Marvell Alaska 88E1121R
Dual-Port Gigabit Ethernet Transceiver with Integrated Passives
PRODUCT OVERVIEW
The Marvell
®
Alaska
®
88E1121R dual-port Gigabit Ethernet (GbE) transceiver is a physical layer (PHY) device containing
two independent GbE transceivers on a single monolithic IC. The transceivers implement the Ethernet PHY portion of the
1000BASE-T, 100BASE-TX, and 10BASE-T standards and are compliant with IEEE 802.3u Auto-Negotiation. It is manufactured
using standard digital CMOS process and contains all the active circuitry required to implement the physical layer functions
to transmit and receive data on standard CAT 5 unshielded twisted pair.
The 88E1121R device supports the Reduced Gigabit Media Independent Interface (RGMII) for direct connection to a Media
Access Controller (MAC)/switch port. The device also integrates Media Dependent Interface (MDI) termination resistors and
capacitors into the PHY. The integration of the passives simplifies board layout and significantly reduces board cost and space
by eliminating up to 24 external components. The Marvell calibrated resistor scheme will achieve and exceed the accuracy
requirements of the IEEE 802.3 return loss specifications.
The 88E1121R can operate with just two voltages, 1.2V for the core and 1.8V/2.5V/3.3V for I/O. It consumes only 700 mW
per port and features energy detect and energy detect+
™
low-power modes. It supports data terminal equipment (DTE)
power function for Power over Ethernet (PoE) applications. The device also incorporates the advanced Marvell Virtual Cable
Tester
®
(advanced Marvell VCT
™
) feature for remote identification of potential cable malfunctions, thus reducing equipment
returns and service calls. Housed in a 100-pin TQFP package and measuring only 16mm x 16mm on each side, the 88E1121R
is the smallest dual-port Gigabit Ethernet PHY on the market.
Example Application: IP Phone
Example Application: DVR
APPLICATIONS
The 88E1121R is ideal for IP phones and other applications requiring low power and a small footprint. In an IP phone, where
board space is constrained, the integrated resistor scheme on the 88E1121R allows for shorter MDI traces and thus improved
IEEE template performance. Other benefits of the integrated passives on the 88E1121R include: higher reliability with fewer
components on the board, reduced board assembly time and cost, better ICT yield from the elimination of board soldering
issues, and improved signal integrity and potential reduction in EMI with terminations located at the very end of the signal path.
Additional applications include DVRs, game consoles, NAS appliances, and workstation or desktop PCs. The 88E1121R is a
drop-in replacement for the 88E1121 PHY and can be used to upgrade existing designs without the need to re-spin the board.
Fig 1. 88E1121R Application Diagram
MARVELL [ MARVELL TECHNOLOGY GROUP LTD. ]
