TDK LIUs integrate programmable jitter attenuator

TDK Semiconductor Corp. has announced the release of its family of single-chip, multichannel DS3/E3/STS-1 LIUs that integrate a programmable jitter attenuator (JAT) to enable the devices to meet the E3/T3 jitter standards, including TBR 24 and G.499.

Manufactured using a 0.185m digital CMOS process, the 78P2342JAT dual-port, 78P2343JAT triple-port, and 78P2344JAT quad-port LIUs are suitable for T3/E3 applications such as WAN/ATM transmission, DSLAMs, digital cross-connects, add/drop MUX, test equipment, and DLC equipment.

According to Andy Mills, SVP and GM of the broadband products group, "By using regular vanilla CMOS, rather than a bipolar or BiCMOS process, we are able to provide higher levels of integration and ultimately lower system costs for our customers."

The company claims that the pure digital CMOS-based 0.185m design of the LIUs allows better integration of enhanced digital monitoring features and provides improved functionality with integrated JAT, a serial microprocessor interface port, programmable redundancy features and programmable JAT FIFO depths.

The integrated JAT function can be configured via the serial management port for either Tx/Rx paths. Each channel can be configured independently by writing to the JAT Control Register.

The devices also provide an adaptive digital clock recovery and transmitter pulse shaping functions, along with an integrated AGC that corrects up to 12dB of cable and 6dB of flat loss. This allows the LIUs to drive distances up to 1,200 feet over a variety of operating conditions.

The 78P2342/43/44JAT are shipped in 100-pin TQFP casings, and are also available without the JAT function.