Practical Limitations of Digitization Methods in Buck Converter Control

This paper reviews digitization methods applied to digital control of a voltage-mode DC-DC buck converter, emphasizing practical limitations due to sampling frequency and quantization effects. The performance of digitization techniques (Tustin, Zero-Order Hold, Matched Pole-Zero and Least Squares) is analyzed through MATLAB/Simulink simulations using realistic parameters derived from the Microchip Buck Converter PICtail™ Plus hardware platform (9 [V] input, 3.3 [V] output, 150 [kHz] switching frequency). Additionally, frequency response-based control, specifically a lead compensation, is employed to enhance the system’s transient response and stability margins. The results provide practical insights for selecting suitable digitization methods and compensation strategies, identifying critical trade-offs at reduced sampling rates, and guiding future digital control implementations in power electronics.