LMS3655: Question for inductance size

Lee, Sam

Part Number: LMS3655

Hi team,

For 24VIN, 12VOUT and 5A, Webench simulation of LM3655 currently recommends a large inductance(150uH), while 24VIN, 5VOUT and 5A is simulated with 10uH. Is it correct? Can you recommend the appropriate inductance value for 12VOUT/5A?

- Webench simulation Result for 24VIN, 12Vout and 5A

Thanks,

Best Regards,

Sam Lee

over 8 years ago

0 JohnTucker over 8 years ago

TI__Guru**** 191445 points

It appears there is a bug in Webench. At output voltages up to 5.99 V, the calculation works correctly and returns a value of 10 uH. at 6V output and above, the inductor value increases to > 100 uH and the the result includes fractional values such as 145.833 uH for the 10V output case. Just FYI using the standard inductor equation, I get 10 uH for 12V output as well. I'm going to move this to the Webench forum. They can see what is wrong and fix it.

0 Atul_Kulkarni over 8 years ago in reply to JohnTucker

Genius 4910 points

Hi Lee and John,

We are looking into the issue. We will get back to you on this.

Thanks and Regards,
Atul

0 Lee, Sam over 8 years ago in reply to Atul_Kulkarni

TI__Expert 6215 points

Thanks John and Atul.

Best Regards,
Sam Lee

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LMS3655: Question for inductance size