TPS56A37: PG circuit with LED

Roy Chou1

Part Number: TPS56A37

Tool/software:

HI Team,

Would below circuit work? when the device abnormal, the PG pin would short to GND and the LED would be brought up. (LED VF is around 3V) (I see PG can sink 10mA in datasheet)

Regards,

Roy

20 days ago

0 Calan Elaya 20 days ago

TI__Expert 5865 points

Hi Roy,

Can you more clearly indicate what the drawing shows? 5V at the top, what ohm value is the resistor in the middle?

Usually this pin goes low if the Vout falls out of threshold. So you would like to have an LED go high once PG goes low is that correct?

Thanks,
Calan

0 Roy Chou1 20 days ago in reply to Calan Elaya

TI__Genius 13965 points

Hi Calan,

1. It's 620ohm

2. Yes, LED go high when PG goes low.

Roy

0 Hedy H 20 days ago in reply to Calan Elaya

Prodigy 50 points

Hi Calan,

Is the resistor more suitable with 200 ohms according to the 10mA PG sink current?

Best regards,

Hedy

0 Calan Elaya 19 days ago in reply to Hedy H

TI__Expert 5865 points

Hi Roy, Hedy,

The minimum resistor value to use here should be 500ohms. This is derived from the 10mA PG minimum sink current, and the 5V you are looking to pull up to. So the 620ohm or greater would work for this. So the design here should work, I don't see an issue.

Attached here is a helpful Application report that is also good to refer to: https://www.ti.com/lit/an/slva485/slva485.pdf

Here is also the description of PGOOD from the TPS56A37 datasheet:

Hope this helps!

If this helped answer your question, please don't forget to click "This resolved my issue"

Best,
Calan

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TPS56A37: PG circuit with LED