BQ24392 CHG_DET

Chris Hamilton

Hi, I am curious why the datasheet recommends placing a diode on CHG_DET? I am looking to utilize the charge detection to signal to a microprocessor if high current is available on the 5V line. Our design then plans to utilize the power not to charge, but to drive higher current components. If, the negotiation fails the microprocessor will drop back to a firmware update/USB communication state. I have looked on the forums, but the only discussion drives a charger EN line directly with CHG_DET.

over 10 years ago

0 Adam Torma over 10 years ago

TI__Mastermind 45575 points

The datasheet states that placing a diode on CHG_DET is optional on page 11.

"CHG_DET is a push-pull output pin. An external pull-up and Diode are shown to depict a typical 3.3V system. The pull-up resistor and diode are optional. The pull-up range on the CHG_DET pin is from 3.5V to VBUS. When VBUS > 7V, CHG_DET will be clamped to 7V."

Using CHG_DET to signal the microprocessor that high current is available is a valid application for this device.

Adam