Application of a switched-capacitor circuit to converting a two-wire to a four-wire hybrid function

ABSTRACT

A new switched-capacitor circuit using an integral feedback capacitor is proposed. A capacitor in a CR integrator which uses an operational amplifier is regarded as an information transmission element. By switching this capacitor from the input side to the output side periodically, a sampled-data transmission circuit is produced which has better frequency response than that of an ordinary integrator. The technique is shown applied to a solid-state two-wire to four-wire hybrid function in telephone communication.