XRT75R12D

www.DataSheet4U.com PRELIMINARY XRT75R12D REV. P1.0.1 TWELVE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH SONET DESYNCHRONIZER OCTOBER 2003 GENERAL DESCRIPTION The XRT75R12D is a twelve channel fully integrated Line Interface Unit (LIU) featuring EXAR’s R3 Technology (Reconfigurable, Relayless Redundancy) for E3/DS3/STS-1 applications. The LIU incorporates 12 independent Receivers, Transmitters and Jitter Attenuators in a single 420 Lead TBGA package. Each channel of the XRT75R12D can be independently configured to operate in E3 (34.368 MHz), DS3 (44.736 MHz) or STS-1 (51.84 MHz). Each transmitter can be turned off and tri-stated for redundancy support or for conserving power. The XRT75R12D’s differential receiver provides high noise interference margin and is able to receive data over 1000 feet of cable or with up to 12 dB of cable attenuation. The XRT75R12D incorporates an advanced crystalless jitter attenuator per channel that can be selected either in the transmit or receive path. The jitter attenuator performance meets the ETSI TBR-24 and FIGURE 1. BLOCK DIAGRAM OF THE XRT 75R12D Bellcore GR-499 specifications. Also, the jitter attenuators can be used for clock smoothing in SONET STS-1 to DS-3 de-mapping. The XRT75R12D provides a Parallel Microprocessor Interface for programming and control. The XRT75R12D supports analog, remote and digital loop-backs. The device also has a built-in Pseudo Random Binary Sequence (PRBS) generator and detector with the ability to ins...