TPS56A37: Circuit Component Calculation

Ming Guo

Part Number: TPS56A37

Tool/software:

Hi,

We are in the process of replacing an existing buck regulator circuit with TI TPS56A37 4.5V to 28V Input, 10A, Synchronous Buck Converter.

However, I noticed the calculated values for Rent and Renb (resistor for setting UVLO) are very different (in fact they are negative) from the ones generated by TI WEBENCH® Designer. Please see attached spreadsheet for details.

TPS56A37RPAR Calculation Sheet.xlsx

Thanks!

4 months ago

0 Tahar Allag 4 months ago

TI__Mastermind 32350 points

Hello Ming,

the VSTOP and VSTART need to have more margin between them. they are too tight as they are now.

Thanks!

Tahar

0 Ming Guo 4 months ago in reply to Tahar Allag

Prodigy 120 points

Hi Tahar,

Thanks for the reply. I also noticed the calculated values for Rent and Renb are different from the ones generated by TI WEBENCH® Designer even when VSTOP and VSTART have large margin. Although their Rent/Renb ratios are similar). Is TI WEBENCH® Designer programmed to be minimizing the resistor values while keeping the same ratio?

Best regards,

Ming

0 Calan Elaya 4 months ago in reply to Ming Guo

TI__Genius 11155 points

Hi Ming,

I will respond this week to this.

Thank you,

Calan

+1 Calan Elaya 4 months ago in reply to Ming Guo

TI__Genius 11155 points

Hi Ming,

Webench model will have some differences between the model and datasheet. The model may display slightly different values but overall design is similar. Please use both the webench model and datasheet/ userguide as a guide for the design.

Hope this helps. If this helped resolve your issue, please don't forget to click "This resolved my issue"

Thanks,

Calan

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TPS56A37: Circuit Component Calculation