TPS65310A-Q1: compensation equation

Clement Magnien

Prodigy 90 points

Part Number: TPS65310A-Q1

Hello,

Could you check the compensation network equation. It doesn't seem to give the good value for C2,C1,R3

Regards,

over 4 years ago

0 Krishnamurthy Hegde over 4 years ago

TI__Expert 8730 points

Hello,

There is no issues with BUCK1 compensation calculation equations. What issue are you facing with these equations? You need to consider de rating values for output capacitors. Below is one application note related to this topic.

www.ti.com/.../slva909.pdf

Regards,

Murthy

0 Clement Magnien over 4 years ago in reply to Krishnamurthy Hegde

Prodigy 90 points

Hello,

if you calculate R3 with 25% derating for the capacitor and the formula (5)

R3 =13.1k not 8.25k?

Regards,

0 Krishnamurthy Hegde over 4 years ago in reply to Clement Magnien

TI__Expert 8730 points

Hello, It is possible that in the datasheet they considered ~ 50% derating for the capacitor. In the application note, I just took 25% derating for a typical case. These equations are just a starting point and you need to do the actual measurements and based on the measurements, you may need to fine tune these values.

Regards,

Murthy

0 Clement Magnien over 4 years ago in reply to Krishnamurthy Hegde

Prodigy 90 points

Hello,

No even with 50% it doesn't make sense. Could you ask the application team who worked on this datasheet to check the calculation to provide to your customer a clear explanation of how to set the control loop?

Regards,

0 Krishnamurthy Hegde over 4 years ago in reply to Clement Magnien

TI__Expert 8730 points

Hello,

I am the applications engineer for this device and I reconfirm that equations are correct. Depending on the capacitors you use, in the worst case you can have ceramics capacitor de rating up to 50%. Please refer to the application note and i have provided compensation component values for different options and measurement results are also provided.

Regards,

Murthy

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TPS65310A-Q1: compensation equation