BQ2970: 0V battery charge function, which is "available" and which "anavailable" part references ?

user3985960

Part Number: BQ2970

Hello,

0V battery charge disallowed or Allowed can be seen in the datasheet of BQ2970. In addition, we can seen also in the same datasheet the words "available" and "unavailable" for this function.

My question is, which references of the BQ2970x family are with 0V battery charge "avaible" and "unavailable" function. It is not clear in the datasheet.

Indeed, some battery protections IC manufacturers separate the chip with 0V battery charge "available" and the 0V battery charge "unavailable" but it is not the case of texas instrument.

Thank you in advance.

Best Regards,

Arnaud R.

over 7 years ago

0 Kang Kang over 7 years ago

TI__Mastermind 24870 points

Hello Arnaud,

From the DS, all device families have zero volt charging.

0 user3985960 over 7 years ago in reply to Kang Kang

Prodigy 30 points

Hello Kang,

Thank you for your response.

In the case of 0V battery charging available, the COUT pin gate drive is fixed by the BAT pin voltage when charger is connected to PACK+ and PACK- (datasheet, section 9.4.6). So, is it sufficient to choose a NMOS with Vgs(th) more than the lowest allowed charging Vbat to inhibit or not the charge ?
Thanks.

0 Onyx Ahiakwo over 7 years ago in reply to user3985960

TI__Guru* 76230 points

Hi
You would not want to inhibit charging during 0V charging. You want to make sure the battery gets to a high enough voltage to turn the charge pumps on
thanks
Onyx

0 user3985960 over 7 years ago in reply to Onyx Ahiakwo

Prodigy 30 points

Hello,
Yes, I want to make sure to charge the battery when its voltage gets high enough.
So, could I only chose the right transistors for that ?
What is the difference between this method and the charge inhibition function ?
Thank you.
Arnaud

0 Onyx Ahiakwo over 7 years ago in reply to user3985960

TI__Guru* 76230 points

Hi Arnaud,
HTe charge inhibit function prevents charging when the 0V is due to a short, while the 0V charging is when the 0V is caused by self discharge. The voltage levels in these two different conditions would be different.
yes, you have to choose the right transistor.
thanks
Onyx

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BQ2970: 0V battery charge function, which is "available" and which "anavailable" part references ?