45W dual output type-C buck converter design and charging application for automotive applications

This study covers the design, simulation, prototyping, and testing stages of a 45 W USB Type-C Power Delivery (PD) converter for automotive applications. The system is implemented with a buck-boost topology based on the MPQ4230 converter and the MPQ5031 PD controller, capable of providing 5V, 9V, and 12V PD profiles from an input range of 9–16 V. The design process takes into account detailed circuit analyses, printed circuit board (PCB) layout studies, and compliance with automotive standards such as AEC-Q100. The study thoroughly addresses input filtering structures to withstand automotive electrical transients, optimization of the power conversion stage, and the implementation of the USB PD protocol. Simulation results and laboratory test findings demonstrate that the output voltage regulation remains within ±1% accuracy for all PD profiles, efficiency exceeds 93% (reaching 94.5% at 9 V / 3 A output), and load transient response occurs in under 500 μs. Thermal performance tests show that, under full load conditions, MOSFET temperature remains below 30°C and inductor temperature below 32°C. The originality of this design lies in its focus on automotive-grade components and compliance with stringent EMI/EMC requirements. Furthermore, challenges encountered during the integration of high-power USB-C charging capabilities in vehicles—such as voltage dips at engine start and noise induced by the alternator—are also addressed. Dynamic load sharing and support for multiple USB-C ports demonstrate the system's flexibility for in-vehicle infotainment systems and mobile device charging applications. Finally, the detailed analysis of thermal management and EMI reduction techniques in PCB layout provides a valuable contribution for engineers working on high power-density designs. Keywords: AEC, Automotive Electronics Council, DC-DC Choppers, Four Switch Buck-Boost Topology, ECU