BQ24090: Battery not charging

Hello Robert

I could not find the attached diagram, could you please upload, thanks.

Thanks Kerry, I have now uploaded the picture!

Hello Robert

I find that the PG and CHG pins are not connected, recommend that you could test the PG to check if the IC is power good, and test CHG waveform to check if IC starts charging.
Meanwhile, for preventing the possible impact of TS/NTC, you could connect this pin to VSS through an external 10k ohm resistor.
Hope this could help

Regards.

Hi Kerry,

I have done as you suggest. Unfortunately adding the 10K ohm resistor hasn't helped. The PG pin is low as expected however I have found that the CHG pin is at about 1.8V. Can you think why this might be?

Thanks,

Robert

Hello

As for the CHG pin voltage, the internal FET is open drain, so we should through a pull-up resistor to connect OUT pin.

Could you test the voltage of BAT pin.

Regards

Hi Kerry,

The voltage I am getting at the BAT pin is equal to the battery voltage (3.97V in this case) when the battery is attached and 0 when the battery is disconnected (but with Vin still applied)

Thanks,

Robert

Hello Robert

It seems that the SCH has no problem, so you could test all pins to confirm if all pins' voltage are normal. PG and CHG, you could refer the datasheet to connect it to OUT, for dedicate the state. By the way, how many boards do you make, is there any circuit board behave normal? Thanks

Regards