Out in Front: March 28, 1996

Using the Micro Linear ML6692, you can design single-speed (100-Mbps) and dual-speed (10/100-Mbps) Fast Ethernet adapters, repeaters, and switches using just one device per interface port. Dual-speed ports are useful, because they allow interconnection at 10 times the speed of a conventional Ethernet connection and maintain compatibility with lower speed networks. This IC partitions the lower speed transceiver into the Ethernet controller—a more cost-effective implementation. A 12-port repeater design, for example, would use 12 of these ICs instead of 24, plus a single controller.

The BiCMOS device incorporates a multiplexer that combines its own 100-Mbps output with the Ethernet controller’s 10-Mbps output. The ML6692 also includes an autonegotiation circuit, which queries the system to determine whether to use the higher or lower transfer speed, whether the system requires half- or full-duplex transmission, and which cable type is in use. In addition, the ML6692 supports other 100BaseTX physical-layer specifications of the IEEE 802.3 standard, including baseline-wander correction, adaptive equalization, various encode/decode formats, and 125-MHz clock recovery and generation.

Typical power consumption is 250 mA from a 5V supply. In 52-lead PLCCs and 64-lead TQFPs, the device costs $27.35 and $27.95 (1000), respectively.
—by Bill Schweber

Micro Linear Corp, San Jose, CA, (408) 433-5200.