Title :
Non-zero error method for improving output voltage regulation of low-resolution digital controllers for SMPS
Author :
Zhenyu Zhao;Aleksandar Prodic
Author_Institution :
ECE Department, University of Toronto, 10 King?s College Road, ON, M5S 3G4, Canada
Abstract :
A simple method for achieving tight output voltage regulation in digitally controlled low-power dc-dc switch-mode power supplies with low-resolution digital pulse-width modulators (DPWM) is introduced. By utilizing a non-zero scheme for coding the output voltage error, an inherent quasi sigma-delta modulation effect improving effective DPWM resolution is obtained. The effectiveness of the method is experimentally verified on a 400 kHz, 5 V to 1.8 V, 5 W digitally-controlled buck converter. Using a 6-bit DPWM and the new coding scheme only, undesirable low-frequency limit-cycle oscillations (LCO), existing in conventional designs, are eliminated and tight output voltage regulation obtained.
Keywords :
"Voltage control","Error correction","Digital control","Switched-mode power supply","Pulsed power supplies","Space vector pulse width modulation","Digital modulation","Pulse modulation","Delta-sigma modulation","Buck converters"
Conference_Titel :
Applied Power Electronics Conference and Exposition, 2008. APEC 2008. Twenty-Third Annual IEEE
Print_ISBN :
978-1-4244-1873-2
DOI :
10.1109/APEC.2008.4522860
