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This paper introduces a new nonlinear voltage-mode controller for a PWM dc-dc buck converter operating in continuous conduction mode. The sliding-mode control technique is used to derive a simplified equivalent control law based on the averaged dc-dc buck converter dynamics. As opposed to the reported design approaches, the proposed control scheme only requires the output voltage in the feedback loop without the need to the capacitor current. Thus, the analogue implementation cost is reduced and the drawback of adding a capacitor current sensor to the power converter is eliminated. The control equation is realized in a simple analogue circuit using few op-amps and resistors, which is suitable for industrial applications. The system modeling and control design procedure along with the derivation of the existence and stability conditions are presented. The control system performance is analyzed using MATLAB and SaberRD simulations. Furthermore, a simple analogue prototype of the simplified nonlinear voltage-mode controlled dc-dc buck converter is developed on a PCB. The simulation and experimental results show that the controller maintains a constant switching frequency, exhibits fast transient response, and provides good tracking performance under large disturbances. [ABSTRACT FROM AUTHOR]

This paper introduces a new type of switched-mode gate driver, which is capable of operating at high frequencies. This topology satisfies requirements of small passive storage components, low-voltage stress, and high design flexibility. Most popular gate-drive circuits require at least two transistors. The proposed circuit has only a single transistor and is suitable for operation at switching frequencies on the order of several megahertz. The output voltage of the gate driver is a quasi-rectangular waveform shaped by a resonant network to produce the desired gate–source voltage waveform. A detailed steady-state operation of the proposed gate driver is discussed. The power-loss analysis and design procedure are presented. Experimental results are given to verify the presented analytical approach. A laboratory prototype of the gate driver is designed, built, and tested at a switching frequency of 20 MHz. [ABSTRACT FROM AUTHOR]

A buck dc–dc converter with ripple reduction has been proposed previously. However, detailed characterisation and performance analysis were not conducted. This study presents steady-state analysis, design, and performance evaluation of the zero-voltage ripple (ZVR) buck dc–dc converter in continuous conduction mode (CCM). The ZVR buck converter is capable of eliminating the output voltage ripple by employing a two-winding auto-transformer. The expressions for steady-state current and voltage waveforms are given. The equations for the design of the converter components are derived. A step-by-step procedure to design the auto-transformer for the ZVR buck converter using the area-product method is introduced. Derivations of expressions for the power losses in passive components, magnetic core, windings, and semiconductor devices are presented. A laboratory prototype of the ZVR buck converter in CCM with input voltage 12 V, output voltage 5 V, output power 10 W, and switching frequency 500 kHz was designed, built, and tested. Simulation results showing the superior performance of the ZVR buck converter over the poly-phase converters are given. Experimental results are provided to validate the theory. It was observed that the ZVR buck converter produces nearly zero ripples at any duty cycle with efficiency in the order of 90%. [ABSTRACT FROM AUTHOR]

Modern energy transmission and signal reproduction techniques rely upon power amplifiers that must operate with high efficiency. An increasingly popular technique for addressing this problem involves replacing the fixed power amplifier supply voltage V D D with a controlled, variable voltage provided by a dynamic power supply. Although pulse-width modulated dc-dc buck converters typically function as fixed-output supplies, this paper provides new theoretical dc analysis for operation wherein the output voltage is controlled and continuously variable over a wide range. A design procedure for the variable-output buck converter is derived. Key device parameters affecting converter speed and efficiency are identified. The dc analysis and design procedure are verified experimentally, with calculated and measured parameters shown to be in good agreement. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]