ZL50235

• Independent multiple channels of echo cancellation; from 16 channels of 64ms to 8 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 IO 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 ZL50235 Voice Echo Canceller implements a cost effective solution for telephony voice-band echo cancellation conforming to ITU-T G.168 requirements. The ZL50235 architecture contains 8 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 16 channels of 64 milliseconds to 8 channels of 128 milliseconds echo cancellation or any combination of the two configurations. The ZL50235 supports ITU-T G.165 and G.164 tone disable requirements.