Hades logoHades applet banner
CMOS transmission-gate multiplexer

applet icon

The image above shows a thumbnail of the interactive Java applet embedded into this page. Unfortunately, your browser is not Java-aware or Java is disabled in the browser preferences. To start the applet, please enable Java and reload this page. (You might have to restart the browser.)

Circuit Description

This circuit demonstrates the basic transmission-gate multiplexer. Click the input switches or type the 's', 'a', 'b' bindkeys to control the circuit.

The idea behind this circuit is to use two transmission-gates as simple switches to propagate either input A or input B directly to the output. The extra inverter generates the inverse of the SEL select input. While the upper transmission-gate is activated by SEL, the lower transmission-gate is activated by !SEL, due to the wiring of their control (gate-) inputs.

When SEL is low, only the lower transmission-gate is conducting (because !SEL is connected to its n-channel and SEL to its p-channel transistor gate inputs), while the upper transmission-gate is non-conducting. As a result, the value of A is passed through to the output of the multiplexer.

When SEL is high, the upper transmission-gate is activated, while the lower transmission-gate is non-conducting. Therefore, the value of B is passed through to the multiplexer output.

Print version | Run this demo in the Hades editor (via Java WebStart)
Usage | FAQ | About | License | Feedback | Tutorial (PDF) | Referenzkarte (PDF, in German)
Impressum http://tams-www.informatik.uni-hamburg.de/applets/hades/webdemos/05-switched/40-cmos/mux-tgate.html