A digital PWM controlled KY step-up converter based on frequency domain ΣΔ ADC

Xia Du, Chi-Seng Lam, Sai-Weng Sin, Man-Kay Law, Franco Maloberti, Man-Chung Wong, Seng-Pan U, Rui Paulo Martins

Abstract: This paper introduces a digital PWM control of the KY step-up converter based on frequency domain sigma-delta (ΣΔ) analog-to-digital converter (ADC), in which we deduce the mathematical modeling of the KY step-up converter and the frequency-domain digitization technique based on the first-order non-feedback sigma-delta frequency discriminators (NF-SDFD). Then, the digital control of the KY converter with voltage control oscillator (VCO), NF-SDFD, cascaded integrator comb (CIC) decimator, PID compensator and digital pulse width modulation (DPWM) generator has been successfully built in MATLAB Simulink for verification. This modeling work is useful in the design of a low power digital controlled KY step-up converter with low output voltage ripple and fast transient response.