74HC942
Description
The MM74HC942 is a full duplex low speed modem It provides a 300 baud bidirectional serial interface for data munication over telephone lines and other narrow bandwidth channels It is Bell 103 patible The MM74HC942 utilizes advanced silicon-gate CMOS technology Switched capacitor techniques are used to perform analog signal processing
Features
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.. MODULATOR SECTION
The modulator contains a frequency synthesizer and a sine wave synthesizer It produces a phase coherent frequency shift keyed (FSK) output LINE DRIVER AND HYBRID SECTION The line driver and hybrid are designed to facilitate connection to a 600X phone line They can perform two-to-fourwire conversion and drive the line at a maximum of 0 d Bm DEMODULATOR SECTION The demodulator incorporates anti-aliasing filters a receive filter limiter discriminator and carrier detect circuit The nine pole receive filter provides 60 d B of transmitted tone rejection The discriminator is fully balanced for...
