MICROCHIP ZL38010DCE1

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. Switching, on-the-fly, between 32 kbps and 24 kbps ADPCM, is possible by controlling the appropriate mode select (MS1 - MS6) control pins. All optional functions of the device are pin selectable allowing a simple interface to industry standard codecs, digital phone devices and Layer 1 transceivers. Linear coded PCM is provided to facilitate external DSP functions.

• 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

• Pair gain
• Voice mail systems
• Wireless telephony systems