BQ24090: the CHG LED is always off when charging

john xiao

Part Number: BQ24090

Dear all:

I use BQ24090 charge the lithium battery,the sch is BQ24090 SCH.zip

when the battery is charge to 3.9V,pull out and insert the adapter multiple times,I found BQ24090 CHG LED is always off and the input current jumps between 150ma to 170ma.view BQ24090 Datasheet,no found the description of this state,please tell me what causes this?thanks a lot.

over 5 years ago

0 Bill Johns over 5 years ago

TI__Guru 65736 points

Hello

I reviewed the schematic and everything looks OK.

When you see 150mA to 170mA what is the battery voltage at OUT pin?

0 john xiao over 5 years ago in reply to Bill Johns

Intellectual 470 points

Hello Bill:

The BQ24090 out pin connected to B+ via a 0.3 ohm wire,if the Impedance is too large,will it cause this problem?

0 Bill Johns over 5 years ago in reply to john xiao

TI__Guru 65736 points

Hello
Resistance between the OUT pin and battery can cause problem. Battery voltage is sensed at the OUT pin and resistance will cause an error in this voltage during charging.

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BQ24090: the CHG LED is always off when charging