Analog multiplexer

DETAILED DESCRIPTION Accordingly, the object of this invention is to provide an analog multiplexer of simple construction, which is highly accurate, has a reduced difference between the input and output signals, and is quick to respond.
According to this invention, there is provided an analog multiplexer which comprises at least one emitter follower differential amplifier composed of first and second bipolar transistors the emitters of which are connected in common, an analog signal input terminal connected to the base of the first bipolar transistor, an analog output terminal connected to the base of the second bipolar transistor, a load composed of a current mirror connected between the collectors of the first and second bipolar transistors and one terminal of a power source, a switch circuit with one terminal connected to the common junction of the emitters of the first and second bipolar transistors and the other terminal connected to the other terminal of the power source through a first constant-current surce, a control circuit for controlling the switch circuit, an output circuit connected between the analog output terminal and the one terminal of the power source, and a second constant-current source connected between the analog output terminal and the other terminal of the power source.