The CMX860 is a flexible, low power Telephone Signaling Transceiver IC designed for use in a wide range of line-powered telephone equipment. The IC combines the functions of a DTMF encoder and decoder, V.23 modulator and demodulator plus call progression circuitry with analog switching between line and phone interfaces. Ring detection, local phone offhook detection, and a relay for line hook-switch operation are also provided under the control of C-BUS. The ring and hook detectors operate while the remainder of the IC is powersaved, generating an interrupt to wakeup the host C when further processing or signaling is required. All on-chip functions and switching arrangements are controlled via a serial bus (C-BUS). The CMX860 is designed to operate at 2.7V and utilizes MX-COM's low power DTMF decoder and V.23 modem technology. The CMX860 is available in 28-pin SSOP (CMX860D6) and 28-pin SOIC (CMX860D1) packages.