Transceivers support dual-port functionality.

Press Release Summary:

Series DP83849 PHYTER® of application specific transceivers directly interface to MAC devices and microcontrollers through IEEE 802.3u-compliant MII/RMII interfaces. With flex-port switching technology, units also include cable diagnostics with TDR and dynamic link quality monitor to detect faults and check quality. Models DP83849C, DP83849ID, DP83849I, and DP83849IF support JTAG IEEE 1149.1 test standard for ease of manufacturing and also feature Auto-MDIX.

Original Press Release:

National Semiconductor Introduces Industry's First Dual-Port Transceivers with Flex-Port Switching and Advanced Cable Diagnostics

Family Offers Unique Features to Enable a New Class of High-Speed Industrial Connectivity Devices

SANTA CLARA, Calif. - October 24, 2006 - National Semiconductor Corporation (NYSE:NSM), a leading supplier of high-speed interface devices, today introduced four application-specific, dual-port industrial physical layer transceivers with unique flex-port switching technology and advanced cable diagnostics. National's DP83849 PHYTER® family of commercial and industrial transceivers address the expansive, unique needs of embedded design engineers who are developing products that require high-speed industrial connectivity and dual-port functionality for redundancy and system management.

"National Semiconductor understands the requirements of embedded networking applications and is overcoming the challenges with products that feature unique industry innovations, such as flex-port switching capability," said Jeff Bock, global marketing manager for Freescale's consumer and industrial microcontrollers. "National's PHYTER dual family has outstanding reliability and interoperability that enable Freescale to provide a robust, high-performance connected solution on our ColdFire® 68K microcontrollers and PowerQUICC(TM) evaluation boards and reference designs."

National's highly integrated DP83849C, DP83849ID, DP83849I and DP83849IF dual-port transceivers include a powerful cable diagnostic that features time domain reflectometry (TDR) and a dynamic link quality monitor, including signal-to-noise ratio (SNR) estimation. TDR detects faults during installation, saving significant man-hours of de-bug work. Additional innovative cable diagnostics provide real-time continuous dynamic monitoring of the link quality. For example, the SNR estimation allows system designers to implement a fault prediction mechanism to detect changing or deteriorating link conditions and proactively take corrective action, saving lengthy system downtime and costly repairs.

In addition, the DP83849I and DP83849IF feature a unique, patent-pending flex-port switching capability. This feature allows the two ports to be internally connected to provide fully integrated distance extension, fiber-to-copper media conversion and hardware-based failover. Other port mapping options easily can be configured to enable unique port monitoring and network connection topologies.

National guarantees IEEE 802.3u specification compliance by test for all of National's dual transceiver units shipped.

National's DP83849 transceivers will be shown in National's booth #506 in Hall A4 at the Electronica trade show in Munich, Germany from November 14-17.

Technical Features of the DP83849 Dual PHYTER Family of Transceivers
The DP83849 PHYTER family boasts error-free operation over 137 meters of cable, reliably exceeding the Ethernet IEEE 802.3u specification of 100 meters. They interface to twisted pair media or fiber via an external transceiver. In addition, the family fully supports the joint test action group (JTAG) IEEE 1149.1 test standard for ease-of-manufacturing. They interface directly to media access control (MAC) devices through the IEEE 802.3u-compliant MII or RMII interfaces. By supporting both MII and RMII interfaces, the family has flexibility to interface to a wide range of microcontrollers. The family also features Auto-MDIX, transparently allowing the end user to use straight or cross-over cables.

The DP83849C transceiver addresses the quality, reliability and cost requirements of embedded developers networking their devices in commercial temperature applications. In addition to key features such as enhanced cable diagnostics and IEEE 802.3u specification compliance, National's DP83849C incorporates a 25 MHz clock-out that eliminates the need, and hence space and cost, of an additional MAC clock source component. System designers can realize an additional 75-cent cost saving per port by implementing this feature. For more information on the DP83849C or to order samples and an evaluation board, visit

The DP83849ID transceiver is well-suited for harsh factory environments that require fiber media support. National characterized it to operate over the industrial temperature range of -40 degrees C to +85 degrees C and supports dual enhanced cable diagnostics. For more information on the DP83849ID or to order samples and an evaluation board, visit

The DP83849I transceiver features flex-port technology that enables configuring of the two ports to provide fully integrated range extension or repeater mode, media conversion from fiber to copper and hardware-based failover to guarantee uninterrupted network operation and port monitoring. The enhanced cable diagnostics, industrial temperature range and the industry's highest electrostatic discharge (ESD) protection of 4000V make this device well-suited for factory floor and building automation applications. For more information on the DP83849I, or to order samples and an evaluation board, visit

The DP83849IF transceiver includes support for fiber, flex-port switching and enhanced cable diagnostics. It also includes energy-detection circuitry for intelligent power management to increase system reliability. For more information on the DP83849IF or to order samples and an evaluation board, visit

National also provides the PHYTER integrity software utility that provides unmatched access for system support, debug and system design work. Available for download at, this utility gives the user complete access for link, status, device configuration and network status monitoring, and has been developed to support current and future National Semiconductor products.

About National's Interface Products

National Semiconductor, the LVDS technology innovator and market leader, offers a wide range of interconnect solutions that transfer high-speed digital signals using world-class analog technology. These solutions help system designers develop high-performance applications in a variety of markets, including communication and industrial systems. The products feature high reliability, low power and low noise, as well as dramatic systems savings in cable and connector costs. National Semiconductor is the world's largest supplier of high-speed LVDS products, according to Databean's 2005 Analog IC Market Share survey. For more information on National's interface products, visit

Packaging, Pricing and Availability
Available now, all four transceivers are packaged in lead-free 80-pin TQFPs. In 1,000-unit quantities, the DP83849C is priced at $4.50, the DP83849ID is $4.89, the DP83849I is $5.25 and the DP83849IF is $5.82. For more information on National's Ethernet products, visit

About National Semiconductor
National Semiconductor, the industry's premier analog company, creates high-value analog devices and subsystems. National's leading-edge products include power management circuits, display drivers, audio and operational amplifiers, interface products and data conversion solutions. National's key analog markets include wireless handsets, displays and a variety of broad electronics markets, including medical, automotive, industrial, and test and measurement applications. Headquartered in Santa Clara, Calif., National reported sales of $2.16 billion for fiscal 2006, which ended May 28, 2006. Additional company and product information is available at

Gayle Bullock
National Semiconductor Public Relations
3689 Kifer Road, M/S G1-124
Santa Clara, CA 95051
Tel: (408) 721-2033
Cell: (408) 464-2516
Fax: (408) 721-3238

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