Out in Front: August 15, 1996

A trio of carefully targeted products from Vitesse Semiconductor is meeting the need for high-speed data-link components, especially in system trunks. The company is aiming the 16-to-1 multiplexer/demultiplexer chip sets for use between 16 622-Mbps, relatively low-speed signals and one 10-GHz, high-speed bit stream. OC-192 specifications for synchronous digital hierarchy-64 require this rate. Current designs use a more costly and complex combination of 4-to-1 or 2-to-1 circuits to achieve the functions that these devices provide.

Vitesse fabricated the VSC8071 16-to-1 multiplexer, which integrates a phase-frequency detector, and the companion VSC8072 1-to-16 demultiplexer in GaAs, and they use standard -2 and -5.2V power supplies. Both devices have 50(ohm) output-drive capability and impedance-matched outputs. They come in high-speed modules and cost $2500.

For 622-Mbps synchronous-optical-network (SONET)/asynchronous-transfer-mode links, the Vitesse VSC8111 transceiver combines serialization and deserialization for 8-bit bytes with a clock multiplier on a single GaAs IC. The transceiver meets Bellcore, CCITT (Consultative Committee on International Telephone and Telegraph), and ANSI specifications for jitter performance and includes a loss-of-signal indicator. You supply an external reference clock at 19.44, 38.88, 51.84, or 77.76 MHz, which the transceiver uses to generate clocks for 155.52- or 622.08-MHz operation via an internal PLL. The 3.3V device consumes 1.2W, about one-half the power of comparable devices, comes in a 100-lead PQFP, and costs $52 (1000).

—by Bill Schweber

Vitesse Semiconductor Corp, Camarillo, CA. (800) 848-3773, e-mail judyc@vitsemi.com