1
\$\begingroup\$

I'm working on a circuit with a non-inverting amp and I would like to switch between two reference voltages, both with low output impedance.

So in effect i want something like this:

schematic

simulate this circuit – Schematic created using CircuitLab

One thing: R1 is done using LM385 low power reference voltage, so voltage between anode and katode of D1 is 1.2V. Output impedance of U1 is about 300 ohms.

I stumbled upon a thing called analog multiplexer and I think that it would suit this purpose quite OK. I would like to build it using basic components instead of buying IC. I thought about using JFETs, but would it make sense for such small voltages?

Please help!:)

\$\endgroup\$
10
  • \$\begingroup\$ Please post the schematic of the circuit you're proposing to use to implement an analog multiplexer using JFETs. \$\endgroup\$
    – The Photon
    Commented May 14, 2017 at 15:07
  • \$\begingroup\$ In principle, yes you can. Are you as far along as having a circuit yet? If so, please edit your question and add the circuit to it. Or are you right at the start, just wondering if it's even a good idea? Thanks. \$\endgroup\$
    – TonyM
    Commented May 14, 2017 at 15:23
  • \$\begingroup\$ Why use two references when apparently one would suffice with a pot divider? \$\endgroup\$
    – Andy aka
    Commented May 14, 2017 at 15:52
  • \$\begingroup\$ @Andyaka Alright, I added more detailed schematic:) It is a part of a more complex circuit. What I need right now is just to make this mux, preferably using basic ocmponents such as JFETs:) I'm pretty much sure that it is a good idea. Is it possible? \$\endgroup\$
    – Em Ka
    Commented May 14, 2017 at 15:55
  • \$\begingroup\$ I think the best idea is use a chip. \$\endgroup\$
    – Andy aka
    Commented May 14, 2017 at 16:03

0

Reset to default

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.