Hello  rsgb,

  Some Class D LF / MF amps use a diode to DC restore the waveform
  after the FET driver chip to the gates. Why do they do this, I am
  thinking the negative part of the waveform would turn OFF the gate
  harder, assuming the positive part is adequate to turn the gates ON
  hard enough? Is there any point in using the modern FET's designed
  to have a negative rail to turn the gates off hard? Cree do the
  Wolfspeed ones with this feature. I have also noticed that with amps
  where the input to the driver is capacitively coupled adding a DC
  restoration diode makes the waveform pretty much exactly 50 / 50
  mark  space,  whereas without one this is not the case. Good idea to
  use these restoration diodes there? Thanks.

-- 
Best regards,
 Chris                          mailto:[email protected]