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PSS for characterising switch mode amplifiers? (Read 3337 times)

Prabhu Junior Member Offline Posts: 23	PSS for characterising switch mode amplifiers? Aug 27^th, 2007, 3:21am Is PSS analysis suitable for analysing switch mode amplifiers like class D PAs? Thanks, Raja
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Ken Kundert

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Silicon Valley

Re: PSS for characterising switch mode amplifiers?
Reply #1 - Aug 27^th, 2007, 10:03am

PSS and its small-signal minion (PAC, PXF, PSTB, etc) can be used on switching amplifiers as well as switching regulators. PAC & PXF can be used to find things like small-signal output impedance and supply rejection. PSTB can be used to measure the loop gain of the amplifier. PNoise can be used to determine the noise performance. One can also use QPSS to measure distortion and Envelope Following to speed up a long transient analysis.

What is it that you are trying to measure?

-Ken

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Prabhu Junior Member Offline Posts: 23	Re: PSS for characterising switch mode amplifiers? Reply #2 - Aug 28^th, 2007, 3:03am Thanks for the reply Ken. I need to characterise the distortion and stability performance of a switching (pwm) amplifier in feedback. I was not sure whether to use PSS since it is not recommended for a similar delta-sigma modulator system. Raja
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Ken Kundert Global Moderator Offline Posts: 2386 Silicon Valley	Re: PSS for characterising switch mode amplifiers? Reply #3 - Aug 28^th, 2007, 2:04pm A prerequisite for use of PSS is that your circuit have a periodic solution. Sigma-Delta converters do not have periodic solutions. If your amplifier uses delta-sigma modulation then you probably cannot use PSS. For stability use PSS/PSTB. For distortion use QPSS/QPAC. -Ken
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