74HC942

MM74HC942 300 Baud Modem January 1988 MM74HC942 300 Baud Modem General Description The MM74HC942 is a full duplex low speed modem It provides a 300 baud bidirectional serial interface for data communication over telephone lines and other narrow bandwidth channels It is Bell 103 compatible The MM74HC942 utilizes advanced silicon-gate CMOS technology Switched capacitor techniques are used to perform analog signal processing Features Y Y Y Y Y Y Y Y Y Y www.DataSheet4U.com 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 dBm DEMODULATOR SECTION The demodulator incorporates anti-aliasing filters a receive filter limiter discriminator and carrier detect circuit The nine pole receive filter provides 60 dB of transmitted tone rejection The discriminator is fully balanced for stable operation Drives 600X at 0 dBm All filters on chip Transmit level adjustment compatible with universal service order code TTL and CMOS compatible logic All inputs protected against static damage g 5V supplies Low power consumption Full duplex answer or originate operation Analog loopback for self test Power down mode Applications Y Y Y Y Y Y Y Y Built-in low speed modems Remote data collection Rad...