TPS65131: Chip application problem

Tonyx.wu

Part Number: TPS65131

Tool/software:

I would like to ask about the TPS65131 component. The measured FBP voltage is not within the range specified in the datasheet. One is around 1.36V and the other is 1.42V. The Vref voltage is 1.176V, which is also out of the range specified in the datasheet. This will cause the set output voltage to be incorrect. Could you please help me figure out the reason for this? If there is any problem with the schematic diagram, please check it for me. Thank you!

7 months ago

0 Colin Chen 7 months ago

TI__Mastermind 22071 points

Hi Tonyx,

Our spec in datasheet can be guaranteed. In you schematic, i saw the cff is too large which can coupling much ripple into FB. And this can cause the FB voltage is not accurate. You can remove it and test again.

Thanks,

Colin

0 Tonyx.wu 7 months ago in reply to Colin Chen

Genius 4225 points

I removed the Cff and retested it. There is still the same problem. Please help see where else there is a problem and give suggestions for modification. Thank you!

0 Colin Chen 7 months ago in reply to Tonyx.wu

TI__Mastermind 22071 points

Hi Tonyx,

ok, could you test the waveforms of below marking points.

Other thing is how you test the FB voltage, It was done by a voltage meter? Where did you select GND?

The schematic looks good to me, could you share the layout to me for cheching?

Thanks,

Colin

0 Tonyx.wu 7 months ago in reply to Colin Chen

Genius 4225 points

Is there an Excel spreadsheet that automatically calculates for this chip, mainly for all the peripheral parameter values? If there is, please provide it.

0 Colin Chen 7 months ago in reply to Tonyx.wu

TI__Mastermind 22071 points

Hi Tony,

Sorry, we don't have such Excel spreadsheet.

Thanks,

Colin

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TPS65131: Chip application problem