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.
-- -- kensmith@rahul.net forging knowledge
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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