Ethernet Chip Dissipates Little Power In Driving Its Three PHYs, Three MACs And Other Circuits

Operating from a single 2.5V supply, the KS8993 Ethernet IC dissipates only 300 mA in powering its three 10/100 physical layer transceivers, three Media Access Control (MAC) units, layer 2 switch, buffer memory, and complementary circuitry. Power consumption climbs to 750 mW when the physical transmit drivers are included. Designed for use in VoIP and small office router and switch applications, this highly-integrated chip can be configured as a standalone three-port device or as two ports plus a router interface to meet a variety of needs, such as connecting DSL to an IP phone and PC lines. For VoIP applications, the IC supports VLAN and priority queuing and both unshielded twisted pair and fiber cables. And, with wire-speed switching, it can service incoming voice packets as they are received. In the two-port mode, access to the third MAC is provided using a reverse or forward Media Independent Interface (MII) so that an external MAC can be directly connected to the chip. The KS8993 switch supports 10BaseT, 100BaseTX and 100BaseFX transmissions conforming to IEEE 802.3 protocols. Other features of the switch include on-chip SRAM for built-in frame buffering, hardware-based 10/100, full or half-duplex flow control and automatic negotiation, and unmanaged operation through strapping at system reset time. The chip also has an integrated address look-up engine that supports 1,000 absolute MAC addresses, automatic address learning, and more. The 128-pin PQFP is sampling now and costs $15 each/1,000.