MICROCHIP MT9122APR1

The MT9122 Voice Echo Canceller implements a cost effective solution for telephony voice-band echo cancellation conforming to ITU-T G.165 requirements. The MT9122 architecture contains two echo cancellers which can be configured to provide dual channel 64 millisecond echo cancellation or single channel 128 millisecond echo cancellation. The MT9122 supports ITU-T G.165 or G.164 tone disable requirements. The MT9122 operates in two major modes: Controller or Controllerless. Controller mode allows access to an array of features for customizing the MT9122 operation. Controllerless mode is for applications where default register settings are sufficient.

• Dual channel 64 ms or single channel 128 ms echo cancellation
• Conforms to ITU-T G.165 requirements
• ITU-T G.165/G.164 disable tone detection supported on all audio paths
• Narrow-band signal detection
• Programmable double-talk detection threshold
• Non-linear processor with adaptive suppression threshold and comfort noise insertion
• Offset nulling of all PCM channels
• Controllerless mode or Controller mode with serial interface
• ST-BUS or variable-rate SSI PCM interfaces
• Selectable μ/μ -Law ITU-T G.711; μ/μ -Law Sign Mag; linear 2’s complement
• Per channel selectable 12 dB attenuator
• Transparent data transfer and mute option
• 19.2 MHz master clock operation

• Wireless Telephony
• Trunk echo cancellers