Long-reach SerDes physical layer specification advancing ADAS, ADS, IVI and other automotive applications

Quick Facts

Key Highlights
  • Targeted for advanced driver assistance systems (ADAS), autonomous driving systems (ADS), in-vehicle infotainment (IVI) and other surround-sensor applications
  • Simplifies integration of lidar, radar and cameras for limited and full vehicle autonomy
  • Improves connectivity for high-resolution safety and infotainment displays
  • Supports functional safety and security
  • Also well-suited for Internet of Things (IoT), industrial and other applications
Fundamental Features
  • Asymmetric data link layer with point-to-point topology
  • 15-meter reach
  • 5 speed gears (2, 4, 8, 12 and 16 Gbps) with roadmap to 48 Gbps and beyond
  • Ultra-low packet error rate (PER) of 10-19 for unprecedented performance over vehicle lifetime
  • High-speed data, control data and optional power share the same physical wiring
  • Reduces complexity, cost, wiring and weight
  • With adaptation layers, provides native support for DSI-2, and VESA’s DP and eDP protocols (with MIPI CSI-2 under development), without a separate software stack
  • Generic data link layer supports approved third-party protocols
  • Ultra-high immunity to EMC effects by virtue of a unique PHY-layer retransmission system
Use Cases



Human machine interfaces (HMI)

In-vehicle infotainment (IVI)


Icon of an AutomobileIcon of a cloud with the letters IoT inside.


MIPI A-PHY℠ v1.0 is a long-reach serializer-deserializer (SerDes) physical layer interface for automotive applications, including ADAS, ADS and other surround-sensor applications, including cameras and in-vehicle infotainment (IVI) displays.

The specification has been developed as an asymmetric data link in a point-to-point topology, with high-speed unidirectional data, embedded bidirectional control data and optional power delivery, all over a single cable. The specification reduces wiring, cost and weight, as high-speed data, control data and optional power share the same physical wiring and will allow designers to optimize systems for the performance, cost and complexity required by their use cases, providing scalability and flexibility to meet a broad range of speed and design needs. For integration with existing network backbones, A-PHY complements Ethernet, CAN, FlexRay and other interfaces.

MIPI A-PHY serves as the foundation of what will be an end-to-end system designed to simplify the integration of cameras, sensors and displays, while also incorporating functional safety and security. Higher-layer MIPI protocols, such as Camera Serial Interface (MIPI CSI-2®) and Display Serial Interface (MIPI DSI-2℠), are already used to connect sensors and displays to domain ECUs and other onboard computers in many vehicles. They currently are transported over MIPI C-PHY℠ or D-PHY℠ shorter-reach physical layers and use "bridge" solutions to connect to proprietary long-reach PHYs. With the use of adaptation layers, these higher-layer protocols will run natively over A-PHY, eliminating the need for these proprietary bridges.

It is anticipated that the first vehicles using A-PHY components will be in production in 2024.

In addition to automotive uses, the specification will be well-suited for applications such as IoT and industrial.

MIPI A-PHY was developed by the MIPI PHY Working Group and is available to MIPI Alliance members. It was also adopted as an IEEE standard in June 2021 and is available as IEEE 2977-2021.

Future enhancements

The next version of A-PHY, v1.1, has already been completed and is now undergoing final member review. This version of the specification will double the maximum downlink data rate in Gear 5 from 16 Gbps to 32 Gbps by supporting dual downlinks over Star Quad (STQ) cables. It will also double the uplink speed from 100 Mbps to 200 Mbps. In addition, A-PHY v1.1 will expand PAM4 encoding to lower gears (G1 and G2), reducing the operating bandwidth of these gears to allow OEMs, Tier 1s and suppliers to implement A-PHY using lower-cost legacy cables and connectors. Upon completion of the MIPI Alliance adoption process, A-PHY v1.1 will also be brought forward for adoption as an IEEE standard.

For information about becoming a member, see Join MIPI.