BQ24251 question

syed hamad

Other Parts Discussed in Thread: BQ24251

Dears,

Need your help on an issue with TI battery charger chip BQ24251

With 5V input power from USB connected, and with battery disconnected, the system output voltage from this IC shows a square wave riding on the DC. With battery connected the output voltage is ok. In datasheet we find that no battery condition is valid.

regards,

syed hamad.

over 11 years ago

0 Jeff F over 11 years ago

TI__Guru**** 169756 points

The square wave is the battery detection circuit. It is expected and shown in datasheet figure 5.

0 syed hamad over 11 years ago in reply to Jeff F

Expert 1120 points

Thanks for your responce jeff..

But, why it is stated that no battery condition is valid in Datasheet.

is it something related to BC1.2 specification?since, bq24251 incorporates NEW! Dead Battery Provision,

Supports DBP clause of BC1.2 to sync up system to Dead Battery.what does this actually mean.

regards,

syed

0 syed hamad over 11 years ago in reply to syed hamad

Expert 1120 points

Hi,

We still have the situation.

But I understand it is due to the AnyBoot battery detection algorithm – page 27 of datasheet, which sets in when no battery is detected. Is there any way of disabling this?

regards,

syed hamad

0 Jeff F over 11 years ago in reply to syed hamad

TI__Guru**** 169756 points

You can disable battery detection by either:

1. disabling battery charge termination

2. enabling PTM mode (which also disables input current limit feature)

Power management

Power management forum

BQ24251 question