Codec/Modem Juggles Multiple Standards

Fashioned for use in telemetry and telephone-based information systems, the CMX865 DTMF codec and FSK modem IC offers multi-standard signalling capabilities. The codec exhibits reliable immunity to falsing on voice and is coupled with a high-performance V.23 FSK modem. Overall, the device is compatible with either 2- or 4-wire telephone installations, providing a ringing/line reversal signal detector input and a relay-drive output. A full set of standard DTMF tones and signalling tones is available, including modem call/answer tones and call-progress tones. Alternatively, encode and decode signalling functions can be software configured to generate and decode user-selectable single- and dual-tone signals. Other features include programmable DTMF Tx, a selectable 11.0592-MHz or 12.288-MHz oscillator, asynchronous and synchronous data modes with V.14 support, Rx/Tx USART functions, 3-state Tx line drive, ring and line reversal detector, hook-switch output, and a C-BUS serial interface. Price is $1.19 each/100,000. CML MICROCIRCUITS INC., Winston-Salem, NC. (800) 638-5577.