LMR23625-Q1: Minimum capacitance of Cvcc

tateo yamashiro

Part Number: LMR23625-Q1

Hi,

We got a question from the customer about LMR23625-Q1.
Could you help us?

[Question]
How much is the recommended minimum capacitance of Cvcc? They are considering using GRM155R61225KE11# for Cvcc. They are concerned DC bias effect and temperature characteristics.

Best Regards,
tateo

over 6 years ago

0 Timothy Hegarty over 6 years ago

TI__Guru 74052 points

Hi Tateo-san,

Thanks for your enquiry. I copied the product expert for clarification regarding minimum VCC capacitance.

Note that we generally recommend a ceramic decoupling cap with X7R dielectric for best temperature and voltage coefficient performance.

Regards,
Tim

0 tateo yamashiro over 6 years ago in reply to Timothy Hegarty

Guru 10890 points

Hi, Thank you for your reply. We look forward to your feedback.

Best Regards,
tateo

0 Katelyn Wiggenhorn over 6 years ago in reply to tateo yamashiro

TI__Genius 11040 points

Hello Tateo,

The minimum recommended VCC capacitor is 2.2uF. As Tim mentioned, we also recommend a ceramic capacitor with X7R dielectric.

Best Regards,
Katelyn

0 Arief Hernadi over 6 years ago in reply to tateo yamashiro

TI__Mastermind 23845 points

Hi,

I don't think we have data on the minimum capacitance of the CVCC.

We have always using a 2.2uF, 16V , X7R capacitor for our testing such as the one in the EVM

The part number is GRM188Z71C225KE43

Thanks

-Arief

0 tateo yamashiro over 6 years ago in reply to Arief Hernadi

Guru 10890 points

Hi, Thank you for your reply. They would like to use GRM155R61C225KE11# which is their standard parts. The DC bias effect and temperature characteristics are a little bit inferior to GRM188Z71C225KE43. Therefore they are expecting to able to use this parts for Cvcc. If this parts is used for Cvcc under the following condition, what kind of problem will the IC be occurred? And it would be helpful, if you provide the minimum recommended capacitance of Cvcc.

Vin=9.5 to 16V
Vout=5V or 7V
Iout=2A
fsw=440kHz *sync to external clock

Now LMR23625-Q1 is used in final prototype. The IC seems stable operation using GRM155R61C225KE11#. So if there is no concerns to use this capacitor, they would like to use this.

I know it's a big ask, and I appreciate you doing it for us.

Best Regards,
tateo

0 Arief Hernadi over 6 years ago in reply to tateo yamashiro

TI__Mastermind 23845 points

Hi Kohsuke,

Yes I think as long the characteristic is similar to the

https://psearch.en.murata.com/capacitor/product/GRM188Z71C225KE43%23.html

I think it should be ok to use other part with similar characteristic.

I see the customer have the 0402 capacitor as their standard parts.

One thing I check is the DC bias at 4V should be similar to the part number above (maybe use 2 to compensate the 0402 components over temperature?)

Thanks

-Arief

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LMR23625-Q1: Minimum capacitance of Cvcc