BQ24030: Change charging current depending on input source

Damon Kelly10

Part Number: BQ24030
Other Parts Discussed in Thread: BQ25155, BQ25120A, BQ25100

For the bq24030, is it possible to change the charging current depending on the input source?

My device uses about 60mA when running, but the "AC power source" can only supply about 100mA.

I would like a charge current limit of about 30mA when running off AC power input (for trickle charge), but up to 500mA when running off USB power input.

I was thinking of using a MOSFET switched by nUSBPG to add an extra resistor in parallel to the ISET resistor, to increase the charge current limit.

Alternatively, is there a way to prevent bulk/fast charge when running of AC power input?

over 4 years ago

0 Raheem over 4 years ago

TI__Mastermind 21590 points

Hello,

You can have a resistor in parallel to another resistor with a FET in series connected to the input source you want to control the current change.

You can use the CE pin

0 Damon Kelly10 over 4 years ago in reply to Raheem

Prodigy 200 points

Thanks Rahem.

Does the bq24030 work with a charge current set to 15mA?

0 Raheem over 4 years ago in reply to Damon Kelly10

TI__Mastermind 21590 points

Hello,

The minimum charge current for he BQ24030 is 100mA. For lower charge current, look at the BQ25120A, BQ25155 and BQ25100

0 Damon Kelly10 over 4 years ago in reply to Raheem

Prodigy 200 points

Hi Raheem,

Thanks for the details.

I set the charge current to 15mA, and it seems to work well enough.

It's well out of spec, so I suspect it won't be very accurate, but it doesn't really matter:

the charge terminates reliably for a full battery
there is a 6-hour timeout if that fails.

Power management

Power management forum

BQ24030: Change charging current depending on input source