[moved] I want to improve my dexterity with both PMOS and NMOS

[sneha rayala]

Hi ,
I have done designing of two stage opamp and folded cascode opamp etc(Learnt from allen holberg textbook) using nmos stages but I always struggle doing with pmos input stages(considering all the equations for icmr +,icmr- etc change ) . how do I overcome this any material which focuses on both . kindly please elaborate

 

[BradtheRad]

I suppose you know about the trick of reversing emitter arrows on NPN transistors, thus reversing PN junctions, turning them into PNP? (Apply similar action to Nmos & Pmos.)

And change the sign on supply rails?

As for 0V ground, designate it as a centerline between the supply rails, or as 1/2 supply voltage, depending on your setup.

The long-tail pair (differential detector) has the tail resistor (or tail component, or current source) near the positive supply.
Likewise note that a P-type long-tail pair has its emitters or sources (of current not electrons) facing the positive supply.