The DS2165Q ADPCM processor chip is a dedicated digital-signal-processing (DSP) chip that has been optimized to perform adaptive-differential pulse-code modulation (ADPCM) speech compression at three different rates. The chip can be programmed to compress (expand) 64kbps voice data down to (up from) either 32kbps, 24kbps, or 16kbps. The compression to 32kbps follows the algorithm specified by CCITT Recommendation G.721 (July 1986) and ANSI document T1.301 (April 1987). The compression to 24kbps follows ANSI document T1.303. The compression to 16kbps follows a proprietary algorithm developed by Dallas Semiconductor. The DS2165Q can switch compression algorithms on-the-fly. This allows the user to make maximum use of the available bandwidth on a dynamic basis. Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device may be simultaneously available through various sales channels. For information about device errata, click here: http://www.maxim-ic.com/errata. 1 of 17