matching n and p fets capacitances

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cct 1 has caps, based on the spec sheet, with equal value gate R's

cct 2 has a higher gate resistor for the n-device.

i not sure which setup to use.:confused:

cct 1.JPG

cct 2.JPG
 
does C4 need a series resistor?

i've read that c4 is a "feedforward" compensation cap, and as such may need an resistor in series with it.

i dont know if it needs one, and if it does what value it should be - any advice regarding this will be greatly appreciated.
 
A bit taxing to the amplifier as you need to run it pretty hot -- you place a trimmer in one of the gate circuits, say 500 ohms, set to mid-value. Using a square wave source, adjust the trimmer until the amplifier "slews" identically for the N and P channels. The square wave source would be about half the input voltage you would normally use for sine-wave testing.

Explained in page 16 of this application note from Texas Instruments:
http://www.ti.com/lit/an/snaa045a/snaa045a.pdf

You probably don't need the protection diodes for the Lateral Mosfets --

Jack
 
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