LM63635QDRREVM: RE: Design switching frequency.

Hrishikesh Kamble

Part Number: LM63635QDRREVM

Hello,

We design the buck converter using the "LM63635DQPWPRQ1". Its reference design have the default switching frequency is 2.1MHZ.

But its datasheet says we can operate that on the 400kHZ also, we just wanted to know that by using 2.1Mhz switching frequency for this switcher is their any issue with its performance?

Regards,

Hrishikesh.

over 1 year ago

0 Colin Chen over 1 year ago

TI__Genius 16761 points

Hi Hrishikesh，

There is no problem to change switching frequency from 2.1MHZ to 400kHz. But is need to recalculate inductance and output capacitance. I suggest you increase the inductance 2.2uF to 12uF and use 22uFx3 as output capacitance.

Thanks

Colin

0 Hrishikesh Kamble over 1 year ago in reply to Colin Chen

Prodigy 250 points

Dear Colin,

Thanks for your response.

But due higher switching frequency (like 2.1Mhz) is there any performance issue with the switcher?

Like inductor core loss or ripple at output?

Regards,
Hrishikesh.

0 Colin Chen over 1 year ago in reply to Hrishikesh Kamble

TI__Genius 16761 points

Hi Hrishikesh，

Higher switching frequency will cause ripple at output smaller. But inductor core loss and switch loss will be higher.

Thanks

Colin

0 Hrishikesh Kamble over 1 year ago in reply to Colin Chen

Prodigy 250 points

Dear Colin,

So should we move to 400kHZ? Please suggest us?

Reagrds,

Hrishikesh.

0 Colin Chen over 1 year ago in reply to Hrishikesh Kamble

TI__Genius 16761 points

Hi Hrishikesh,

In your design, I suggest you better not move to 400kHz. Because your inductance is not enough.

Thanks

Colin

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LM63635QDRREVM: RE: Design switching frequency.