BQ25713: Input Current too high

Dominik Dungl

Part Number: BQ25713

Hi,

I am trying to limit the input current of BQ25713 to currents depending on what kind of USB PD charger is plugged in. Otherwise, the charger sometimes sinks more current than is officially supported (e.g. 3A/5V instead of 1A/5V)

I send the limit to the IIN_HOST register according to the data sheet, but it seems to be ignored. For example, I set the input current to 800mA, but reading out IIN_DPM yields 1400mA and IIN (from IIN_CMP_IN) 1300mA.

I suspect the Input Current Optimizer (ICO) overwrites my setting, after it tested the source is actually good for more current?

But during initialization, EN_ICO_MODE is set to zero, so it should be turned off.

Is this the correct way to limit power?
Can I check if the IIN_HOST setting was received correctly?

Kind regards,
Dominik

over 3 years ago

+1 Tiger Zhou over 3 years ago

TI__Mastermind 33305 points

Hi, Dominik,

If the adapter current capability is known, we can use the IIN_HOST to set the current limit directly; otherwise, we can enable ICO for unknown adapters.

There is an IIN_DPM register, which reflects the current limit in use, can check if IIN_HOST setting is correct.

Regards,

Tiger

0 Dominik Dungl over 3 years ago in reply to Tiger Zhou

Prodigy 40 points

Hi,

Thank you for your reply.

I did this, but discovered that when I re-plug the USB connection the IIN setting gets lost and a higher value gets set. I don't know if that is a bug on my side or normal behaviour, but I now resend the settings with the charge current required for the watchdog.

Thanks!
Dominik

0 Khalid Bairuti over 3 years ago in reply to Dominik Dungl

TI__Expert 4780 points

Hi Dominik,

After CHRG_OK goes HIGH, the charger sets default input current limit in REG0x0F/0E() to 3.25 A.

Upon adapter removal, CHRG_OK will go LO. When re-attached, CHRG_OK goes HIGH again and the default input current limit is set again.

Thanks,

Khalid

0 Dominik Dungl over 3 years ago in reply to Khalid Bairuti

Prodigy 40 points

Hi,

I did not think about CHRG_OK going low, thank you, that explains everything.

Kind regards,
Dominik

Power management

Power management forum

BQ25713: Input Current too high