Issue link: https://iconnect007.uberflip.com/i/1541670
56 SMT007 MAGAZINE I DECEMBER 2025 essential for scaling EV adoption because users expect long life, minimal maintenance, and high uptime, even much more so than in legacy ICE (internal combustion engine) vehicles. The Vehicle Control Unit: A Mastermind of Modular Control The VCU is responsible for high-level decisions across the entire EV powertrain. Much like the human brain coordinating bodily functions, the VCU collects data from sensors, communicates with subordinate controllers like the MCU and bat- tery management system (BMS), and makes real- time decisions about torque delivery, braking behavior, thermal management, and energy recuperation. VCUs are tasked with interpreting increasingly complex driving inputs to balance performance, efficiency, and safety in milliseconds. For example, torque vectoring, where power is variably distributed across wheels, relies on the VCU's ability to coordinate motor commands in response to real-time road conditions and driver inputs1. Moreover, VCUs support over-the-air (OTA) software updates and cybersecu- rity protocols. As such, these units have evolved into secure processing hubs with redundant logic paths, error-check- ing mechanisms, and robust electromag- netic compatibility (EMC) safeguards. Functional safety requirements under ISO 26262 stipulate that the VCU must meet stringent Automotive Safety Integ- rity Levels (ASILs), typically targeting ASIL C or D for propulsion-related func- tionality². While the VCU governs the system holistically, the MCU focuses on precise manipulation of the electric traction motor. The MCU's role is to con- vert torque commands into optimized current waveforms that drive the motor. It accomplishes this via pulse width modulation (PWM), field-ori- ented control (FOC), and high-speed switching of insulated gate bipolar transistors (IGBTs) or silicon carbide (SiC) MOSFETs⁴. MCUs must meet exceptionally high-perfor- mance benchmarks while surviving harsh electrical and thermal environments. Switching frequencies Example of a VCU schematic.³ ▼ An MCU assembly.⁷ ▼