A 22 nm CMOS Voltage-Mode PWM Controller for a DC-DC Buck Converter Used in a 32 -Bit RISC-V Microcontroller for IoT Applications

This paper presents the design of a voltage-mode PWM (Pulse Width Modulation) controller, implemented in 22 nm CMOS, for a DC-DC buck switched converter. The presented controller is part of a PMIC (Power Management Integrated Circuit) responsible for powering a SoC (System on Chip), which is a 32-bit microcontroller based on the RISC-V microarchitecture. This microcontroller will be equipped with a RF (radio frequency) interface, designed specifically for IoT (Internet of Things) applications, and the DC-DC buck converter under voltage-mode PWM control is responsible for powering the system under high-load conditions. The results show that the presented controller achieved peak efficiency of 96.4 % at a load current of 20 mA with a minimum output ripple of 6.64 mV. The contributions of this work lie in the advancement of PWM converter technology for modern microcontroller applications, demonstrating the potential of 22 nm CMOS processes to improve power efficiency and performance.