Journal ArticleDOI
An AC-DC LED Driver with a Two Parallel Inverted Buck Topology for Reducing the Light Flicker in Lighting Applications to Low-Risk Levels
TLDR
Considering the power factor and the flicker standards, a design procedure to achieve a high power factor, while minimizing the storage capacitance and the LED current ripple, is presented.Abstract:
This paper presents an ac-dc LED driver that consists of two-parallel inverted buck converters. To buffer the twice-line-frequency energy, one inverted buck converter (also known as a floating buck converter) conveys energy to a storage capacitor, simultaneously performing the power factor correction. The other inverted buck converter regulates the LED current to maintain a constant brightness in the LEDs for reducing the light flicker to low-risk levels. The proposed architecture reduces the voltage stress and the size of the storage capacitor, enabling the use of a film capacitor instead of an electrolytic capacitor. Considering the power factor and the flicker standards, a design procedure to achieve a high power factor, while minimizing the storage capacitance and the LED current ripple, is presented. A prototype of the proposed LED driver has been implemented with an on-chip controller IC fabricated in a 0.35-μm CMOS process and its functionality and performance have been verified experimentally. It demonstrates a power factor of 0.94 and a peak power efficiency of 85.4% with an LED current ripple of 6.5%, while delivering 15 W to the LEDs.read more
Citations
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Journal ArticleDOI
A Review on Flicker-Free AC–DC LED Drivers for Single-Phase and Three-Phase AC Power Grids
TL;DR: This paper reviews the current state-of-the-art strategies to drive LEDs from ac power grids with special emphasis into removing the most limiting component from the point of view of the lifetime, which is the electrolytic capacitor, while achieving a flicker-free performance of the light output of the LED driver.
Journal ArticleDOI
Single-Stage LED Driver Achieves Electrolytic Capacitor-Less and Flicker-Free Operation With Unidirectional Current Compensator
TL;DR: In this paper, a buck converter was used to buffer the imbalance energy between input and output in a half-line cycle of an AC-connected light emitting diode (LED) driver.
Journal ArticleDOI
LED Driver Based on Input Current Shaper Without Electrolytic Capacitor
Guilherme Gindri Pereira,Marco A. Dalla Costa,J. Marcos Alonso,Maicol Flores de Melo,Carlos Henrique Barriquello +4 more
TL;DR: This paper presents a high-power-factor light-emitting diode (LED) driver implemented by using an input current shaper technique and the use of a flyback converter operating as a loss-free resistor provides reduced power processing, increasing the converter's overall efficiency.
Journal ArticleDOI
A Highly Accurate Current LED Lamp Driver With Removal of Low-Frequency Flicker Using Average Current Control Method
TL;DR: In this paper, an average current control method for a light-emitting diode (LED) lamp driver that achieves a highly accurate current and removes low-frequency light flicker was presented.
Journal ArticleDOI
Interferences in AC–DC LED Drivers Exposed to Voltage Disturbances in the Frequency Range 2–150 kHz
TL;DR: In this paper, the impact of supraharmonics (SHs) on light intensity from LED lamps has been analyzed, and the results reveal that the profile of the SH voltage could cause deviations in the modulation depth and the average light intensity.
References
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Proceedings ArticleDOI
Analysis and Optimization of Switched-Capacitor DC-DC Converters
TL;DR: In this article, the performance of a switched-capacitor (SC) DC-DC converter's steady-state performance through evaluation of its output impedance has been investigated, and a simple formulation has been developed that permits optimization of the capacitor sizes to meet a constraint such as a total capacitance or total energy storage limit, and also permits optimizing switch sizes subject to constraints on total switch conductances or total switch volt-ampere (V-A) products.
Journal ArticleDOI
Means of Eliminating Electrolytic Capacitor in AC/DC Power Supplies for LED Lightings
TL;DR: In this paper, two methods of reducing the storage capacitance in the ac/dc power supplies for light emitting diode (LED) lighting were proposed to achieve a long power suppliespsila lifetime.
Journal ArticleDOI
A flicker-free electrolytic capacitor-less ac-dc LED driver
TL;DR: In this paper, a flick-free electrolytic capacitor-less single-phase ac-dc driver for LED lighting is proposed, which consists of an electrolytic capacitive-less PFC converter and a bidirectional converter, which serves to absorb the ac component of the pulsating current of the PFC converters.
Journal ArticleDOI
A Method of Reducing the Peak-to-Average Ratio of LED Current for Electrolytic Capacitor-Less AC–DC Drivers
TL;DR: In this paper, a flyback-based electrolytic capacitor-less light-emitting diode (LED) driver is proposed, which converts the commercial ac voltage to a pulsating current with twice the line frequency driving high-brightness LEDs.
Journal ArticleDOI
The StrongARM Latch [A Circuit for All Seasons]
TL;DR: The StrongARM latch topology finds wide usage as a sense amplifier, a comparator, or simply a robust latch with high sensitivity as mentioned in this paper, and it consumes zero static power, produces rail-to-rail outputs, and its input-referred offset arises from primarily one differential pair.