TPS54331: TPS54331 Schematic check

user6158327

Part Number: TPS54331

Dear friends,

Please help check the schematic of TPS54331. Vin=5V, Vout1=3V3, Vout2=1V2. For now, no 3V3 and 1V2 in the output. Thanks.

This is used to power the F28377D DSP.

over 5 years ago

0 Shawn Nie over 5 years ago

TI__Genius 10070 points

Hi,

L8 and L9 are too large, It would be better to select 2.2uH.

And R17 and R23 are also too large, you can use Webench to optimize the compensation values.

https://webench.ti.com/power-designer/switching-regulator/customize/157?AppType=None&Flavor=NA&O1I=3&O1V=3.3&Topology=BUCK&VinMax=5&VinMin=5&VoltageOption=NA&base_pn=TPS54331&flavor=NA&lang_chosen=en_US&op_TA=25&optfactor=3&origin=pf_panel&refpage=https:%2F%2Fwww.ti.com%2Fproduct%2FTPS54331

Shawn

0 user6158327 over 5 years ago in reply to Shawn Nie

Intellectual 280 points

Hi Shawn，

I have tried to use Webench to optimize the compensation values. The result is the below picture. And I use TINA to simulation the result. But the output voltages is less than 3.3V, and the powering up for too long.

Can you help me to fix it?

Best Regards,

Boyuan

0 Shawn Nie over 5 years ago in reply to user6158327

TI__Genius 10070 points

Hi,

You set soft start capacitor 27nF, that is why the soft start time is long.

And for the output voltage, I think it is measurement error, you can zoom in the waveform and double check it.

Shawn

0 user6158327 over 5 years ago in reply to Shawn Nie

Intellectual 280 points

Hi，

I have tried to adjust the value of the soft-start capacitor, the soft-start time is shorter.

But the output voltage did not make changes.

I don't quite understand where the problem is.

Boyuan

0 Shawn Nie over 5 years ago in reply to user6158327

TI__Genius 10070 points

Hi,

Please zoom in simulation waveform, and let's check it.

Shawn

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TPS54331: TPS54331 Schematic check