Line Interface Units

Two new products, the XRT82L34 (four-channel LIU), and the XRT82L38 (eight-channel LIU), have been added to the company's DS1/E1 product family. The devices are compliant with applicable industry leading DS1/E1 standards. Applications for the multi-channel devices include digital cross connects, channel banks, T1/E1 multiplexers, high-speed data transmission line cards, as well as public switching systems and PBX interfaces.

The two DS1/E1 LIUs include clock and data recovery, line drivers and jitter attenuators on a single chip. Both the four and eight-channel product meets G.772 monitoring standard and allows redundancy to be built into the system without additional components. It also supports 1149.1 compliant JTAG in-circuit test capability, and allows improved manufacturing yield during system assembly.

Each channel consists of a receiver with equalizer for reliable clock and data recovery, and a transmitter, which accepts either single or dual-rail inputs for signal transmission to the line using a low impedance line driver. Each device also includes a crystal-less jitter attenuator which, depending on system requirements, can be selected to receive or transmit through the Host or Hardware Mode control.

The parts meet or exceed specifications in ITU G.703, G.775, G.736 and G.823; TR-TSY-000449; ANSI T1.403 and ETSI 300-166. All parts are low power CMOS devices and require only a single 3.3 Volt supply. All digital inputs are 5 Volt tolerant.

Exar Corp., 48720 Kato Rd., Fremont, CA 94538. Tel: 510-668-7000; Fax: 510-668-7021.