LM5149: Inquiry about Bode Plot

Hello Jamie,

The calculator Bode results are calculated.  you want to compare phase at the cross over frequency.  the calculator is taking the difference from -180degree to the phase at the cross over to provide you with the phase margin.  It reports the phase margin, and this is all you need to consider.   compare this to the phase margin on the Bode plot of your bench measurement.  If you share the whole image of each would have been easier for the both of us to discuss.  Also, the phases maybe a lot different at high frequencies, you should only be looking at comparing the phase relationships up to and a little beyond cross over.  There are higher frequency poles and zeros potentially coming into play that are not be modeled in the spreadsheet.

I hope this makes sense.

David.