TPS54331-Q1: Review and root cause for malfunctioning

NIRMAL ARAVIND A R

Part Number: TPS54331-Q1

Hi,

We have used TPS54331QDRQ1 in our design as regulator.

Attached the schematic for your review.

We have simulated using Webench and results as good and Output is 3.3V. But practically, we are getting only 1.6V as output.

We tried to change Feedback resistors also(R35,R38), still we get only 1.6V as output for any values of resistor.

Please let us know what could the possible reasons.

Thanks in advance!

Regards

Nirmal Aravind

0 Zhao Ma over 4 years ago

Hi, Nirmal -san

The schematic looks okay.

1. Could you probe some waveforms? including Vout and PH pin voltage.

2. Could you send me the layout file for review?

3. If you increase Vin from 4V to 6V, and check Vout again.

0 NIRMAL ARAVIND A R over 4 years ago in reply to Zhao Ma

Hi Zhao Ma,

Increased the input to 5V and now it works fine.

Thank you for the support.

But it is supposed to work at 4V. Right?

Or what can be the possible reason for not working at 4V?

Regards

Nirmal

0 Young Zhao over 4 years ago in reply to NIRMAL ARAVIND A R

Hi,

Zhao will help on this later.

BRs,

Young

0 Zhao Ma over 4 years ago in reply to NIRMAL ARAVIND A R

Hi, Nirmal

Confirm with you:

When Vin=4V, if add 0.5A loading, is Vout normal?

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