Basic principles of llc resonant half bridge converter and dcdynamic circuit simulation examples introduction llc resonant half bridge converters are widely used in consumer electronics, like powering the display panel of lcd tv. The resonant llc power topology is valued for its inherently high levels of efficiency credited to high frequency, low loss resonant switching. Design consideration of half bridge llc resonant converter, journal of power electronics, 71. Introduction to resonant converter pantech solutions. Llc resonant converters increase efficiency in dctodc. This guide covers how to run and get familiar with the highvoltage halfbridge llc resonant dcdc. The evm accepts dc input voltage in the range 350v to 400v and delivers a regulated 12v dc output, in the range from zero load to 340w power.
Design and implementation of llc resonant half bridge converter abstract. Design and implementation of llc resonant half bridge. This increase in their industrial application has given rise to more efforts in enhancing the softswitching, smooth waveforms, highpower density, and high efficiency features of the resonant converters. Notice the difference with the halfbridge shown in figure. An introduction to llc resonant halfbridge converter. Resonant llc halfbridge dcdc converter software design guide. Another researcher in suggested an llc series resonant converter based led driver with pfc boost converter which was operated in ccm, and a quasihalf bridge resonant converter that worked under zvs to reduce switching losses. This example circuit uses scripting to determine the minimum magnetics ratio of magnetizingresonant, ln lmlr, to provide the desired gain and output power of an llc resonant converter. Design of a novel apwm halfbridge dcdc resonant converter with load independent softswitching and reduced circulating current. Designing an llc resonant halfbridge power converter article.
Modeling and design of high power halfbridge llc resonant. Applying synchronous rectification in resonant halfbridge. Three advantages are achieved with this resonant converter. Schematic and basic waveforms for hb llc converter operating at resonant frequency. The fan7621s is a pulse frequency modulation controller for highefficiency halfbridge resonant converters. Llc resonant converter is proposed for front end dcdc conversion application. This design is a digitally controlled 300w resonant llc halfbridge dcdc converter with added synchronous rectification. Their selection will impact these converter characteristics. Steadystate models of the high power llc resonant network were researched. Their suitability to high frequency usage and capacity to.
However, the operating principles of a llc resonant half bridge converter are far from apparent and intuitive 1. Pdf design of half bridge llc resonant converter using. It includes explanation of llc resonant converter operation principle, designing the transformer and resonant network, and selecting the components. Proper selection of these two factors is the key point for the llc resonant converter design. For an indepth discussion of llc resonant dcdc converters and their design considerations, along with a design process example, please refer to sem1900 topic 3, designing an llc resonant. The converter consists of a switching bridge halfbridge mosfet, an llc resonant circuit, a fullbridge rectifier and an output filter co.
The analysis showed how this converter can be operated advantageously along wide ranges, both of output voltages and. The concept of switch mode power supply smps is explained below using a dc to dc converter. Unlike the slr converter, the llc converter can keep the output voltage regulated even under light load condition. The irs27951,2 is a self oscillating halfbridge driver ic for resonant halfbridge dcdc converter applications for use up to 600v.
The proposed converter achieved a constant voltage and current, which were required to drive high brightness led lamps. The dcdc llc resonant converter reference design utilizes microchips digital power conversion dspic for unique adaptive control of the halfbridge converter and synchronous rectifier. Keywords soft switching, quality factor q, voltage gain m. Use fundamental approximation and ac simulation in any simulation software like pspice, icap4 etc r. The switching circuit in the reference design uses a halfbridge topology, so the halfbridge voltage swings between 0v and vd 400 vdc nominal. The stepbystep design procedure explained with a design example helps design the llc resonant converter. Microchips 200w dcdc llc resonant converter reference design. It utilizes the magnetizing inductance of the transformer to construct a complex resonant tank with buck boost transfer characteristics in the softswitching region.
The llc converter is a resonant inverter with 3 reactive elements where dc input voltage is turned into a square wave by a switch network arranged as either a half or fullbridge. Converter with synchronous rectification kits hvllc project. An introduction to llc resonant halfbridge converter introduction although in existence for many years, only recently has the llc resonant converter, in particular in its half bridge implementation, gained in the popularity it certainly deserves. Resonant halfbridge converters provide a costeffective and efficient solution for offline power supplies in the range of 200 w to 500 w. Resonant lcc converter for lowprofile applications a. The high power halfbridge llc converter was modeled and analyzed with first harmonic approach so as to obtain the optimal parameters. The frequency can be programmed externally through the rt and ct pins. Recently, dcdc resonant converters have received much research interest as a result of the advancements in their applications. Introduction to resonant converter, theory of resonant converter, mode of operation for half bridge resonant converter, driving pulse for mosfet, product description. The principle schematic of a half bridge llc converter is shown in figure 3.
Design of half bridge llc resonant converter for low voltage dc applications doi. A halfbridge lcc resonant converter was simulated and implemented, assuming steadystate operation under variable frequency control. Drm119, llc resonant acdc switchedmode power supply. Design considerations for a halfbridge llc resonant converter. Half bridge llc resonant converter design using ice1hs01g. This application note presents design considerations of an. This reference design is implemented using a single dspic33ep dspic33fj gs digitalpower dscs from microchip that provides the full digital. This design guides users stepbystep through the complexities of a resonant llc halfbridge converter, melding software and hardware design approaches to. The llc converter is a resonant inverter with 3 reactive elements where dc input voltage is turned into a square wave by a switch network arranged as either a half or full bridge.
Prc topology besides the two part resonant tanks, there are almost 40 possibilities of three part resonant tanks. The most popular member of three part tanks is the llc resonant converter. Llc resonant converter design using mc56f82748, design reference manual, rev. An4151 halfbridge llc resonant converter design using fsfr. The dcdc llc resonant converter reference design utilizes microchips digital power conversion dspic for unique adaptive control of the half bridge converter and synchronous rectifier. This topology is also known as an llc converter, with the name derived from the fact that the resonant tank comprises two inductors and one capacitor. A closedloop control of high power llc resonant converter for dcdc applications, nirma university international conference, pp. The llc resonant circuit reduces switching loss through zerovoltage switching zvs. The circuit topology selection depends on many parameters like output power, input voltage, outputinput voltage ratio, and so on.
Llc resonant half bridge converter employing fsfrseries fps. The proposed fb src features a novel twomode operation. One issue in a fullbridge llc relates to holding the input voltage bus constant enough not to effect the resonant waveforms. Design and experimental evaluation of a singlestage acdc. It feeds the resonant llc tank that filters out harmonics providing a sinusoidal like voltage and current waveform. This paper presents the design of a phaseshifted fullbridge series resonant converter psfb src. An introduction to llc resonant halfbridge converter introduction although in existence for many years, only recently has the llc resonant converter, in particular in its halfbridge implementation, gained in the popularity it certainly deserves. It has a fixed 50% dutycycle and very wide operating frequency range. By delaying the turnon time of switch q2, the circuit achieves primaryside zvs and obtains a soft commutation of the rectifier diodes on the secondary side. Application note evaluation board 600w half bridge llc with 600v. The maximum switching frequency can go up to 500khz. Where the switching bridge gain is 1 for a fullbridge and 0.
Design of a novel apwm halfbridge dcdc resonant converter with. Power electronics resonant switching tutorialspoint. The resonant tank circuit is made up of a capacitor, an inductor, and the magnetizing inductance of the isolating transformer. This application note describes how to design half bridge llc resonant converter using ice1hs01g, which is an 8pin llc controller developed by infineon technologies. A simple design and simulation of full bridge llc resonant. The ucd38llcevm028 evaluation module evm is a digitally controlled halfbridge resonant llc converter based on the ucd38 programmable digital power controller. Design of half bridge llc resonant converter for low. Pdf digital control of a halfbridge llc resonant converter. Ice1hs01g is specially designed for applications of switch mode power supplies used in lcd pdp tv, acdc adapter and audio system. Offering everything necessary to build a reliable and robust resonant converter, the fan7621s simplifies designs and improves productivity, while improving performance. The waveforms below are for a half bridge converter also known as a pushpull.
Highvoltage halfbridge llc resonant dcdc converter with. The resonant tank gain can be derived by analyzing the equivalent resonant circuit shown in figure 2. What are the challenges in full bridge llc resonant converter. And9408 basic principles of llc resonant half bridge. Converter with synchronous rectification kits hvllc. Tidmresllcdcdc resonant llc halfbridge dcdc converter. The converter consists of a switching bridge half bridge mosfet, an llc resonant circuit, a full bridge rectifier and an output filter co. Where the switching bridge gain is 1 for a full bridge and 0. When designing a halfbridge llc, the resonant capacitor can be split. Design considerations for a half bridge llc resonant. Application note an1160 design of resonant halfbridge.