DS2165

16/24/32kbps ADPCM Processor

Viewing:

Overview

Compresses/expands 64kbps PCM voice to/from either 32kbps, 24kbps, or 16kbps
Dual, fully independent channel architecture; device can be programmed to perform either:
- two expansions
- two compressions
- one expansion and one compression
Interconnects directly to combo-codec devices
Input to output delay is less than 375µs
Simple serial port used to configure the device
On-board time-slot assigner-circuit (TSAC) function allows data to be input/output at various time slots
Supports channel associated signaling
Each channel can be independently idled or placed into bypass
Available hardware mode requires no host processor; ideal for voice storage applications
Backward-compatible with the DS2167 ADPCM processor chip
Single +5V supply; low-power CMOS technology
Available in 28-pin PLCC
3V operation version is available (DS2165QL)

The DS2165 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 DS2165 can switch compression algorithms on-the-fly. This allows the user to make maximum use of the available bandwidth on a dynamic basis.