Author Topic: What's this electronic symbol? (Read 1755 times)

LektroiD · « **on:** April 13, 2015, 02:00:26 pm »

I stumbled upon this unusual symbol whilst looking at some old schematics. I've never seen one of these before...

TimFox · « **Reply #1 on:** April 13, 2015, 02:03:58 pm »

Bi-directional switch: solid-state equivalent of a relay contact.

SeanB · « **Reply #2 on:** April 13, 2015, 03:56:15 pm »

Older symbol for a CMOS ( or NMOS in some older chips) transmission gate. Basically a digitally controlled switch that can pass any signal, digital or analogue, that falls within the supply rails to the chip with only a series resistance. The resistance will be poorly defined, but will be somewhere between 3R and around 700R, depending on the voltage applied to the gate while the digital control selects whether the gate is low resistance or very high resistance ( in the multi megohm range) so acting as a switch.