Integrierte PCM-Codec-Schaltung für ein Vermittlungssystem

An integrated PCM-CODEC circuit including a plurality of PCM subscriber lines consisting of a SLIC for interfacing a telephone line with a switching system, an impedance conformer and a PCM-CODEC, a common bus for transferring a telephone signal into or from a subscriber according to the time division rule for the timing of telephone line use, a telemetering signal source and a (synchronization signal for controlling portion of the telephone call called by the n'th subscriber. The PCM-CODEC circuit includes a buffer, a signal selector, an applied gain controller, an anti-aliasing filter, a telemetering signal filter, a BPF, a coder, a decoder, a LPF, a received-gain controller, a smoothing filter, an operational amplifier and a telemetering gate.