Exar’s full suite of SONET/SDH solutions provides customers innovative and market-proven product options.  Options that are easily integrated, standards compliant, provide superior jitter performance, eliminate unnecessary discrete devices, reduce costs and accelerate time-to-market. Think of it, more features yet fewer components.

The XRT83VL38 is a fully integrated Octal (eight channel) long-haul and short-haul line interface unit for T1 (1.544Mbps) 100Ω, E1 (2.048Mbps) 75Ω or 120Ω, J1 110Ω or BITS Timing applications.

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. It also provides programmable transmit pulse generators for each channel that can be used for output pulse shaping allowing performance improvement over a wide variety of conditions (The arbitrary pulse generators are available in both T1 and E1 modes).

The XRT83VL38 provides both a parallel/serial Hostmicroprocessor interface as well as a Hardwaremode for programming and control.

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 pathswith 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. It supports internal impedance matching for 75Ω, 100Ω, 110Ω and 120Ω for both transmitter and receiver. In the absence of the power supply, the transmit outputs and receive inputs are tri-stated allowing for redundancy applications The chip includes an integrated programmable clock multiplier that can synthesize T1 or E1 master.