bootstrap analog multiplexer

Nope, you just buy'em :-)

Supertex makes HV muxes:

Alternatively; attenuate, multiply and amplify. Whatever floats your boat.

Or just an inverting opamp and clamp the mux inputs to gnd.

t=2E

Thanks for your input.

The mux is at the (+) input of an op amp configured as a voltage follower. My design requires 1G=CE=A9 of input impedance minimum which would preclude resistor type attenuators. I am assuming that is what you were referring to. I may have better luck looking for an accurate "active" attenuator (?).

The Supertex devices in the previous post may be a good solution...I'll have to review the specs.

There's also the possibility of using optically-switched MOSFET switches, some of these are quite good for signals. You mention a 1G Zin requirement, what about I_leakage and capacitive-loading specs, anything there?

What are you working on?

This is an input circuit to a general purpose data acquisition board. The output of the analog multiplexer is buffered with a voltage follower (AD8512) in order to meet input requirements of 1G=CE=A9 input impedance and input leakage < 0.5=C2=B5A.

The output of the voltage follower then feeds a level shifter/ attenuator ckt that differentially drives a 24-bit ADC.

Thanks for the help.