AHL Technology Monitors the Camera Function and Enables HD Video Transmission Over Low-Cost Cables and Connectors

13 July 2021 - 0 Comments

Renesas RAA279971 AHL Encoder and RAA279972 Decoder

Renesas Electronics Corporation has introduced new Automotive HD Link (AHL) technology that enables automotive manufacturers to deliver high-definition video over low-cost cables and connectors that currently support standard-definition video. The new RAA279971 AHL encoder and RAA279972 decoder use a modulated analog signal to transmit the video, enabling transmission rates 10 times less than required to transmit HD signals digitally. 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. It can be paired with other products, such as the R-Car Automotive SoCs, RH850 MCUs, automotive PMICs, and analog components to cost-effectively implement numerous safety features in virtually any vehicle.

A key AHL performance and cost reducing feature is the ability to control the camera simultaneously over the same pair of wires (UTP) during video transmission. Another safety benefit of AHL is its performance in comparison to a digital link. 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 precisely identify an object or person behind the vehicle.

Key Features

Supports resolutions from VGA up to 720p/60 or 1080p/30 for flexibility to implement non-standard vertical resolutions (not just the TV video standard 16:9 resolutions)
MIPI-CSI2, BT656, & DVP inputs and outputs provide flexible 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