SPDT Switch using N-JFETs

[Yoa01]

Hi all,

So I want to make a voltage-controlled SPDT switch using N-channel JFETs. I've tried every idea I can think of, save ditching the idea and using VCS ICs. In essence what I want it to do is use a square wave to switch between two inputs to a central output. It would also be cool if it were bi-directional; that is, switch one input between two outputs.

And yes, I'm essentially try to do this, just differently.

Thanks.

 

[GreenGiant]

Why not just get an N-Channel and a P-Channel, that way it will switch when the voltage goes low and high without any other circuitry

 

[Yoa01]

That... that sounds pretty awesome! I'll have to wait for my p-channels to come in, but until then can you tell me how to connect the two to make them do that? I have literally no experience with p-channel JFETs.

 

[Harald Kapp]

Look at the interior circuit of an integrated analog switch. Or read this description (recommended).

 

[Yoa01]

Hm... that document was helpful, but it seems I either need MOSFETs or I'm just not looking hard enough! Sadly, it seems that just about every switch IC is see (lol) shows just a normal switch

 

[BobK]

What is wrong with analog switch IC's?

Bob

 

[Yoa01]

Oh nothing! I was just hoping to use parts I already have (and on the way from Futurlec). I mean if it gets right down to it I'm sure I can get the switch I need for, what, $.20? lol