Quad Ethernet Transceiver Targets SOHO, Enterprise Applications

SOHO and enterprise designers have a new weapon in their arsenal. The National Semiconductor DP83864 four-port GigPHYTER quad Ethernet physical-layer (PHY) transceiver specifically targets multiport small-office/home-office (SOHO) switches, high-density enterprise switches, and router products. Also, this full-featured transceiver's integrated physical-media-dependent sublayers support 10BaseT, 100BaseTX, and 1000BaseT versions of Ethernet.

The four complete ultra-low-power PHYs are made with National's 0.18-µm CMOS. Each 10/100/1000-Mbit/s port interfaces directly to the unshielded twisted pair via an external transformer. The chip interfaces directly to the media-access-control layer through the IEEE 802.3u standard Media Independent Interface (MII) or the 802.3z Gigabit Media Independent Interface (GMII). And, it supports the reduced-pin-count RGMII and SGMII versions.

The DP83864's unique integrated on-chip microcontroller enables the customization of features like control of output LED pins, Internet-protocol phone detection, and cable diagnostics. Competitive solutions require external logic to handle these functions.

GigPHYTER leverages National's heritage with innovative analog design techniques compared to traditional DSP-centric parts. The chip provides an optimum mix of linear signal conditioning in cooperation with DSP to minimize data bus width while maximizing signal conditioning. This approach produces a smaller chip with a lower power consumption of about 1 W per port.

The DS83864 is available in a 292-pin plastic ball-grid-array (PBGA) package. It uses a 1.8-V supply for the core and analog circuits and 2.5 V for other analog and I/O circuits. Evaluation boards and reference designs are available. The device costs $20 in quantities of 10,000 units.