Out in Front: March 14, 1996

Integrated Circuit Systems has announced the ICS1890 Fast Ethernet transceiver, which requires fewer than 10 external passive components and consumes less than 1W. The all-CMOS design integrates adaptive equalization, encoding/ decoding, clock recovery/transmit, and auto-sense and -negotiation circuitry. A media-independent interface allows the IC to connect with standard repeater or media-access controllers.

One key to the low passive parts count is the integration of 10/100-Mbps switching capabilities in the ICS1890. Fast Ethernet designs must support the lower speed during the 100BaseTX auto-sense and -negotiation phase. Many early Fast Ethernet implementations relied on separate 10- and 100-Mbps datapaths within a transceiver chip or chip set. Such cases require external relays or transistor-based switches to route 10- or 100-Mbps traffic to the appropriate datapath. The ICS1890 easily connects to off-the-shelf 100BaseTX magnetic components and implements all physical-layer functions for both 10BaseT and 100BaseTX data rates.

Sampling now, the ICS1890 costs $21.40 (10,000). The 64-pin QFP is also available on an evaluation board.
—by Maury Wright

Integrated Circuit Systems Inc, San Jose, CA. (408) 297-1201.