BQ24085: Vin presence detection with /PG Signal

Vicente Simo

Prodigy 30 points

Part Number: BQ24085

Hello, I want to use /PG signal as a Vin presence detección signal, but we I remove Vin /PG signal doesn't change.

Could you tell me if I can use /PG signal for this purpose or it only Works as an overvoltage detection?

Thanks

over 4 years ago

0 Anthony P Pham over 4 years ago

TI__Mastermind 23280 points

Hi Vicente,

Welcome to E2E!

The /PG signal can be used for the following:

Based on what you've said, it looks like you are seeing the DETECTED, OVERVOLTAGE state and transitioning to NOT DETECTED.

0 Vicente Simo over 4 years ago in reply to Anthony P Pham

Prodigy 30 points

OK, The problem is that when I have a battery connected, and I remove Vin, /PG doesn't change to high impedance.

0 Anthony P Pham over 4 years ago in reply to Vicente Simo

TI__Mastermind 23280 points

HI Vicente,

Can you provide a schematic? Can you also provide the voltage and current you have at the input?

0 Vicente Simo over 4 years ago in reply to Anthony P Pham

Prodigy 30 points

Yes, below you can see it.

There is a 5v USB input (Vdc), a resistive divider for battery level measurement, and a switch circuit that changes Vout from Vdc to Vbat when Vdc is removed.

With this SCH /PG doesn't work neither with overvoltage neither with removing Vin

Thanks

0 Anthony P Pham over 4 years ago in reply to Vicente Simo

TI__Mastermind 23280 points

Hi Vicente,

Can you provide a scope shot of the input voltage and current with /PG when this happens? Can you also provide a scope shot for the output voltage and waveform with /PG when this happens?

0 Anthony P Pham over 4 years ago in reply to Anthony P Pham

TI__Mastermind 23280 points

Hi Vicente,

With the /PG pin, assuming you are using a microcontroller, please connect a pull-up resistor between the processor's power rail and the PG terminal.

Power management

Power management forum

BQ24085: Vin presence detection with /PG Signal