Buck converter

About: Buck converter is a research topic. Over the lifetime, 22530 publications have been published within this topic receiving 313580 citations. The topic is also known as: Buck Chopper & step-down converter.

Active cancellation of capacitor ESR and ESL effects for improving converter transient and steady-state response

Abstract: An active cancellator that can reduce the capacitor equivalent series resistance (ESR) and equivalent series inductance (ESL) effects and provide capacitor current information is presented. The concept is based on connecting a linear voltage source in series with the capacitor to counteract the voltage drops caused by the ESR and ESL. Due to a reduction in the effective ESR and ESL, the damped resonant frequency of the “modified” capacitor is increased. The performance of the cancellator has been evaluated on an aluminum electrolytic capacitor. The effective values of the ESR and ESL are reduced by 1850 and 6.5 times, respectively, with the cancellator. The “modified” capacitor has been applied to a practical buck regulator. The capacitor current information provided by the cancellator is used to give an extra phase boost in the feedback loop of the regulator. Experimental results show that the proposed technique can help reduce the duration of ESL spike and magnitude of the ESR step appeared in the load transient, and steady-state output voltage ripple.

Regulation of a lightweight high efficiency capacitor diode voltage multiplier DC-DC converter

Abstract: A method for the regulation of a capacitor diode voltage multiplier dc-dc converter has been developed which has only minor penalties in weight and efficiency. An auxiliary inductor is used, which only handles a fraction of the total power, to control the output voltage through a pulse width modulation method in a buck boost circuit.

Constant-voltage and constant-current buck converter and control circuit

Abstract: A control circuit is provided for a buck converter that includes at least an inductor coupled to an output of the buck converter. The control circuit includes a power switch configured for coupling to a line voltage and configured for charging the inductor, an input line voltage sampling circuit, and a constant-voltage (CV) and constant-current (CC) control module coupled to the power switch. During a charging period of the inductor, the CV and CC control module is configured to control the power switch to provide a constant output current by maintaining a constant peak inductor current, even when the input line voltage changes. During a discharging period of the inductor, the CV and CC control module is configured to monitor the sensed output voltage to control the power switch to provide a constant output voltage.

Analysis and design of an active-clamp buck converter with coupled inductors

Abstract: This paper presents analysis and design of an active-clamp buck converter with coupled inductors. The active switch in the converter can sustain a long enough duty cycle while it operates with a high step-down voltage ratio, reducing current stress significantly. In the converter, the active-clamp circuit is used to eliminate voltage spike induced from the leakage inductor of the coupled inductors. Moreover, since both main and auxiliary switches can be turned on with zero voltage switching, switching loss can be reduced and conversion efficiency therefore can be improved significantly. A 120 W prototype of the proposed buck converter was built and experimental results have shown that efficiency can reach as high as 95% (power stage only) and surge can be suppressed effectively. It is relatively feasible for applications to hybrid electric vehicle on-board chargers.

Switch type buck regulator circuit

Abstract: The invention relates to a switch type buck regulator circuit, comprising a voltage input end, a voltage output end, a chip and peripheral circuit elements. The chip comprises a switch element, a trigger, a comparator and a reference voltage source, wherein the trigger outputs a control signal for controlling the switch element to be switched on or off, a reference voltage of the reference voltage source is input into the positive end of the comparator, and the signal output end of the comparator and the output end of an oscillator are respectively connected with the input ends of the trigger. The switch type buck regulator circuit is characterized in that the chip also internally comprises a current-limiting resistor (Rsc), a divider resistor (R1), a divider resistor (R2) and a charging and discharging capacitor (CT) of the oscillator which are all integrated in the chip so that four peripheral elements are correspondingly reduced in a peripheral circuit, the circuit cost is decreased, the chip has stronger market competitiveness, and the labor cost for making a PCB (Printing Circuit Board) can be decreased by using less peripheral elements.