Doubts on Equivalent Circuits

[raju_kambar]

Field Effect Transistors group, Which is consisting of following transistors.

1) JFET
2) MESFET,HEMT
3)MOSFET,
4)NMOS,PMOS,CMOS
5)Memories
6)CCD

My question is, equivalent circuit of pHEMT and MOSFETs are different or equivalent circuit of pHEMT and MOSFET are same.

Is FET equivalent circuit same for JFET,MESFET, pHEMT,EHEMT, MOSFET,NMOS,PNOS,CMOS.
or
Each different transistors(JFET,MESFET,HEMT,MOSFET,NMOS,PMOS,CMOS) which comes in the FET groups are different equivalent circuits or same equivalent circuit for all.

Can you clear my above queries.

 

[Audioguru]

In addition to the different polarities of N-channel and P-channel Fets, some are depletion-mode and others are enhancement-mode.

Cmos is simply N-channel and P-channel Fets combined together in a circuit.

 

[raju_kambar]

In addition to the different polarities of N-channel and P-channel Fets, some are depletion-mode and others are enhancement-mode.

Cmos is simply N-channel and P-channel Fets combined together in a circuit.

Sorry, from your answer, I didn't clear my doubts.
Can you anybody elaborately answer to my doubts in the posting #1.

 

[FvM]

First obvious comment: CMOS, memories, CCD aren't "transistors", they are complex circuits comprised of at least two, usually many individual transistors.

Secondly there are different kinds of equivalent circuits, depending on the equivalence you're interested in. You have e.g. small signal versus large signal equivalent circuit, and different forms for specific problems.

Some types of equivalent circuits might be applicable to all transistors or even all two-port amplifier devices, others are more specific.

 

[Audioguru]

A Fet is simply a voltage-controlled resistance with a VERY simple equivalent circuit.

The types of Fets and their differences are described in Google. You can also see differences in their datasheets.
If you read and understand Google and the datasheets then there will be no doubts.