Courtesy: Renesas
The recent tightening of CO2 emission regulations has accelerated the electrification of automobiles at an unprecedented pace. With the global shift from hybrid vehicles to electric vehicles (EVs), automakers are demanding more efficient, safe, and reliable systems. System integration, known as “X-in-1”, becomes the focus of attention. This innovative concept integrates functions traditionally controlled by separate MCUs, such as inverters, onboard chargers (OBC), DC/DC converters, and battery management systems (BMS), into a single microcontroller (MCU), achieving simultaneous miniaturisation, cost reduction, and efficiency improvement. As electric vehicles evolve, demand grows for X-in-1 configurations that consolidate multiple applications onto a single MCU.
At the core of this X-in-1 approach is Renesas’ RH850/U2B MCUs. This next generation of MCUs delivers the advanced control, safety, and security required by EVs on a single chip. It features a high-performance CPU with up to six cores, operating at up to 400MHz, enabling both real-time control and parallel processing. It also offers comprehensive analogue and timer functions for inverter and power converter applications, enabling efficient control of the entire electrification system on a single chip. Furthermore, the RH850/U2B MCUs offer a wide memory lineup, allowing flexible implementation of the optimal X-in-1 system tailored to specific requirements.
The RH850/U2B MCU demonstrates overwhelming superiority in inverter control, maximising the driving performance of EVs. With dedicated hardware optimised for inverter control, including a resolver-to-digital converter (RDC), an analogue-to-digital converter (ADC), and timers for three-phase motors, the RH850/U2B MCU enables high-speed, high-precision control at the hardware level that software alone cannot achieve. The integrated RDC eliminates the need for external angle detection ICs, contributing to reduced component count and simplified board design. Furthermore, the embedded Renesas proprietary Enhanced Motor Control Unit (EMU) executes complex control calculations in the hardware, significantly reducing CPU load while achieving high-speed, high-precision motor control (EMU is only included in the RH850/U2B6).
The next-generation power devices using silicon carbide (SiC) and gallium nitride (GaN) are increasingly being adopted in OBCs and DC/DC converters. These devices enable high efficiency and fast switching, directly contributing to shorter charging times and improved energy efficiency. On the other hand, the RH850/U2B MCU incorporates a multifunctional timer (generic timer module (GTM)*2 and high-resolution PWM) that is capable of generating high-speed, high-resolution waveforms (minimum resolution of 156.25ps). This facilitates control that leverages the high-speed switching characteristics of SiC and GaN. It also incorporates a 12-bit fast comparator for high-frequency switching control and protection operations.
In addition to speed and energy efficiency, the RH850/U2B MCU also delivers outstanding performance in battery management systems, the heart of EVs. Monitoring and controlling the voltage and temperature of hundreds of cells demands high processing power. The RH850/U2B MCU features a multi-core CPU, allowing surplus resources to be allocated to BMS processing. This enables system miniaturisation and cost reduction without requiring additional MCUs.
As EVs proliferate, the importance of safety and security becomes critical. Compliant with ISO 26262 ASIL D, the RH850/U2B MCU ensures functional safety at the hardware level. It also incorporates security features compliant with EVITA Full, enabling the construction of highly secure systems even in X-in-1 configurations.
The evolution of EVs is moving towards faster, safer, and more efficient use of automobiles. Achieving this requires meeting new demands that conventional MCUs cannot fully address. The RH850/U2B MCU enables users to meet the needs of EVs with high-speed, high-precision inverter control via dedicated hardware; highly efficient switching control in OBCs and DC/DC converters using high-resolution, high-speed timers; multi-core utilisation in battery management systems; and comprehensive safety and security support.
