Description
The Quad ADPCM Transcoder is a low power, CMOS device capable of four encode and four decode functions per frame. Four 64 kbps PCM octets are compressed into four 32, 24 or 16 kbps ADPCM words, and four 32, 24 or 16 kbps ADPCM words are expanded into four 64 kbps PCM octets. The 32, 24 and 16 kbps ADPCM transcoding algorithms utilized conform to ITU-T Recommendation G.726 (excluding 40 kbps), and ANSI T1.303 - 1989.

FEATUREs
• Full duplex transcoder with four encode channels
   and four decode channels
• 32 kbps, 24 kbps and 16 kbps ADPCM coding
   complying with ITU-T (previously CCITT) G.726
   (without 40 kbps), and ANSI T1.303-1989
• Low power operation, 6.5 mW typical
• Asynchronous 4.096 MHz master clock operation
• SSI and ST-BUS interface options
• Transparent PCM bypass
• Transparent ADPCM bypass
• Linear PCM code
• No microprocessor control required
• Simple interface to Codec devices
• Pin selectable µ−Law or A-Law operation
• Pin selectable ITU-T or signed magnitude PCM
   coding
• Single 3.3 Volts power supply

APPLICATIONs
• Pair gain
• Voice mail systems
• Wireless telephony systems