GENERAL DESCRIPTION
The XRT83VL38 is a fully integrated Octal (eight channel) long-haul and short-haul line interface unit for T1 (1.544Mbps) 100, E1 (2.048Mbps) 75 or 120 or J1 110applications. In long-haul applications the XRT83VL38 accepts signals that have been attenuated from 0 to 36dB at 772kHz in T1 mode (equivalent of 0 to 6000 feet of cable loss) or 0 to 43dB at 1024kHz in E1 mode. In T1 applications, the XRT83VL38 can generate five transmit pulse shapes to meet the short-haul Digital Cross-Connect (DSX-1) template requirements as well as for Channel Service Units (CSU) Line Build Out (LBO) filters of 0dB, -7.5dB -15dB and -22.5dB as required by FCC rules. Both the B8ZS and HDB3 encoding and decoding functions are selectable as well as AMI. Two on-chip crystal-less jitter attenuators with a 32 or 64 bit FIFO can be placed in the receive and the transmit paths with loop bandwidths of less than 3Hz. The XRT83VL38 provides a variety of loop-back and diagnostic features as well as transmit driver short circuit detection and receive loss of signal monitoring.
Exar Corporation
