The MTD981A is a highly integrated analog interface IC for twisted pair Ethernet applications. It provides the active circuitry to interface IEEE 802.3 media independent interface (MII) compliant controllers to 10BASE-T or 100BASE-TX media. It also provides an ECL-type interface for use with 100BASE-FX fiber networks. The MTD981A supports full duplex operation at 10 and 100 Mbps. Its operating condition can be set by using Auto-Negotiation, parallel detection, or manual control. The MTD981A is ideal as a media interface for 10BASE-T/100BASE-TX network interface cards, motherboards, 10/100 repeaters, switching hubs, and external PHYs.