LXT9785/9785E - Low-Power 8-Port Ethernet Transceiver The LXT9785 and LXT9785E are Cortina's lowest power, highest performance octal 10/100 transceivers. The LXT9785/9785E transceivers simplify multi-port switch design through low power, previous-generation register compatibility, and multiple interfaces. The LXT9785/9785E transceiver complies with all applicable requirements of IEEE 802.3 standards and demonstrates superior Ethernet performance with operation up to 200 meters. LXT9785 and LXT9785E are identical except for the Voice over IP (VoIP) telephony features included in the LXT9785E transceiver. The LXT9785E is an enhanced version of the LXT9785 that detects data terminal equipment (DTE) capable of being powered remotely from the switch over a Category 5 cable. The system can use the information collected by the LXT9785E to apply power over the cable if the link partner requires it, such as an IP telephone. The LXT9785E offers an easy to use solution for OEMs designing VoIP systems that need to be as robust as typical PBX-based telephone systems.
Applications
  • Ethernet switches
  • VoIP enabled Ethernet switches (LXT9785E)
  • Storage area network equipment
  • Harsh environment equipment
  • Features and Benefits
  • Eight independent 10Base-T, 100Base-TX, or 100Base-FX ports
  • DTE discovery enables IP telephones to be powered remotely via a category 5 cable
  • Low power consumption (250 mW/port typical)
  • 2.5V operation
  • Compatible with 2.5V and 3.3V I/O
  • Multiple interfaces: RMII, SMII, SS-SMII
  • Auto-MDI/MDIX
  • Robust baseline wander correction
  • Auto-negotiation, parallel detection
  • MDIO Sectionalization for 1x8 or 2x4 configurations
  • Register compatibility with LXT9781 and LXT9782
  • Configurable via MDIO port or external control pins
  • JTAG boundary scan
  • Integrated termination resistors
  • Superior EMI performance
  • Carrier Class Ethernet Support offers extended temperature (-40°C to +85°C) performance (LXT9785HE)
  • Technical Documents
    Product Briefs
    Cortina Systems® LXT9785 and LXT9785E 8-port 10/100 Tranceivers with Carrier Class Ethernet Support Product Brief
    Application Notes
    LXT9785 and LXT9785E PHY Transceiver Cable Diagnostics Application Note
    100BASE-FX Fiber Optic Transceivers: Connecting a PECL/LVPECL Interface Application Note
    LXT9784-to-LXT9785/LXT9785E Migration Guide Application Note
    LXT9785 Design and Layout Guide Application Note
    IP Telephony and DTE Discovery Using Ethernet PHYs
    LXT9785/9785E 8-port Fast Ethernet 10/100 Mbps Physical Layer Transceiver Cable Diagnostics
    LXT9785/LXT9785E PHY: Restart of Auto-Negotiation During Internal Loopback
    Datasheets
    LXT9785 and LXT9785E Advanced 8-Port 10/100 Mbps PHY Transceivers
    Manuals
    LXD9785 PQFP Demo Board with FPGA for RMII-to-MII Conversion Development Kit Manual
    LXD9785 PQFP Demo Board with FPGA for SMII-to-MII Conversion Development Kit Manual
    LXD9785 PQFP Demo Board with FPGA for SS-SMII (Fiber)-to-MII Conversion Development Kit Manual
    LXD9785 PQFP Demo Board with FPGA for SS-SMII-to-MII Conversion Development Kit Manual
    LXD9785MBC BGA15 Demo Board with FPGA for SS-SMII-to-MII Conversion Evaluation Kit
    Migration from the LXT9781 to the LXT9785/LXT9785E
    FAQs
    LXT9785/9785E Frequently Asked Questions
    Specification Updates
    LXT9785/9785E Advanced 10/100 8-Port Transceivers Specification Update
    IBIS and BSDL Models
    LXT9785/9785E 2.5V IBIS Models
    LXT9785/9785E 3.3V IBIS Models
    LXT9785/9785E BSDL Files
    Application Briefs
    Solutions for IP Telephony Application Brief
    Product Change Notifications
    PCN103459 - 00 Telecom & Networking Products, FYI, BGA Tray Standardization 2006-Sep-02
    PCN106766 - 02 Ethernet Phy, MAC, Framers, T1/E1, Legacy Phy and Framers - Product Marking and Packaging Change, Product Marking 2006-Oct-12
    PCN106238 - 00 LXT9785 Advanced 8-Port 10/100 Mbps PHY Transceiver, LXT971 Single Port 10/100BASE-TX Ethernet Transceiver, and LXT384 Octal LIU Octal PCM Transceiver, Order Code & Product Marking Change 2006-Apr-28
    PCN0107-02.1 Ethernet Phy, MAC, Framers, T1/E1, Legacy Phy and Framers - Product Marking Change 2007-Jan-24
    PCN0207-04.0 LXT9785 Advanced 8-Port 10/100 Mbps PHY Transceiver, LXT971 Single Port 10/100BASE-TX Ethernet Transceiver, and LXT384 Octal LIU Octal PCM Transceiver, Order Code & Product Marking Change 2007-Feb-28
    DCL200711-01 Early Shipments due to IT Shutdown and Conversion 2007-Nov-06
    DCL0108-01.0 Product Code Change 2008-Jan-04
    DCL200802-01.0 Cortina Systems, Inc. Products (Ethernet Phy, MAC, Framers, T1/E1, Transport and Legacy Phy, & EPON), DCL200802-01.0; FYI – Europe & Middle Eastern Region Orders and Payment Transition 2008-Feb-05
    PCN0308-04.0 Cortina Systems, Pack Change, Select QFP's 2008-Mar-25
    PCN0308-01.0 Cortina Systems, Product Marking Change, FYI 2008-Mar-13
    DCL200804-01 Cortina Systems, Inc. Products (Ethernet Phy, MAC, Framers, T1/E1, Transport and Legacy Phy, & EPON), ; FYI – Latin America Regions Order and Payment Transition, DCL200804-01 2008-Apr-14
    PCN400579 Select HQFP 208, LQFP 64/32 Packages, Manufacturing Site Change 2008-May-09
    PCN400614 Cortina Systems 400614_GDLXT9785MBC.D0_Pkg_Conv_FFF_PCN 2008-Jul-07
    PCN400627 Cortina Systems_400627_LXT9785_BGA_Package_Conversion_Site_Change_FFF 2008-Jul-17