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Voltage regulator

About: Voltage regulator is a research topic. Over the lifetime, 33536 publications have been published within this topic receiving 350859 citations.


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Patent
30 Dec 2004
TL;DR: In this article, a bias circuit that generates gate bias voltages by resistance dividers creates a problem in that the values of the resistances constituting the bias circuit must be finely adjusted, and accordingly extra trimming tasks are required.
Abstract: A module including a bias circuit that generates gate bias voltages by resistance dividers creates a problem in that the values of the resistances constituting the bias circuit must be finely adjusted, and accordingly extra trimming tasks are required. The present invention provides current generators that generate currents varying with desired characteristics responsive to a control voltage, independent of variations in transistor threshold voltages, connects output resistors to parallel transistors in respective stages to form current mirror circuits, and supplies currents from the current generators thereto to drive them, instead of supplying dividing voltages.

111 citations

Journal ArticleDOI
TL;DR: In this article, three design criteria for preventing oscillations are derived and interpreted for buck, boost and buck-boost converters, which are summarized in tabular form for the basic buck and boost converters.
Abstract: Addition of an input filter to a current-programmed converter can cause the controller to oscillate. Two instability mechanisms can typically occur: (1) the current programmed controller effective current feedback loop may become unstable, or (2) the controller effective input voltage feedforward loop, which becomes a positive feedback loop when an input filter is added, may oscillate. Three design criteria for preventing oscillations are derived and interpreted. When all three criteria are well satisfied, then the output voltage regulation loop gain is unchanged. Hence, input filters of current programmed converters can be designed in essentially the same manner as for duty-ratio programmed converters. Results are summarized in tabular form for the basic buck, boost, and buck-boost converters. Experimental measurements for a buck converter with different input filters support the theoretical predictions. >

110 citations

Journal ArticleDOI
TL;DR: The key aspect of this regulator is the dynamic bandwidth boosting that takes place in the regulator by sensing the excess current that is bypassed in the limter (during periods of excess energy) and increasing its bias current and hence bandwidth, accordingly.
Abstract: This paper describes a voltage regulator system for ultra-low-power RFID tags (also called passive tags) in a 0.15 mum analog CMOS technology. These tags derive their power supply from the incoming RF energy through rectification instead of from a battery. The regulator is functional with just 110 nA current. Owing to the huge variation of the rectified voltage (by as much as tens of volts), voltage limiters and clamps are employed at various points along the regulation path. A limiter at the rectifier output clamps the rectifier voltage to a narrower range of 1.4 V. A fine-regulator, then, regulates the supply voltage close to a bandgap reference value of 1.25 V. The key aspect of this regulator is the dynamic bandwidth boosting that takes place in the regulator by sensing the excess current that is bypassed in the limter (during periods of excess energy) and increasing its bias current and hence bandwidth, accordingly. A higher bandwidth is necessary for quick recovery from line transients due to the burst nature of RF transmission, with a larger energy burst requiring a higher bandwidth to settle quickly without large line transients. The challenge of compensating such a regulator across various load currents and RF energy levels is described in this paper

110 citations

Journal ArticleDOI
TL;DR: In this article, the authors show that the voltage-source converters of low voltage direct current (LVDC) transmission systems can be tailored as speed-sensorless drives of the wind-turbine induction generators, while meeting the objective of optimal wind-power acquisition.
Abstract: Optimal wind-power acquisition requires automatic tracking of the optimum wind-turbine speed for the prevailing wind velocity. As the wind velocity keeps changing with time so the wind-turbine must keep adjusting its speed. In a wind-farm, the wind velocities depend on the locations of the wind-turbines, each of which has its optimal turbine speed at any given time. With an eye to costs, the wind-farm of this paper is conceived as operating with cheap induction generators driven by variable-speed wind-turbines, without the expense of speed governors. This paper shows that the voltage-source converters of low voltage direct current (LVDC) transmission systems (which are now commercially available) can be tailored as speed-sensorless drives of the wind-turbine induction generators, while meeting the objective of optimal wind-power acquisition. The LVDC system aggregates the power of many wind-turbine induction-generator units into a DC grid. Then a DC voltage regulator inverts the collected power into a three-phase AC electric utility grid.

110 citations

Journal ArticleDOI
TL;DR: In this article, the relationship between the control bandwidth and the load transient response in voltage regulator modules (VRMs), which are designed with multiphase interleaving synchronous buck converters, is investigated.
Abstract: This paper investigates the relationship between the control bandwidth and the load transient response in voltage regulator modules (VRMs), which are designed with multiphase interleaving synchronous buck converters. Both voltage- and current-mode controls are discussed. A critical bandwidth value is discovered, beyond which pushing the bandwidth can no longer reduce the output voltage spike during the load transient response. Also, the critical bandwidths are different according to different kinds of output capacitors. The critical bandwidth concept highlights the trend of high-frequency VRM design that uses ceramic capacitors to achieve smaller size and faster load transient response. Simulation and experimental results prove the theoretical analysis.

110 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202382
2022212
2021320
2020699
2019947
2018973