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XR·2120AADVANCE INFORMATION
212A/V.22 Modem Filter
GENERAL DESCRIPTION
The XR-2120A is a filter system for performing the complete filter function for Bell 212A or CCITI V.22 type modems. The XR-2120A supplies both transmit and receive filtering functions for the standard 1200 Hz and 2400 Hz 212A1V.22 carrier frequencies. Also supplied are mode switching, internal clock generators, input anti-aliasing filters, output reconstruction filters, and digitally controlled transmit and receive gains. Additional features included are CCITI notch filters, additional pin selectable equalization for worst case phone lines and complete analog loopback function.