A Class Φ2 Resonant Buck Converter with Ripple Injection Burst Control Method

This paper presents the design and implementation of a DC 120-170V input and DC 48V output class Φ2 resonant buck converter with ripple injection burst control method. For the converter operated at switching frequency of 13.56 MHz, low loss magnetic material is used as resonant inductors instead of air core inductors. By eliminating radiated leakage magnetic flux, small size and high power density can be achieved. Furthermore, this paper proposes a novel ripple injection burst control method to control the class Φ2 resonant buck converter. This method can avoid the effect of output capacitance. As a result of experiment, efficiency of 88.4% is shown at DC 140V input and 144W output, and very good output voltage regulation and dynamic response can be achieved.