Transistor as switch

[hilalgceylan]

We need to obtain 5 different transimpedance gain by using a transistor as a switch over the Cadence Simulation Environment. We have capacitor and resistors values, however we don't know how to use a transistor as a switch in Cadence. Should we give DC Voltage value to every transistor, or is there any easy way that we can use them directly?

Please, help..

 

[frankrose]

Too much confusion, I think nobody will understand your real issue. Please, rephrase the problem and add some pictures if possible, visual aid can help a lot.

 

[LvW]

Are you aware that a bipolar transistor can just "switch" a voltage on/off ?
When you want to "switch" a signal - like a relay - you must use a FET.

 

[BradtheRad]

See the thread below in regard to switching in various resistor values to achieve different levels of gain. My post has a schematic depicting a 4066 IC (quad bilateral switch).

www.edaboard.com/threads/current-multiplexer-for-values-between-100na-10na.330753/

 

[hilalgceylan]

Are you aware that a bipolar transistor can just "switch" a voltage on/off?
When you want to "switch" a signal - like a relay - you must use a FET.

Thanks for the information. We used NMOS transistors as switches. However, it causes stability to decrease.

 

[KlausST]

Hi,

However, it causes stability to decrease.

from all your posts above.... please tell me what can be (in-)stable?

As already recommended in post#2: show your circuit.

Klaus