TPS548B28: Improper PG signal

Nini Zhong

Part Number: TPS548B28

Hi team, here is a technical question might want your help.

When input VIN is12V, EN= 0V, e PG signal 0.89V? (PG pull-up to 3.3V, pull-up resistor 10K). Is this phenomenon proper? Or if there is any possibility that something is wrongly set?

over 2 years ago

+1 David_Daniels over 2 years ago

TI__Mastermind 23600 points

The status of the PGOOD pin is dependent on the voltage of VCC pin.

If the PGOOD pullup resistor connects to an external supply that is NOT connected to the VCC pin, the PGOOD will be High when en=0V.

The EC table and description text states the VCC voltage needs be greater than 1.5V for a valid PGOOD signal.

The oscilloscope waveform in the datasheet shows the PGOOD signal when using VCC pin as the pullup voltage source

0 Nini Zhong over 2 years ago in reply to David_Daniels

TI__Genius 13105 points

Thanks!

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TPS548B28: Improper PG signal