LM5069: PGOOD Pin not working

Saurav Kulkarni

Part Number: LM5069

I'm using LM5069MM-1 for Power Supply and Inrush Control in the system.

Operating Voltage : 48V to 56V, Max. Current : 30A

PGOOD pin of the controller is pulled up to the output voltage with 100K resistor. I'm using this pin as a feedback to the microcontroller

Currently, microcontroller is not getting any feedback from PGOOD pin. Resistance between PGOOD pin and GND is 5 Ohm. although the UVLO and OVLO is functioning properly.

What could be the reason for this? Is this a know issue?

over 2 years ago

0 Rakesh over 2 years ago

TI__Guru** 106281 points

Welcome to E2E Saurav.

Is Vout coming up ? What is the load ?

Best regards

Rakesh

0 Saurav Kulkarni over 2 years ago in reply to Rakesh

Prodigy 45 points

Yes. Vout is working. Motor Driver is connected at the Load

0 Rakesh over 2 years ago in reply to Saurav Kulkarni

TI__Guru** 106281 points

Ok. Please share schematic and test waveform of Vin, Vout, PGOOD and output current

Best regards

Rakesh

0 Saurav Kulkarni over 2 years ago in reply to Rakesh

Prodigy 45 points

ti_Query_Schematic.pdf

Hi ! Sharing schematic here. Will share waveform images soon.
(Note : Capacitor C1 is not populated on the PCB)

Please find circuit to read PGOOD pin (Motor-Supply-FB) on micro-controller side below

0 Rakesh over 2 years ago in reply to Saurav Kulkarni

TI__Guru** 106281 points

10k between GATE to source of FETs acts as load for the LM5069. Can you remove those and then test.

Best Regards,

Rakesh

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LM5069: PGOOD Pin not working