• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

digital switch

Not open for further replies.


New Member

Im wondering if anybody knows of a simple digital switch that will connect 2 pins on a low input and put a huge resistance between the two on a high input (just a normal digital switch).

or is there a circuit that can do the same thing?

Its for an oscillator circuit operating at up to 1kHz so if a circuit is suggested, it probably should be relatively fast. thanks a lot.



New Member
Hi, the on resistance of the switch seems to be a huge problem. the circuit i am looking at making is for a voltage controlled oscillator, where a capacitor is connected to ground once the switch is closed and discharges. with a 100ohm resistance, the capacitor doesn't discharge.

any other idea's?


Active Member
You could use an N-channel FET as a switch, there are fet's out there with an Ron of only few milliohms. Problem with these is that when turned off; they have quite a large capacitiy (approx 1 or more nF) between drain and source wich might also be a problem (cause small signals will still get trough due to the capacitance)

only thing besides that would be a QS3384 bus switch (10 switches)
Ron is 4 to 5 ohm and capacitance is very small. But they're only available in small SMD packages and not so cheap (over here anyway).

Not open for further replies.

Latest threads

EE World Online Articles