Title :
Comparison of state-of-the-art digital control and analogue control for high bandwidth point of load converters
Author :
Jakobsen, Lars T. ; Schneider, Henrik ; Andersen, Michael A E
Author_Institution :
Tech. Univ. of Denmark, Copenhagen
Abstract :
The purpose of this paper is to present a comparison of state-of-the-art digital and analogue control for a buck converter with synchronous rectification. The digital control scheme is based on a digital self-oscillating modulator that allows the sampling frequency to be higher than the switching frequency of the converter. Voltage mode control is used in both the analogue and digital control schemes. The experimental results show that it is possible to design a digitally controlled buck converter that has the same performance as can be achieved using commercially available analogue control ICs. The performance of the analogue system can however be increased by using a separate operational amplifier as error amplifier. Thus analogue control is still the best option if high control bandwidth and fast transient response to load steps are important design parameters.
Keywords :
digital control; operational amplifiers; switching convertors; transient response; analogue control; buck converter digital control; digital self-oscillating modulator; error amplifier; load converters; operational amplifier; sampling frequency; switching frequency; synchronous rectification; transient response; voltage mode control; Analog-digital conversion; Bandwidth; Buck converters; Digital control; Digital modulation; Digital-to-frequency converters; Frequency conversion; Operational amplifiers; Sampling methods; Switching frequency;
Conference_Titel :
Applied Power Electronics Conference and Exposition, 2008. APEC 2008. Twenty-Third Annual IEEE
Conference_Location :
Austin, TX
Print_ISBN :
978-1-4244-1873-2
Electronic_ISBN :
1048-2334
DOI :
10.1109/APEC.2008.4522913