TPS61088-Q1: Calculation of loop stability

user6265022

Part Number: TPS61088-Q1

Hello team,

The COMP pin is the output of the internal error amplifier.
An external compensation network comprised of resister R5, ceramic capacitors C5 and C8 is connected to the COMP pin.

Please advise on the formula to calculate the optimal R5, C5, C8.

Have Excel formulas?

Best regards

over 4 years ago

0 Helen chen over 4 years ago

TI__Mastermind 40080 points

Dear Sir,

Please check the answer in this FAQ:

0 Helen chen over 4 years ago

TI__Mastermind 40080 points

Dear Sir,

I found you reject the original answer.

Actually you can also found the formula of R5, C5 and C8 on datasheet page 17 and 18. It is very clear.

Do you have any other request?

0 user6265022 over 4 years ago in reply to Helen chen

Prodigy 125 points

Hi Helen,

Thank you for the answer.

Some parameters cannot be resolved yet.

Q1) How to choose the loop crossover frequency, ƒC?

Q2) How to calculate GEA?

Best Regards,

0 Helen chen over 4 years ago in reply to user6265022

TI__Mastermind 40080 points

Dear Sir,

For the boost converter, fc is customer defined, if there's no big load change in the system, therefore the load dynamic performance is not an issue, generally we set fc=5k Hz. But if there's some load dynamic requirement, generally, we set fc=10k-15k. higher fc is not recommended because of the right half plane zero limit.

You can check the GEA from the EC table. It is 190uA/V.

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TPS61088-Q1: Calculation of loop stability