58 and 60 and the current source 58 functions in the conventional manner each branch of the differential amplifier experiences opposite current conductivity characteristics in response to differential drive signals applied at the input terminals 30 and 32 an increasing signal at terminal 30 will result in an increasing signal the source terminal 44 of transistor 36 which is also applied to the gate terminal of the transistor 56 a corresponding decreasing signal at the terminal 32 will result in a decreasing signal at the source terminal 46 of transistor 38 which is also applied to the gate terminal of the transistor 60 transistor 56 becomes more conductive and transistor 60 becomes less conductive the connected p channel transistors 54 and 56 of the two branches of the differential amplifier also become more conductive and less conductive respectively the constant current characteristics of the current source 62 divide the current between the two branches of the differential amplifier when the branch formed by transistors 54 and 56 conducts more current less current is available to be conducted through the branch formed by transistors 58 and 60 the constant current characteristics of the source 62 further ensure that the differential drive signals applied to the transistors 56 and 60 result in the equal and opposite effect in the two branches of the differential amplifier of course the opposite effect occurs from a relatively opposite levels of the differential.