BQ25886: source detection

Aida Madelkhanova

Part Number: BQ25886
Other Parts Discussed in Thread: BQ25890

Hi team,

If D+ and D- are used to connect the MCU to a PC probably it will not be possible the charger to detect the USB source, i.e. will the charger influence the USB communication?

Thanks and regards,

Aida

over 2 years ago

+1 Michael Emanuel35 over 2 years ago

TI__Mastermind 40325 points

Hi Aida,

The host must be able to HIZ D+/D- pins during charger input detection process so they can be driven by charger. If the host is unable to HIZ D+/D- pins, a USB switch is needed to isolate the D+/D- pins of the host and the charger. Please see PWR664 EVM for example with BQ25890.

Regards,

Mike Emanuel

0 Aida Madelkhanova over 2 years ago in reply to Michael Emanuel35

TI__Intellectual 2380 points

Hi Mike Emanuel,

Thanks for your help, this is clear.

I have other question on ILIM. According to following: IINDPM loop regulates ILIM pin voltage at 0.8V. When ILIM pin is less than 0.8V, the input current can be calculated by IIN = KILIM x VILIM / (RILIM x 0.8V). This is how the current should be calculated, there is also formula for max current limit.

How is VILIM determined if it is less than 0.8V?

Thank you.

Kind regards,

Aida

0 Michael Emanuel35 over 2 years ago in reply to Aida Madelkhanova

TI__Mastermind 40325 points

Hi Aida,

VILIM is the actual voltage on the ILIM pin.

Regards,

Mike Emanuel

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BQ25886: source detection