Calculating L1 for TPS50601 using example.

Hi John,

Actually, I get 5.46uH, not the 2.78uH the datasheet is showing. I was considering the 2x factor, but that would be 5.56uH, so it is not exactly 2x. I thought I was doing my math correctly.

Here is my excel data and the formula that gives me 5.46:

Vinmax 6.3 (B6)
Vout 3.3 (B7)
Kind 0.1 (B8)
Io 6 (B9)
fsw 480000 (B10)


=((B6-B7)/(B9*B8))*(B7/(B6*B10))

What am I doing wrong?

Thanks,

Todd

I don't think you are doing anything wrong. My calculation agrees with yours. I did not write that datasheet, so I cannot say where the error might be. I don't think it is a coincidence that the value is off by a factor of 2.

OK, that's good. Didn't want an embarrassing math error! :-)

An obvious 2x error would be if Kind was supposed to be 0.2 instead of 0.1. That would give me 2.73uH.

Thanks,

Todd

Hi John,

Any updates here?

Thanks,

Todd