the data sheet sections point out by Eric.

"Or, is it depend on Vout ?" -- Vout (battery voltage) is used to determine if charge starts and what charge mode is used.

0 Hiroshi Sato over 7 years ago in reply to Bill Johns

Expert 2590 points

Hello Bill-san,

Thank you for your explanation, I'll tell that to our customer.

By the way, it would be better to fix the datasheet 8.3.6 ,

because bq21040 does not have PRE-TERM pin, however, it is written about PRE-TERM resistor.

Thanks and best regards,

Hiro

Power management

Power management forum

BQ21040: starting a charge on a full battery