XR-2120A

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. The XR-2120A utilizes silicon gate CMOS technology and switched-capacitor circuit techniques to minimize external components and enhance overall performance. The XR-2120A, available in a 24-Pin Package, is designed to operate from dual 5 volt or a single 10 volt power supply. FEATURES 1200 Hz/2400 Hz Transmit and Receive Bandpass Filters...