Message-ID: <5D2F677F.1090208@posteo.de>
Date: Wed, 17 Jul 2019 20:22:55 +0200
From: DK7FC <selberdenken@posteo.de>
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To: rsgb_lf_group@blacksheep.org
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Subject: Re: LF: DC restoration
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Hi Chris,

Maybe it helps to show a concrete schematic together with your question.
I find reverse diodes quite useless, at least when MOSFETs are used. It 
may be a different thing with bipolar transistors...

73, Stefan

Am 17.07.2019 15:38, schrieb Chris Wilson:
>
> 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.
>
>