E2U0060-18-84
¡ Semiconductor
MSM7731-01
¡ Semiconductor
Multifunction PCM CODEC (Voice Signal Processor)
This version: Aug. 1998
MSM7731-01
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Pr
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GENERAL DESCRIPTION
The MSM7731 is an LSI device developed for portable, handsfree communication with built-in
line echo canceler, acoustic echo canceler, and transmission signal noise canceler. Built-in to the
voice signal interface is a linear CODEC for the analog interface on the acoustic-side, and a linear
CODEC for the analog interface on the line-side. On the line-side, in addition to the analog
interface, there is also a
m-law
PCM/16-bit linear digital interface.
Equipped with gain and mute controls for data transmission and reception, a
m-law
PCM/16-
bit linear digital interface for memo recording and message output, and transfer clock and sync
clock generators for digital communication, this device is ideally suited for a handsfree system.
FEATURES
• Single 3 V power supply operation (2.7 V to 3.6 V)
• Built-in 2-channel (line and acoustic) echo canceler
Echo attenuation : 35 dB (typ.)
Cancelable echo delay time :
Line echo canceler + acoustic echo canceler : Tlined = 27 ms (max.),
Tacoud = 59 ms – Tlined (max.)
Acoustic echo canceler only :
Tacoud = 59 ms (max.)
• Built-in transmission signal noise canceler
Noise attenuation: 13 dB (typ.) for white noise
40 dB (typ.) for single tone
• Built-in 2-channel CODEC
Synchronous transmission and reception enables full duplex operation
• Built-in analog input gain amp stage (max. gain = 30 dB)
• Analog output configuration: Push-pull drive (can drive a 1.2 kW load)
• Built-in transmit slope filter
• Digital interface coding formats:
m-law
PCM, 16-bit linear (2's complement)
• Digital interface sync formats:
Normal-sync, short-frame-sync
• Built-in digital transmission clock generators
Sync clock (SYNC):
8 kHz output
Transmission clock (BCLK): 64 kHz output (m-law PCM)/128 kHz
output (16-bit linear)
• Digital transmission rate
External input:
64 kbps to 2048 kbps
Internal generation:
64 kbps (m-law PCM)/128 kbps (16-bit linear)
• Fixed digital interface sync clock (SYNC) enables automatic power-down
• Master clock frequency: 19.2 MHz
Compatible with crystal oscillator and crystal
• Low power consumption
Operating mode:
typ. 105mW (when V
DD
= 3.0 V)
Power-down mode:
typ. 0.3mW (when V
DD
= 3.0 V)
• Control by both the serial microcomputer interface and parallel port is possible
• Transmit/receive mute function, transmit/receive programmable gain setting
• Package: 64-pin plastic QFP (QFP64-P-1414-0.80-BK) (Product name: MSM7731-01GA)
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