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¡ Semiconductor

MSM7580

¡ Semiconductor

MSM7580

ITU-T G.721 ADPCM TRANSCODER

GENERAL DESCRIPTION

The MSM7580 is an ADPCM transcoder which is used by the new digital cordless system. It

converts 64 kbps voice PCM serial data to 32 kbps ITU-T G.721 ADPCM serial data, and vice

versa.

This device consists of two systems with full-duplex voice data channels and a data-through

mode.

The MSM7580 provides cost effective solutions for digital cordless office telephone systems

which are incorporated into PABXs and for the public base stations which are connected to the

central office through digital PSTNs.

FEATURES

• Conforms to ITU-T G.721

• Built-in Full-duplex Transcoder with Two Data channels

• PCM companding Law: A-law/

µ-law selectable

• Synchronized Operation between coder and decoder, and between two channels.

• Serial PCM Data Transmission Speed: 64 kbps to 2048 kbps

• Serial ADPCM Data Transmission Speed: 32 kbps to 2048 kbps

• Hardware Reset – ITU-T G.721 Optional Reset – for each channel

• Power Down Control for each channel

• Decoder (ADPCM Æ PCM ) MUTE Mode and PAD Mode for each channel

• ADPCM Data-through Mode

• Capable of time slot conversion

• Special ADPCM Input Data Code (”0000”) Detector for each channel

• Master Clock Signal : Not necessary

• Power supply voltage/Consumption current :

+5 V

±10%, 2.5 mA/channel

• Package :

28-pin plastic SOP (SOP28-P-430-1.27-K) (Product name : MSM7580GS-K)

E2U0031-39-61

This version: Jun. 1999

Previous version: Aug. 1998