TPS51216: TPS51216 PGOOD sag issue

Yang Wu

Part Number: TPS51216

Hi Team,

My customer is using TPS51216 and have a sag issue on PGOOD (either with 200k, 100k, or 10k pull-up resistor) when VDDQ & VTT are normal, do you have some ideas here that how it can happen?

Thanks a lot.

Best regards,

Yang

over 4 years ago

0 Weidong Zhu over 4 years ago

TI__Expert 5965 points

Hi Yang,

Can you ask customer to remove all other connections on PGOOD, and just keep the connection to TPS51216 and pull up voltage to see if this issue still exist?

Regards,

Weidong

0 Yang Wu over 4 years ago in reply to Weidong Zhu

TI__Expert 3320 points

Hi Weidong,

The issue still exists. The sag is around 1ms shown as below:

0 Yang Wu over 4 years ago in reply to Yang Wu

TI__Expert 3320 points

Hi Weidong,

Do you have some updates?

thanks a lot.

0 Weidong Zhu over 4 years ago in reply to Yang Wu

TI__Expert 5965 points

Hi Yang,

We are still reviewing this. Will get back to you soon.

Regards,

Weidong

0 Weidong Zhu over 4 years ago in reply to Weidong Zhu

TI__Expert 5965 points

Hi Yang,

From the schematic we can not see anything that can cause PGOOD sag. Can you help to provide more information below?

1. What's the failure rate? Is customer seeing this issue on every board?

2. In the waveform above, did customer disconnect all other connections on PGOOD other than pull up and the connection to TPS51216?

3. Can you ask customer to provide Zoomed in VTTSNS, VDDQSNS and VTTREF waveform during PGOOD sag? It will be more helpful to have proper vertical scale so we can see if there is glitch on these waveforms.

4. After the above debug, we can ask customer do A-B-A swap to see if the issue still exist.

Regards,

Weidong

0 Yang Wu over 4 years ago in reply to Weidong Zhu

TI__Expert 3320 points

Hi Weidong,

I have sent you an email to discuss this issue and closed this threat.

thanks a lot.

Yang

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TPS51216: TPS51216 PGOOD sag issue