I'm designing a circuit that would switch between stereo-jack inputs. Source audio would be plugged into one end, and on the other two ends, two different audio outputs. I want to be able to switch between one of the two outputs.

Physically, I know how to do this, it is very simple using a double throw switch.

However, if I want to do this digitally, using a micro-controller board to control the switching, what type of component would I use?

I know that the digital equivalent of a SPST is an NPN-transistor. What is the digital equivalent of DT switch? Any support multiple poles?

A poor diagram of what I want to do.


  • \$\begingroup\$ For audio I'd go for a relay. \$\endgroup\$ – jippie Apr 21 '14 at 6:53
  • \$\begingroup\$ I second that with DPDT latching relays 50mW coil pewa.panasonic.com/assets/pcsd/catalog/tx-s-catalog.pdf \$\endgroup\$ – user38637 Apr 21 '14 at 12:02
  • \$\begingroup\$ Note that you probably don't want to switch the sleeve, lest you introduce a Pin 1 problem into your circuit \$\endgroup\$ – ThreePhaseEel Oct 12 at 14:21

What you're looking for is an analog switch. The control lines are selected via digital IO but the signals passing through are analog.

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    \$\begingroup\$ While I would also go for an analog switch in the first instance, if for some reason they are unsuitable (e.g. biasing problems, or problems with the series resistance of a few hundred ohms they typically exhibit) then a DP3T relay might be more suitable. \$\endgroup\$ – markt Apr 21 '14 at 4:12
  • \$\begingroup\$ @markt - There are ~2Ω series resistance analog switches. Or you could always buffer the signal after the analog switch. \$\endgroup\$ – Connor Wolf Apr 21 '14 at 14:15
  • \$\begingroup\$ @ConnorWolf All true, but a fair bit of extra electronics. A relay & driver is very minimalist. \$\endgroup\$ – markt Apr 22 '14 at 9:35
  • \$\begingroup\$ Thanks everyone for your insightful answers! I think I will use a double-throw relay. They seem to be pretty easy to find. \$\endgroup\$ – cdahmedeh Apr 24 '14 at 6:48

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