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In datasheet for MOSFET driver ZXGD3003E6TA is following typical application circuit:

enter image description here

What should be the value of circled resistor? I did not find any reference in documentation.

Datasheet link: http://www.mouser.com/ds/2/115/ZXGD3003E6-77316.pdf

ToKra
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    Good question. Looks like two transistors in a box, so I'd just assume it's a weakish pull-down. – pipe Oct 15 '16 at 11:55

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Consider your input, if you have a microcontroller driving that pin the resistor must be high enough so that MCU can drive current thru that resistor. It also must be low enough to be useful, so that gate is low when floating.

Personally i would put a 10k or similar value resistor there.

Basically here is longer answer to the guestion:

Calculating the pulldown resistance for a given MOSFET's gate

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jalaffo
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    He's not driving a MOSFET, he's driving a _MOSFET driver_. – pipe Oct 15 '16 at 12:05
  • ...which includes a mosfets ;). The driver has a totem pole inside made of most llikely of mosfets. Besides it doesnt matter does that driver exist or not, because the capacitive gate is anyway there which cant be floating. – jalaffo Oct 15 '16 at 12:08
  • The device draws quite a substantial current on its input, several mA, so it's unlikely to include MOSFETS. The input capacitance is unspecified in the datasheet. – pipe Oct 15 '16 at 12:13
  • Mosfet can draw several amps to its gate. I guess afterall that it includes BJT's inside as the datasheet says: "Fast switching emitter-follower configuration • 2ns propagation delay time • 19ns rise/fall time, 1000pF load" – jalaffo Oct 15 '16 at 12:18
  • Yes the switching time test circuit gives it away; the input contains NPN/PNP totem pole, however the bottom line is that the input pin cant be left floating, and that is why the resistor is there and OP asks about its value. – jalaffo Oct 15 '16 at 12:24
  • Well, technically push-pull, not totem-pole. Crappy datasheet though, not including a proper internal diagram. I would say showing a series resistor is more important than the pull-down. – AngeloQ Mar 13 '17 at 13:23