Analog Devices Inc.

The DS21354/DS21554 single-chip transceivers(SCTs) contain all the necessary functions to connect toE1 lines. The devices are upward-compatible versionsof the DS2153 and DS2154 SCTs. The on-boardclock/data recovery circuitry coverts the AMI/HDB3 E1waveforms to an NRZ serial stream. Both devicesautomatically adjust to E1 22AWG (0.6mm) twistedpaircables from 0 to over 2km in length. They cangenerate the necessary G.703 waveshapes for both 75Ωcoax and 120Ω twisted cables. The on-board jitterattenuator (selectable to either 32 bits or 128 bits) canbe placed in either the transmit or receive data paths.The framer locates the frame and multiframeboundaries and monitors the data stream for alarms. It isalso used for extracting and inserting signaling data, Si,and Sa-bit information. The on-board HDLC controllercan be used for Sa-bit links or DS0s. The devicescontain a set of internal registers that the user canaccess to control the operation of the units. Quickaccess through the parallel control port allows a singlecontroller to handle many E1 lines. The devices fullymeet all the latest E1 specifications, including ITU-TG.703, G.704, G.706, G.823, G.732, and I.431, ETS300 011, 300 233, and 300 166, as well as CTR12 andCTR4.