Transceivers Switch All T1/E1/J1 Standards

Requiring no external component changes, the DS21455 and DS21458 take their place as the industry's first four-port transceivers that can switch between all T1, E1 and J1 standards. The devices provide all line-interface and framer functions necessary to connect four T1, E1, or J1 lines without the aid of relays or switched external components. With a single clock supporting T1, E1, or J1 operating modes, all ports are independently configurable and can be interleaved on the same 16.384 MHz backplane. Additional features include software-selectable receive and transmit termination, two HDLC controllers per port, programmable bit-error-rate testing, and optional crystal-less jitter attenuation. The DS21455 is pin and software compatible with the company’s DS21Q55, while the DS21458 is software compatible with the DS21Q55. Prices for the DS21455 and DS21458 start at $39.99 and $36.99 each/1,000, respectively. DALLAS SEMICONDUCTOR, Dallas, TX. (800) 998-8800.