active resistance with NPN transistors

[azerty1]

Hello everyone,
I'm looking for active resistance simulators circuit based on NPN transistors.
Can you help me in this search?
Thank you

 

[FvM]

BJT are non-linear components by nature, so you can at best approximate a linear resistor charactericstic within a certain range. Or create the linear characteristic with the help of a feedback loop.

A detailed parameter specification would be the first step.

 

[LvW]

Hello everyone,
I'm looking for active resistance simulators circuit based on NPN transistors.

As you probably know - a JFET is able to provide a resistive channel around the origin (for both current directions).
Do you want to realize something similar with npn transistors ? This is not possible.
More than that, you should tell us if you want to realize a static or (only) a dynamic/differential resistance?

 

[azerty1]

I read in literature that they are resistance circuit with CMOS transistors, but i work in a project with NPN transistors, so i need to replace my passive resistance with others active.

 

[FvM]

As far as 'm aware of, there's no useful circuit with BJT acting as resistive active load. The undistorted voltage range is limited to a few 10 mV.

 

[LvW]

As far as 'm aware of, there's no useful circuit with BJT acting as resistive active load. The undistorted voltage range is limited to a few 10 mV.

I think, there are applications where the collector emitter path of a well biased BJT acts as a load resistance for another transistor - however, it is a dynamic resustance only (and not a kind of "ohmic" resistor).