|To:||"[email protected]" <[email protected]>|
|Subject:||Re: LF: MOSFET gate resistors question|
|From:||Andy Talbot <[email protected]>|
|Date:||Sun, 2 Jun 2019 15:50:44 +0100|
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Teh 4k7 on the gate is not a pull down. I assume it is associated with gate drive via a capacitor and diode to give DC restoration. A safe way of driving FETs to prevent them beoing switched permanantly on if a driver or logic circuit goes haywire. All the resistor does is prevent the mean DC component on the gate from floatiing off to some arbitrarily high value.
The gate series resistor is there to prevent spurious ringing and high frequency oscillations. Using a decent driver chip and short leads / tracks it shouldn't be necessary, but doesn't do any harm.
Just use a good driver chip capable of driving the gate cap of your FET, If it doesn't, itself, have a Schmitt input, make sufre its drive with a sharp edged logic drive waveform. Perhaps from a Schmitt gate.
On Sun, 2 Jun 2019 at 14:46, Chris Wilson <[email protected]> wrote:
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