New Renesas Automotive HD Link Solution For Automotive Cameras

By Tiera Oliver

Associate Editor

Embedded Computing Design

July 19, 2021


New Renesas Automotive HD Link Solution For Automotive Cameras

Renesas announced its new Automotive HD Link (AHL) technology designed to enable automotive manufacturers to deliver high-definition video over cables and connectors currently supporting standard-definition video.

The new RAA279971 AHL encoder and RAA279972 decoder use a modulated analog signal to transmit the video. According to the company, the encoder and decoder enable transmission rates up to 10x less than required to transmit HD signals digitally. The lower transmission rate means that traditional twisted pair cables and standard connectors can be used, as can existing analog video cables and connectors.

AHL is robust against noise and has a bi-directional control channel that operates independent of the video data and can initialize, program, and monitor the camera module. A key AHL performance feature is the ability to control the camera simultaneously over the same pair of wires (UTP) during video transmission. A safety benefit of AHL is its performance in comparison to a digital link. Per the company, in a rear view camera application, a digital link will degrade due to a failure in the cable harness or connector assembly, as weak signals can cause macroblocks to appear, hiding large portions of the viewing area. Using the same cable under the same conditions for comparison, the AHL link will present a slight change in video color or contrast, but all pixels will appear on the screen, and the image will identify an object or person behind the vehicle.

Additional Features of AHL:

  • Supports resolutions from VGA up to 720p/60 or 1080p/30 to implement non-standard vertical resolutions (not just the TV video standard 16:9 resolutions)
  • MIPI-CSI2, BT656, & DVP inputs and outputs provide interface to support old and new image sensors
  • Requires only 27MHz crystal clock, with internal PLLs able to generate the necessary clock frequencies for higher resolutions

The AHL can be paired with other Renesas products, such as the R-Car Automotive SoCs, RH850 MCUs, automotive PMICs, and analog components to implement safety features in vehicles.

The new RAA279971 AHL encoder and RAA279972 decoder are available today. Renesas also offers the RTKA279971DA2000BU AHL Encoder and the RTKA279972DA1000BU AHL Decoder evaluation boards.

For more information, visit:

Tiera Oliver, Associate Editor for Embedded Computing Design, is responsible for web content edits, product news, and constructing stories. She also assists with newsletter updates as well as contributing and editing content for ECD podcasts and the ECD YouTube channel. Before working at ECD, Tiera graduated from Northern Arizona University where she received her B.S. in journalism and political science and worked as a news reporter for the university’s student led newspaper, The Lumberjack.

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