Your favourite self oscillating topology

Which self oscillating topology is your favourite ?

  • UcD (Universal Class D)

    Votes: 7 50.0%
  • Delta Sigma

    Votes: 5 35.7%
  • Hysteresis

    Votes: 2 14.3%

  • Total voters
Yeah! TLS272 is my integrator.


  • Class D Audio.GIF
    Class D Audio.GIF
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4047 is oscillating at 560KHz, and then main frequency switching is 280KHz. Tho anti phase outputs of 4047 are added at the integrator's output. It work pretty, in this moment I'm listen internet radio using this device powered from the yellow (+12) and blue (-12) of this ATX PS of this computer.
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...being some more specific on my comment above.
The hysteresis oscillator is usually seen with fixed hysteresis.
That's why I said none of them.
Comparing fixed hysteresis vs. UcD - I would prefer UcD.
Stepping to a dynamic hysteresis vs. UcD - I prefer dynamic hysteresis.

No experience on sigma delta - so I cannot vote for it.
Ok, but let's to agree that it is easily to eliminate or filter a narrow width frequency variation that a large one. I can say it as ham radio from 1987.
You can't notch filter a fixed frequency class D amplifier output - the carrier has harmonics which a notch won't take out, and secondly the carrier is modulated by the audio frequency. You're stuck with lowpass filtering.