DESIGN OF DIFFERENTIAL CMOS OUTPUT BUFFER

Abstract

Today science has come up very fast and also the requirement of human being. Every one wants to be fast. We want that our computer should copy full pen drive or USB (Universal Serial Bus) into the hard disk in a while. But it is taking so much time. On which parameter this delay or time depends? Does it depends on internal architecture of USB or hard disk or is it depends on processors speed? In fact it depends on the parasitics of pad and communication link. Input /Output devices increases the drive strength of the signal up to certain level so that it will little bit compensate the parasitics of the pad. Again if we are transmitting higher voltage then we cant have higher frequency of operation. But if we are using low voltage for transmission then noise ca easily corrupt our signal. In differential design we are taking difference of two voltages, which are almost equally affected by noise. So, we can use low voltage for transmission and hence higher frequency of operation. Therefore for all the design where higher speed is required differential design is used.