The input voltage of an Electric Vehicle (EV) Electronic Control Unit (ECU) is the electrical voltage supplied to the ECU from the vehicle's power system. Most EV ECUs are designed to operate with input voltages ranging from approximately 10-15 V, which is the standard output from the vehicle's battery system.  However, the input voltage of an EV ECU varies depending on the specific function of the ECU within the vehicle. Different ECUs operate at different voltage levels based on their function.

The ECU incorporates sophisticated power management systems that regulate various internal voltages required for its operation. This includes generating lower voltages (like 5 V, 12 V, etc.) necessary for different sensors and actuators within the vehicle. For example, a DC-DC converter may be used to adjust the battery's output voltage to meet these varying needs. The input voltage not only powers the ECU itself but also enables it to supply necessary voltages to other vehicle components. These include sensors that monitor vehicle dynamics, battery management systems, and communication interfaces such as the CAN bus, which enables communication between multiple ECUs. 

Common Input Voltages for EV ECUs:

• Low Voltage ECUs (12 V–48 V): EV ECUs that control auxiliary systems such as lighting, infotainment, climate control, and body electronics operate on 12 V to 48 V systems.
• High Voltage ECUs (200 V–800 V): Powertrain-related ECUs such as battery management system (BMS) ECUs, motor control ECUs, and power electronics control ECUs operate on high-voltage battery systems. Depending on the EV's architecture, high-voltage systems typically range from 200 V to 800 V.

Typical Voltage Breakdown: The typical breakdown voltage for low-voltage systems for auxiliary components is 12 V and is similar to conventional vehicles. Hybrid systems have more advanced systems with higher-power auxiliary components. They have a breakdown voltage of around 48 V. Most passenger EVs operate with 200 V-400 V battery packs. In contrast, high-performance or fast-charging EVs use 600 V–800 V systems to boost efficiency and reduce charging times.

Power Source:  The auxiliary battery (12 V) provides power to low-voltage ECUs. The main battery pack (200 V-800 V) provides power to high-voltage ECUs responsible for the EV powertrain and battery management.

Click here to learn more about EV ECUs featured on everything PE