Pulse-Frequency-Modulated Digital Control of Power Supply Without Analog-to-Digital Converter Using Positive-Sloped Ramp Wave Injection

• Published in: IEEE transactions on industrial informatics Vol. 9; no. 2; pp. 739 - 748
• Main Authors: Hwu, K. I., Chuang, C. F., Yau, Y. T.
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01-05-2013; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Analog to digital conversion; Capacitors; Converters; Counter-based; Distortion; Field programmable gate arrays; Logic gates; one-comparator; output voltage ripple; positive-sloped ramp wave injection; pulse-frequency-modulated; Ramps; Ripples; Strategy; Switches; Switching frequency; Voltage; Voltage control
• ISSN: 1551-3203; 1941-0050
• DOI: 10.1109/TII.2012.2223476

In this paper, a counter-based pulse-frequency-modulated (PFM) control strategy according to the output voltage ripple using a one-comparator scheme without any analog-to-digital converter (ADC) used is presented, which is realized based on the field programmable gate array (FPGA) and applied to DC-DC converters. However, too small or distorted output ripple limits its performance. Consequently, a positive-sloped ramp wave injection method is used to overcome this problem and enhances its application capability significantly. First of all, the details of the positive-sloped ramp wave injection method are illustrated, and second some experimental results are provided to verify the effectiveness of the proposed control strategy.