Out in Front: May 9, 1996
A pair of universal line interface ICs for long- and short-haul links meets both the 1.544-Mbps T1 and 2.048-Mbps E1 specifications. Level One's LXT360 and LXT361 are designed for distances that have cable attenuation as high as 43 dB, or 6000 ft (2 km) of 22 AWG (0.6-mm) cable; they interface to twisted-pair lines via standard pulse transformers and resistors. The two ICs differ only in their processor interfaces; the LXT360 offers hardware and serial µP control, and the LXT361 features a Motorola/Intel-compatible parallel port.
Because jitter attenuation is critical in most applications, the LXT360 and LXT361 implement a digital, no-crystal jitter-reduction technique. As a result, the devices require no external crystal for this function. The ICs also include features such as a suite of loop-backs, quasirandom, signal-source self-test generation and detection, driver-failure monitor, loss-of-signal alarms, and short-circuit current-limit protection. The 28-lead ICs, which come in PLCC and DIP packages, cost $15.95 (1000).
—by Bill Schweber
Level One Communications Inc, Sacramento, CA. (916) 855-5000, fax: (916) 854-1101.