描述 Description

The HC-55564 is a half duplex modulator/demodulator CMOS intergrated circuit used to convert voice signals into serial NRZ digital data and to reconvert that data into voice. The conversion is by delta-modulation, using the Continuously Variable Slope (CVSD) method of modulation/demodulation.

特性 Features

? All Digital

? Requires Few External Parts

? Low Power Drain: 1.5mW Typical From Single 4.5V To 6V Supply

? Time Constants Determined by Clock Frequency; No Calibration or Drift Problems: Automatic Offset Adjustment

? Half Duplex Operation Under Digital Control

? Filter Reset Under Digital Control

? Automatic Overload Recovery

? Automatic “Quiet” Pattern Generation

? AGC Control Signal Available

Applications

? Voice Transmission Over Data Channels (Modems)

? Voice/Data Multiplexing (Pair Gain)

? Voice Encryption/Scrambling

? Voicemail

? Audio Manipulations: Delay Lines, Time Compression, Echo Generation/Suppression, Special Effects, etc.

? Pagers/Satellites

? Data Acquisition Systems

? Voice I/O for Digital Systems and Speech Synthesis Requiring Small Size, Low Weight, and Ease of Reprogrammability

? Related Literature - AN607, Delta Modulation for Voice Transmission