BQ24800: charging current reduce due to PWM or input current reduce?

Fred Cheng

Expert 5730 points

Part Number: BQ24800

Hi team,

we want to know when charging current reduce due to heavy load under current limit triggered,

does PWM do anything to reduce charging current or its behavior is still the same?

over 1 year ago

0 Christian Moyer over 1 year ago

TI__Mastermind 32481 points

Hello Fred,

Fred Cheng said:
we want to know when charging current reduce due to heavy load under current limit triggered,

The timing can vary depending on Input Voltage/Current limit, Battery Voltage/Charge current and system load.

Fred Cheng said:
does PWM do anything to reduce charging current or its behavior is still the same?

Yes, The PWM will change if the Charge current is reduced.

Best Regards,

Christian.

0 Fred Cheng over 1 year ago in reply to Christian Moyer

TI__Expert 5730 points

Hi Moyer,

but if it only reduce the charging current out of the buck and battery voltage is still the same, so the duty cycle should be the same, right?

so just curious what exactly does the PWM changed?

+1 Christian Moyer over 1 year ago in reply to Fred Cheng

TI__Mastermind 32481 points

Hello Fred,

Fred Cheng said:
but if it only reduce the charging current out of the buck and battery voltage is still the same, so the duty cycle should be the same, right?

so just curious what exactly does the PWM changed?

I'm sorry for the confusion. Yes, the PWM should remain the same if charge is reduced, but If the charge current is reduce to a low value the PWM mode could switch to PFM mode.

Best Regards,

Christian.

Power management

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BQ24800: charging current reduce due to PWM or input current reduce?