XR-2120 Datasheet | Exar

DESCRIPTION FUNCTIONAL BLOCK DIAGRAM The X R-2120 is a self-contained bandpass fi Iter set designed for realization of Bell 212A patible 1200 bits/sec PSK modems. The XR-2120 utilizes CMOS technology and switched capacitor circuit techniques to minimize external ponents to a single crystal or frequency source. Contained in the device are two plete bandpass filters centered around the Bell standard 1200 Hz and 2400 Hz send and receive frequencies. These filters also provide promise line equalization. Additional features included are digitally programmable transmit and receive gains as well as input anti-aliasing and plete output smoothing filters. Separate VSS pins for transmit, receive, and digital sections are provided to minimize crosstalk. The XR-2120 features guaranteed filter group delay specifications, within ±1001l S of nominal. The XR-2120C is a relaxed version of the X R-2120 with group delay specified within ±15QIl S. The...