I am designing a wide ICMR diff amp. To realize it, I made pmos diff pair as well nmos diff pair. The idea here is, for lower values of ICMR, pdif pair will conduct and for higher values of ICMR ndiff pair . My question is, from the outputs of pdiff pair and ndiff pair how should I make the single ended output.

-Bharat

there's tons of good papers about this. the guys at the delft institute publish great stuff. type huijsing in the ieee search and you'll see some good amplifiers papers in there that will solve your problem.