The CMX860 is a flexible, low-power Telephone Signalling 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 / Bell 202 modulator and demodulator plus call progression circuitry with analogue switching between line and phone interfaces. Ring detection, local phone off-hook detection and a relay driver for line hook-switch operation are also provided under the control of 'C-BUS'. The ring and hook detectors operate whilst the remainder of the IC is powersaved, generating an interrupt to wake-up the host C when further processing or signalling 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 utilises CML's low power DTMF decoder and V.23 / Bell 202 modem technology. It is available in 28-pin SOIC (D1), TSSOP (E1) and SSOP (D6) packages.