BQ25172: Problem with Vout_ovp

Charlie Zhang

Part Number: BQ25172
Other Parts Discussed in Thread: BQ2002

The typical Vout-ovp is 1.7V, but how does a 1.2V NiMH battery achieve 1.7V to terminate the charge cycle? The max voltage of battery is around 1.55V, and it still charges the full charged batteries more than 3 hours.

over 1 year ago

0 Charlie Zhang over 1 year ago

Prodigy 30 points

The last picture is specificatoin of GP NiMH battery.

0 Bill Johns over 1 year ago in reply to Charlie Zhang

TI__Guru 65626 points

Hello

The BQ25172 is a timer-based charger, resistor on the TMR pin will set charge duration between 4 and 22 hours. Charge current should be set below 50% of batter capacity.

1.7V is an overvoltage fault condition, not used for normal charge cycle.

A Fast Charger such as BQ2002 will apply higher current and monitor voltage or temp to terminate charge.

0 Charlie Zhang over 1 year ago in reply to Bill Johns

Prodigy 30 points

Thank you for your relpy.

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BQ25172: Problem with Vout_ovp