Thirty years ago, the car was a miracle in mechanical engineering, but by today’s standards, its construction is quite simple: the entry-level car is equipped only with a radio and electronic ignition; The window regulator is manual; the instrument panel is equipped with an electromechanical speedometer and some warning lights; Power is transmitted directly from the battery to the headlights via a switch on the dashboard…… Cars at that time had no anti-lock braking system (ABS) and airbags, nor a central computer, and all parts used analog signals and were independent of each other.
The core concept and design logic of the zone control architecture
Today, vehicles integrate hundreds of features, many of which are required by regulations or demanded by consumers. To achieve these functions, automakers are installing electronic control units (ECUs). Each system (braking, lighting, infotainment, etc.) is equipped with its own ECU, software, and wiring. Over time, a complex network of 100 to 150 ECUs has formed in a single car, and this network continues to become more complex. To break through this complexity, automakers are adopting software-defined vehicle (SDV) architectures. SDV is designed to centralize software control, simplifying the update, management, and expansion of functions. However, even with this shift, the underlying cabling and distributed hardware can still become a bottleneck if automakers do not rethink the physical architecture of the vehicle.
Thus, the Zone Control Architecture was born, a modern location-based design strategy that complements SDV principles and significantly simplifies vehicle systems.
Figure 1. Schematic diagram of the traditional architecture 30 years ago, using centralized power distribution
Zone control architecture is a paradigm shift that organizes vehicle electronics based on location rather than function. Instead of having a dedicated ECU for each subsystem, zone controllers are installed in various areas of the vehicle, such as the front left corner, right rear corner, or cabin. These controllers manage local devices such as lights, switches, and sensors within their respective areas. Instead of each component running its own software, the zone controller acts as a central hub for power distribution and data communication.
These zone controllers are connected to a central computer that houses the core software that defines the vehicle’s behavior. Thus, for central locking, lighting or temperature control, there is no need for a separate ECU, the central computing unit makes the decision and the zone controller takes care of the execution.
This shift replaced hundreds of point-to-point lines with simpler, more manageable area layouts, significantly improving design clarity and system efficiency.
settleregiondeviseThe essentialtruechallenge,Core advantages highlight major progress
Despite the significant advantages of zone control architectures, the implementation process is not without its challenges. First, not all edge modules can completely strip away smart features. Some components, such as advanced lighting systems, still require local processing for performance, safety, or proprietary functionality. These modules offered by Tier 1 suppliers come with built-in software because they have the expertise to program and control the modules.
This presents a core challenge for SDVs with a zonal design, which is to balance centralized control with localized flexibility. In many cases, the automaker handles the central computing software, while the Tier 1 supplier manages the embedded software for the modules manufactured. Achieving a software-only central brain is the goal, but often requires compromises.
Traditional ECUs use traditional communication protocols such as CAN and LIN, which work with standalone modules but become difficult to manage when scaled up in zone control architectures. This is exactly what automotive Ethernet (especially10BASE-T1SWhere does it work?
10BASE-T1S is a low-speed (10 Mbps) multi-branch Ethernet standard designed for automotive applications. It allows multiple nodes, such as headlights, turn signals, and door locks, to share a pair of twisted pairs, reducing the need for expensive point-to-point connections.
Figure 2. 10BASE-T1S multi-branch connection example
This approach simplifies cabling, reduces costs, and leverages Ethernet’s mature ecosystem, including time synchronization and error recovery capabilities, avoiding the overhead of high-speed Ethernet such as 100BASE-T1 or Gigabit Ethernet. For low-bandwidth devices, these high-speed Ethernet are unnecessary.
Overall, zone control architectures offer five advantages for vehicle development, production, and operation:
Reduce cabling complexity and weight: Reducing the use of wires and connectors reduces vehicle weight and manufacturing time.
Reduce material and assembly costs: Simplified wiring means lower manufacturing costs and easier maintenance.
Improve scalability: New features can be added or changed through software without redesigning the hardware layout.
Centralized software control: Streamlining the development process and supporting over-the-air (OTA) updates is a key enabler for SDV.
Smarter function coordination: Take lighting as an example. In conventional vehicles, headlights flashing when unlocked requires the integration of multiple ECUs. In zone design, a central computer sends a single command, which is then executed by the corresponding zone controller, eliminating the need for redundant cabling or separate lighting logic.
From Ethernet to smart switches,onsemi helps transform to a regional control structure
As the world’s leading supplier of automotive semiconductor technology, onsemi believes that zone control architectures represent a paradigm shift in the way vehicles are designed and manufactured, and by providing industry-leading products and solutions, onsemi is helping global automakers transform into zone control architectures. By grouping functions by physical location and leveraging Ethernet-based communication, automakers significantly reduce system complexity, cabling costs, and maintenance difficulty.
For example, a zone controller is not only responsible for data relay but also distributes power to components within its area. This means that they play a key role in system safety and diagnostics, and for this reason, onsemi attaches great importance to the role of smart switches, which have gone far beyond basic circuit protection. These smart devices have the following features:
· Voltage and current monitoring for each channel
· Supports automotive safety standards such as ASIL B, ASIL D, etc
· Fail-safe and fail-safe operation mode ensure continuous function even when a fault is detected
For example, in the event of a fault, ON Semide Smart Switches can reduce power, isolate faults, or enter safe fallback mode instead of completely turning off critical systems like headlights. This insight and control is crucial for higher levels of autonomous driving.
Figure 3. Typical regional power distribution architecture
When combined with the principles of software-defined vehicles, zone design paves the way for faster innovation, wider customization, and smarter diagnostics. With enabling technologies such as 10BASE-T1S, remote control protocol ICs, and intelligent power distribution, onsemi is helping automakers realize this vision, providing scalable, safe, and efficient zonal control solutions to meet the evolving needs of modern mobility.
