GENERAL DESCRIPTION
In long-haul applications the XRT83L30 accepts signals that have passed through cables from 0 feet to over 6000 feet in length and have been attenuated by 0 to 45dB at 772kHz in T1 mode or 0 to 43dB at 1024kHz in E1 mode. In T1 applications, the XRT83L30 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 B8ZS and HDB3 encoding and decoding functions are included and can be disabled as required. On-chip crystal-less jitter attenuator with a 32 or 64 bit FIFO can be placed either in the receive or the transmit path with loop bandwidths of less than 3Hz. The XRT83L30 provides a variety of loop-back and diagnostic features as well as transmit driver short circuit detection and receive loss of signal monitoring. It supports internal impedance matching for 75Ω, 100Ω, 110Ω and 120Ω for both transmitter and receiver.
Exar Corporation
