ADG601: Digital input from a FET

Document created by analog-archivist Employee on Feb 23, 2016
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I'm intending to use the ADG601 switch in a new design. The switch will be
powered from +/-5V supply rails ie. Vdd=+5,Vss=-5V. I ideally wish to drive the
ADG601 digital input from a FET (drain) and was intending to use a high value
pullup resistor to Vdd at the FET drain. Do you see any issue in doing this?
I'm not concerned about switching speed.


I assume that what you want to do is to set the HIGH logic for the control
input using a high value pull-up while the LOW logic will be set using the FET
which will pull the control input to GND. If that is the case, I don't see any
problem, but you should be aware that having an excessively high pull-up could
make the control input of the switch more susceptible to pick-up noise as with
any CMOS logic device.