Programmable IC CMX138A

ASICanalog

The CMX138A is a half-duplex audio scrambler and sub-audio signalling processor for analogue two-way radio applications. This makes it a suitable device for the leisure radio markets (FRS, MURS, PMR446 and GMRS). This device provides a user programmable frequency inversion audio scrambler with compander and pre/de-emphasis – performing simultaneous processing of sub-audio and in-band signalling. Other features include: an auxiliary ADC channel and an auxiliary DAC interface (with optional RAMDAC) to facilitate transmitter power ramping. The device has flexible powersaving modes and is available in a 28-pin (E1) TSSOP package. This enhanced pin-compatible IC supersedes the CMX138 Programmable Audio Scrambler Full Audio-band Processing: – Pre and De Emphasis – Compander – Scrambler – Selectable 2.55 and 3.0 kHz Filters Auxiliary ADC and DAC C-BUS Serial Control/Data Interface to Host µController Two x Analogue Inputs (Mic. and Discriminator) Selectable Audio Processing Order CTCSS and DCS Sub-Audio Signalling Programmable In-band Tone Encoder and Decoder Auxiliary System Clock Output Single-point Modulation Tx Output Flexible Powersave Modes