LM46002: Powering three different simple switcher model numbers from the same source, do I really need nine input-side bulk caps?

Steve Kleiser

Part Number: LM46002

Greetings,

For a single board with 3.3V, 5V, & 15V supplies, I downloaded recommended Webench designs. Each of the three switchers is a different part number, & each includes three input-side bulk capacitors of various values. So my power supply would have nine of them.

Do I really need all those caps?

Since they're all in parallel, are the recommended values affected?

Thanks,

over 5 years ago

0 Katelyn Wiggenhorn over 5 years ago

TI__Genius 11040 points

Hello,

No, you will not need to have nine bulk ceramic capacitors. You will need at least one for each converter.

For example, you could use 1x10uF ceramic at the input of each converter with 1x high frequency bypass capacitor at the input of each converter.

Please let me know if anything is still unclear or if you have any additional questions.

Best Regards,
Katelyn

0 Katelyn Wiggenhorn over 5 years ago in reply to Katelyn Wiggenhorn

TI__Genius 11040 points

Hello,

I want to follow up on your question. Do you have any additional questions or is anything unclear?

Best Regards,
Katelyn

0 Katelyn Wiggenhorn over 5 years ago in reply to Katelyn Wiggenhorn

TI__Genius 11040 points

Hello,

Due to inactivity I am going to close this thread, but please let me know if you have any additional questions.

Best Regards,
Katelyn

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LM46002: Powering three different simple switcher model numbers from the same source, do I really need nine input-side bulk caps?