BQ24090 CHG Doesn't go low

/CHG pin only goes low after the first charge cycle. It remains high impedance for recharge cycles. You have to remove and replace the battery OR remove and replace the input power OR take TS to GND and back up to reset the /CHG logic.

What you've suggested, I already know & had tried before but they don't work.

Anyway, I've found out that the part placement are crucial & tested it & it solved my problem.

Hi

I have a similar problem with the BQ24090. After applying USB power the charge current toogles on and off with app 25mS interval.

What did You do with the PCB layout etc to make Your design work?

Thanks in advance

Do you have a system load that is pulling more than the termination current every 25mS? 

No, my system load is 1.6mA DC.

I was thinking that the 25mS interval has something to do with the battery detech routine. The BQ24090 is checking for missing battery when the USB voltage is connected and a new charge cycle is initiated.

The fault is not present every time I connect the USB, it might have something to do with the battery voltage (more or less charged).

Hi

I found the failure. I wasn't the BQ24090 nor the battery but the connector between the battery and charger circuit. The resistance was changing from 10m to 200m Ohm causing the charger IC to say "Bad Battery".

The part placement was that the cap on the prototype board was way too far. Follow the EVM if you have one, else, use a picture as the image in EVM Guide (slu392a.pdf) wasn't clear enough for me.

Another problem I encountered was when the hand-soldered microUSB connector was not properly done, similar problem would occurs.