1/8th power white noise ( or maybe sinewave ) IIRC.
I was pondering this actually but came to no conclusion. I wonder if the phase shift method also results in lower HF current when signal is present too ?
The only examples I've seen to date are simply ICs from TI. I'm sure TI have a reason to make them that way !
Might be interesting for a higher power discrete amp too.
Needs thinking about !
Graham
Harmonics of what? If you include 1X the frequency as a harmonic, then everything is harmonic. If not then the fundamental of the switching frequency is not a harmonic and yet it is the biggest problem from an EMI point of view.
No, this does not need to happen.
ASCII art:
+V---------O BTW, with fixed load by the speaker, pulse skipping may not likely toNo it doesn't see above.
that means nothing wrt EMI specs, which make you load up at some sort of worst-case levels, which probably aren't zero signal :)
and fet dV/dt noise wont change.
AIUI the real benefit of phase-shift modulation is that the switches run at just under 50% duty cycle, so simple xfmr gatedrives can be used, and ZVS is easy to obtain.
Cheers Terry
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