Silicon carbide (SiC) MOSFETs are employed in this design, contributing to high efficiency and fast switching speeds, ideal for high-voltage applications like EV charging systems.
This reference design by Microchip Technology, demonstrates a bidirectional operation system capable of handling both input and output voltage in the range of 700–900 VDC, making it ideal for onboard chargers (OBC) in Electric Vehicles (EVs). The system features hot plug functionality at the output, specifically designed for easy battery connection and disconnection, enhancing the overall convenience for electric vehicle owners. Additionally, the design incorporates a galvanically isolated Controller Area Network (CAN) interface, ensuring robust communication while maintaining electrical isolation between different parts of the system. The system is forced-air cooled and built using AEC-Q100-qualified components, ensuring high reliability and durability under automotive conditions. For optimized performance, the reference design leverages non-linear and adaptive control algorithms, which adjust dynamically to changing operational conditions.
These algorithms are powered by dsPIC Digital Signal Controllers (DSCs), which are critical for managing the control of the power electronics and ensuring efficient operation. This design is part of a modular and configurable hardware platform that uses Plug-in-Modules (PIMs) to support flexible software and different modes of operation. It includes a comprehensive set of components such as an 8-bit microcontroller (MCU), gate drivers, a buck regulator, a Switch Mode Power Supply (SMPS) controller, and a push-pull Pulse Width Modulation (PWM) controller. The CAN FD transceiver and Low Dropout Regulator (LDO) also play a crucial role in ensuring stable communication and power regulation. The design incorporates key components such as the dsPIC33CK512MP608, a 100 MHz single-core DSC for motor control, the PIC16F1764 MCU, the MSC750SMA170 SiC MOSFET, and the MIC2176 synchronous buck controller, among others.
This hardware and software combination delivers exceptional performance and flexibility in EV charging systems. The input voltage ranges from 700 to 900 VDC, with a maximum input current of 17 ARMS, and it supports up to 900 VDC output voltage and 17 ADC output current, achieving a peak power output of 11 kW and an impressive efficiency of 98.5%. Operating at a 100 kHz switching frequency, the system ensures efficient power conversion. Safety features include short-circuit protection, over-temperature protection (up to 100°C), and 4 kV galvanic isolation, guaranteeing safe automotive operation. The system also offers battery hot-plug capability and is designed to function reliably within a temperature range of 0 to 50°C, with a storage range from -40 to 85°C.
Mircrochip Technology Inc. has tested this reference design. It comes with a bill of materials (BOM), schematics, assembly drawing, printed circuit board (PCB) layout, and more. The company’s website has additional data about the reference design. To read more about this reference design, click here.
