DS3253+

The DS3253+ from Analog Devices (Maxim Integrated) is a triple Line Interface Unit (LIU) that performs essential functions for interfacing at the physical layer to DS3, E3, or STS-1 lines. Each LIU features independent receive and transmit paths and includes a built-in jitter attenuator. An on-chip clock adapter generates all necessary line-rate clocks from a single input clock.

This device supports multiple control interface options, including 8-bit parallel, SPI, and hardware mode. It offers receive clock and data recovery capabilities and standards-compliant transmit waveshaping. The jitter attenuators can be placed in either the receive or transmit paths and have provisionable buffer depths of 16, 32, 64, or 128 bits. It also supports B3ZS/HDB3 encoding and decoding, along with local and remote loopbacks.

Operating at a low power of 3.3V with 5V tolerant I/O, the DS3253+ is suitable for industrial temperature ranges from -40°C to +85°C. It is housed in a compact 144-pin, 13mm x 13mm thermally enhanced CSBGA package, making it a drop-in replacement for older DS3151/52/53/54 LIUs. The device also supports IEEE 1149.1 JTAG.

Applications for the DS3253+ include SONET/SDH and PDH multiplexers, digital cross-connects, access concentrators, ATM and Frame Relay equipment, routers, PBXs, DSLAMs, and CSU/DSUs. It requires minimal external components for operation.