# Single-Switch Non-Isolated Resonant DC-DC Converter for Single-Input Dual-Output Applications  
[PERSON]  
1 Centro Cientifico-Tecnologico de Huelva (CCTH), University of Huelva, 21007 Huelva, Spain; [EMAIL_ADDRESS] (C.D.-M.); [EMAIL_ADDRESS] (S.P.L. ); [EMAIL_ADDRESS] (J.L.A.) 2 Department of Electronic Engineering, Computer Systems and Automation, University of Huelva, 21007 Huelva, Spain 2  
2 Department of Electrical and Thermal Engineering, Design and Projects, University of Huelva, 21007 Huelva, Spain 2  
2 Department of Electrical Engineering, Computer Systems and Automation, University of Huelva, 21007 Huelva, Spain 2  
magnitude of the DC voltage obtained at the output and/or reverse its polarity. Their function is similar to the one performed by a transformer in an AC-AC conversion. A classification of the main switched DC-DC converters can be carried out according to the switching technique used: hard switching (PWM converters) and soft switching (resonant converters), with the resonant converters being the ones that have currently contributed the most to the reduction in size and weight. Converters based on soft-switching techniques use resonant \(L\)-\(C\) elements that cause the sinusoidal variation in voltage and current waveforms in order to reduce switching losses. This feature of the resonant DC-DC conversion techniques is used to shape the current and voltage waveforms of the switches to achieve either zero-voltage turn-on or zero-current turn-off. In fact, they were developed as an alternative to simple rectangular switching, and the power devices switch at high frequency, allowing the converter to maintain an acceptable efficiency (for light loads and full loads) by minimizing the significant switching losses associated with hard switching. In these converters, the size and weight are reduced (mainly magnetic and filtering components), and the power density is increased, with low stress on the switching devices. In addition, the soft-switching technique uses Variable Frequency (VF) for the regulation, with constant on-time or constant off-time. The \(L\)-\(C\) resonant elements generate an oscillating waveform that allows power devices' transitions to occur at zero voltage (zero-voltage switching, ZVS) or at zero current (zero-current switching, ZCS), eliminating or reducing switching losses in the converter and allowing higher-frequency operation, thus reducing the size of the magnetic and filtering components. Both resonant techniques (ZVS and ZCS) are widely used in many applications. Recent publications on ZVS and ZCS soft-switching converters can be found in [1; 2; 3]. Resonant converters can be classified from different points of view and topics: type of converter where they are applied (DC-DC, AC-DC, DC-AC, or AC-AC), applications, efficiency, operating frequency, conversion ratio, number of inputs and outputs, isolated and non-isolated versions, range of voltages, currents and powers [4; 5; 6; 7; 8; 9; 10]. However, the most extended classification is the one that considers the number of resonant circuits used and operation modes. In this sense, the converters are classified as: Resonant Power Converters (RPCs), Resonant Transition Converters (RTCs), Multi-Resonant Converters (MRCs) and Quasi-Resonant Converters (QRCs). RPCs are based on resonant tank stages with several reactive components [11], while RTCs consist of auxiliary switches as well as circuits with capacitors and inductors to produce the resonant action [12]. MRCs [13] and QRCs [14] also use resonant elements (\(L\) and \(C\)) to perform the resonant action, but with the following differences: In MRCs, the resonant action is performed on the two elements of the switching cell (the main switch and the freewheel diode); therefore, ZVS or ZCS conditions can be obtained over both devices. In QRCs, the resonant action is only performed on the main switch. Generally, for any PWM converter, ZCS-QRC and ZVS-QRC configurations can be derived by adding a high-frequency \(L\)-\(C\) tank circuit to the main switching device.