WEBENCH® Tools/LMR23625: Does the capacitor being used consider DC bias？

Shinichi Inoue

Guru 21991 points

Part Number: LMR23625

Tool/software: WEBENCH® Design Tools

Dear Specialists,

My customer is considering LMR23625 and using a WEBENCH.

He has a question of using capacitor.

I would be grateful if you could advise.

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I was confirmed the operation of LMR23625 with WEBENCH.

In the result, does the value of the external capacitor consider the DC bias characteristic?

For example, in the simulation result of 【LMR23625】, the output capacitor part number is 【GRM32ER61E226KE (25 V withstand voltage 22 μF)】.

According to the datasheet , capacity at 12 V is about 7 to 8 μ.

Since two capacitors are used, it becomes 14 to 16 μF.

Should it be added more in parallel to be 22 μF?

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I appreciate your great help in advance.

Best regards,

Shinichi

LMR23625_IN22-28V_OUT12V_2.2A_20180130.pdf

over 7 years ago

0 Katelyn Wiggenhorn over 7 years ago

TI__Genius 11040 points

Hi Shinichi,

Webench will take into account derating of the capacitors. For this design Webench is recommending 2 x 22uF @ 25V, X5R. If the customer has specific transient requirements for undershoot and overshoot, they can verify with the equations from page 21 of the datasheet:

Please let me know if you have any additional questions.

Best Regards,

Katelyn Wiggenhorn

0 Shinichi Inoue over 7 years ago in reply to Katelyn Wiggenhorn

Guru 21991 points

Hi Katelyn,

Thank you for your reply.

I understand WEBENCH is considered DC bias of the capacitor and chosen 2 x 22uF.
In addition considered rated voltage and type.

I'll share this information with the customer.
If he has an additional question, I consult you again.

I appreciate your great help.

Best regards,
Shinichi

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WEBENCH® Tools/LMR23625: Does the capacitor being used consider DC bias？