ZL50234

• Independent multiple channels of echo cancellation; from 8 channels of 64ms to 4 channels of 128ms with the ability to mix channels at 128ms or 64ms in any combination
• Independent Power Down mode for each group of 2 channels for power management
• Fully compliant to ITU-T G.165, G.168 (2000) and (2002) specifications
• Passed AT&T voice quality testing for carrier grade echo cancellers.
• Compatible to ST-BUS and GCI interfaces with 2Mb/s serial PCM data
• PCM coding, /A-Law ITU-T G.711 or sign magnitude
• Per channel Fax/Modem G.164 2100Hz or G.165 2100Hz phase reversal Tone Disable
• Per channel echo canceller parameters control
• Transparent data transfer and mute
• Fast reconvergence on echo path changes
• Fully programmable convergence speeds
• Patented Advanced Non-Linear Processor with high quality subjective performance
• Protection against narrow band signal divergence and instability in high echo environments
• 0 dB to -12 dB level adjusters (3 dB steps) at all signal ports
• Offset nulling of all PCM channels
• 10 MHz or 20 MHz master clock operation
• 3.3 V I/O pads and 1.8V Logic core operation with 5-Volt tolerant inputs
• IEEE-1149.1 (JTAG) Test Access Port
• ZL50232, ZL50233, ZL50234 and ZL50235 have same pinouts in both LQFP and LBGA packages

The ZL50234 Voice Echo Canceller implements a cost effective solution for telephony voice-band echo cancellation conforming to ITU-T G.168 requirements. The ZL50234 architecture contains 4 groups of two echo cancellers (ECA and ECB) which can be configured to provide two channels of 64 milliseconds or one channel of 128 milliseconds echo cancellation. This provides 8 channels of 64 milliseconds to 4 channels of 128 milliseconds echo cancellation or any combination of the two configurations. The ZL50234 supports ITU-T G.165 and G.164 tone disable requirements.