ANALOG MULTIPLEXER

PURPOSE:To remove DC level fluctuation at the time of switching, by respectively coupling the emitter of transistors for current switching and also utilizing plural number of differential relays and - load resistance in common. CONSTITUTION:When voltage (emitter reference voltage of transistor 32 + double of connection voltage between base and emitter) is impressed to a control input terminal 41, transistor (TR)22, 32 for current switching are interrupted. As a result, collctor current of TR27 is supplied to TRs20, 21 for differential amplification through TR17 for current switching. Hereupon at the differential output terminals 30 and 40, signals inputted from input signal terminals 36 and 36 centering the bias voltage are appeared. Successively, reset the voltage of the control input terminal 41 to the initial voltage and add the voltage to a control input terminal 42. As a result, said TR17 and TR32 are interrupted and the collector current of TR27 is supplied to TR25 and TR26 for differential amplification through TR22 for current switching.