If you mean about the advantae and the disadvantage there are so many thing here to rememder opamps if you use to say is the most basic design used for a long time, now this opamps is simply say, it is a transistors circuit design used in so many variety of appliances and it make the electronics appliances huge and bunch of parts and it' spend much power as we compare to the cmos, this bjt's maybe a high gain output and low gain input but it is just as 50% of operation if we compare it to cmos, because cmos is low power input and high current output and it is used nowaday to conserve elecric power it is because it operates only for what is been use to it and it is made cheapest and smallest to .000001 nanometers as the bjts is made huge and this cmos is also used nowaday to make the high technology as cellphone and ipod as those bjt's cannot fit. to that types of gadgets. using cmos today make life so easy but way say bjt's is the things why this cmos born but man makes his life effient to what he is today.
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