Marvell Alaska 88E1121R
Dual-Port Gigabit Ethernet Transceiver with Integrated Passives
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
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 Alaska 88E1121R
• Supports RGMII interface
• Significantly reduces pin count on board design
• Four RGMII timing modes
• Eliminates the need for on-board delay lines
• Integrated MDI interface termination resistors and capacitors
• Reduces board space and BOM cost, improves signal integrity, improves
reliability resulting in overall system cost
• Energy detect and energy detect+ low-power modes
• Reduces power consumption and extends battery life
• Coma mode support
• Flexible power-down functionality
• “Downshift” mode for two-pair cable installations
• Compatible with legacy cables/applications. Preserves the Ethernet link
should the quality deteriorate in four-pair cables
• Automatic MDI/MDIX crossover at all speeds of operation
• Eases installation and reduces costs by working with both straight
and cross-over cables
• Automatic polarity correction
• Compensates for wiring problems
• Line and system loopback modes and packet generator
• Enables testing and debugging in stand-alone mode
• IEEE 802.3u compliant Auto-Negotiation
• Automatically configures to 10, 100, or 1000 Mbps operation
• Software programmable LED modes including LED testing
• Allows for a user-defined LED configuration
• Supports IEEE 1149.1 JTAG
• Simplifies board level testing/debugging
• MDC/MDIO management interface
• Provides flexible management options
• Advanced Marvell Virtual Cable Tester (advanced Marvell VCT™)
• Identifies and isolates cable faults
Fig 2. 88E1121R Functional Block Diagram of Single Port
THE MARVELL ADVANTAGE: Marvell products come with complete reference designs which include board layout designs, software, manufacturing
diagnostic tools, documentation, and other items to assist customers with product evaluation and production. Marvell’s worldwide field application
engineers collaborate closely with end customers to develop and deliver new leading-edge products for quick time-to-market. Marvell utilizes worldleading semiconductor foundry and packaging services to reliably deliver high-volume and low-cost total solutions.
ABOUT MARVELL: Marvell is the leader in storage, communications and consumer silicon solutions. Marvell’s diverse product portfolio includes switching,
transceiver, communications controller, processors, wireless, power management and storage solutions that power the entire communications infrastructure,
including enterprise, metro, home, storage, and digital entertainment solutions. For more information, visit our website at
Marvell Semiconductor, Inc.
5488 Marvell Lane
Santa Clara, CA 95054
Phone 408.222.2500
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