Select Language
Integrated 10/100/1000 Gigabit Ethernet Transceive
General Description

The Realtek RTL8251CN-VB-GR is a highly integrated Ethernet transceiver that complies with 10Base-T, 100Base-TX, and 1000Base-T IEEE 802.3 standards. It provides all the necessary physical layer functions to transmit and receive Ethernet packets over CAT 5 UTP cable or CAT 3 UTP (10Mbps only) cable.

The RTL8251CN-VB uses state-of-the-art DSP technology and an Analog Front End (AFE) to enable high-speed data transmission and reception over UTP cable. Functions such as Crossover Detection & Auto-Correction, polarity correction, adaptive equalization, cross-talk cancellation, echo cancellation, timing recovery, and error correction are implemented in the RTL8251CN-VB to provide robust transmission and reception capabilities at 10Mbps, 100Mbps, or 1000Mbps.

Data transfer between MAC and PHY is via the Reduced Gigabit Media Independent Interface (RGMII) for 1000Base-T, 10Base-T, and 100Base-TX.


  • 1000Base-T IEEE 802.3ab Compliant
  • 100Base-TX IEEE 802.3u Compliant
  • 10Base-T IEEE 802.3 Compliant
  • IEEE 802.3 Compliant RGMII
  • Supports Auto-Negotiation
  • Supports Parallel Detection
  • Crossover Detection & Auto-Correction
  • Automatic polarity correction
  • Transmit wave-shaping
  • DSP processing
  • Internal hybrids for 1000Base-T
  • Baseline Wander Correction
  • Support Interrupt function
  • Supports half/full duplex operation
  • Transmission rate up to 1Gbps over industry standard CAT.5 UTP cable with BER less than 10-10 in 1000Base-T
  • The design transceiver capability target is up to 120M for CAT.5 cable in 1000Base-T
  • Supports 3.3V or 2.5V signaling for RGMII
  • Supports 25MHz external crystal or OSC
  • Provides 125MHz clock source for MAC
  • Provides 2 network status LEDs
  • Supports Link Down power saving
  • Built-in switching regulator
  • 48-pin QFN
  • 0.11µm process with very low power consumption
Network Interface Adapter, MAU (Media Access Unit), CNR (Communication and Network Riser), ACR (Advanced Communication Riser), Ethernet hub, and Ethernet switch.
In addition, it can be used in any embedded system with an Ethernet MAC that needs a UTP physical connection.


Realtek to Demonstrate Full Range of Connectivity, Multimedia, and Consumer Electronics Solutions at 2018 CES
Realtek to Demonstrate Full Range of Connectivity, Multimedia, and Consumer Electronics Solutions at 2017 CES
Realtek PCIe GBE Family Controller Series Drivers
Realtek PCIe FE Family Controller Series Drivers
HD Audio Codec Driver
Monthly Revenue Update
About Realtek | Products | Press Room | Downloads | Investor Relations | Employment | Contact Us | FAQs | Site Map
Contact the Webmaster about any website related problems.
Best viewed at 800x600 with
IE 6.0 or Netscape 7.02 or Mozilla Firefox 1.0.6 or higher.
©2018 Realtek Semiconductor Corp. All rights reserved.