scholarly journals Light-Load Efficiency Improvement for Ultrahigh Step-Down Converter Based on Skip Mode

Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 355
Author(s):  
Yeu-Torng Yau ◽  
Chao-Wei Wang ◽  
Kuo-Ing Hwu
Keyword(s):  
Integrated Circuit ◽  
Common Ground ◽  
Switching Frequency ◽  
Efficiency Improvement ◽  
Pulse Width Modulated ◽  
Light Load ◽  
Mode 2 ◽  
Skip Mode ◽  
Step Down ◽  
The Cost

In this paper, two light-load efficiency improvement methods are presented and applied to the ultrahigh step-down converter. The two methods are both based on skip mode control. Skip Mode 1 only needs one half-bridge driver integrated circuit (IC) to drive three switches, so it has the advantages of easy signal control and lower cost, whereas Skip Mode 2 requires one half-bridge driver integrated circuit IC, one common ground driver IC, and three independent timing pulse-width-modulated (PWM) signals to control three switches, so the cost is higher and the control signals are more complicated, but Skip Mode 2 can obtain slightly higher light-load efficiency than Skip Mode 1. Although the switching frequency used in these methods are reduced, the transferred energy is unchanged, but the output voltage ripple is influenced to some extent.

A highly efficient GHz switching GaN-based synchronous buck converter module

2020 ◽  
Vol 12 (10) ◽  
pp. 945-953
Author(s):  
Andreas Wentzel ◽  
Oliver Hilt ◽  
Joachim Würfl ◽  
Wolfgang Heinrich
Keyword(s):  
Integrated Circuit ◽  
Buck Converter ◽  
Switching Frequency ◽  
Pulse Width Modulated ◽  
Power Added Efficiency ◽  
Highly Efficient ◽  
Low Pass ◽  
Power Amplifier Efficiency ◽  
Conversion Efficiencies ◽  
First Time

AbstractThe paper presents a highly efficient GaN-based synchronous buck converter suitable for switching in the lower GHz range. The module includes a very compact 2-stage GaN half-bridge converter MMIC (monolithic microwave integrated circuit) for low parasitic inductances between switches and drivers and a hybrid output network with core-less inductors to avoid ferrite losses. At 1 GHz switching frequency the buck converter achieves with pulse-width modulated (PWM) input signals power loop conversion efficiencies up to 78% for 40 V operation and output voltages up to 33 V. For 100 MHz the power loop efficiencies peak at 87.5% for 14.5 W conversion to 25 V. By changing the output network to a 2nd order low-pass with 700 MHz cut-off frequency the module has been characterized for the use as a supply modulator in very broadband envelope tracking systems with modulation bandwidths of up to 500 MHz. For 1 GHz switching frequency the power-added efficiency peaks at 74% for a 90% duty-cycle PWM input signal. The novelty of this work is that for the first time a buck converter design proves highest flexibility supporting different applications from very compact DC converters to microwave power amplifier efficiency enhancement techniques as well as efficient high frequency switching up to 1 GHz.

scholarly journals 2 kW Dual-Output Isolated DC/DC Converter Based on Current Doubler and Step-Down Chopper

2020 ◽  
Vol 11 (4) ◽  
pp. 78
Author(s):  
Yoshinori Matsushita ◽  
Toshihiko Noguchi ◽  
Noritaka Taguchi ◽  
Makoto Ishii
Keyword(s):  
Integrated Circuit ◽  
High Frequency ◽  
Switching Frequency ◽  
Loss Analysis ◽  
Response Characteristics ◽  
Auxiliary Power ◽  
Disturbance Response ◽  
Step Down ◽  
Secondary Side ◽  
A Current

In the context of the auxiliary power for motor-driven vehicles having two systems, we propose a new topology for a dual-output isolated DC/DC converter, which offers advantages in terms of efficiency and size. The proposed circuit consists of an H-bridge inverter, a transformer, and an integrated circuit of a current doubler and step-down chopper. Considering the high power and high frequency, our objective was to evaluate and identify the issues of an actual device with a power output of 2 kW and switching frequency of 400 kHz. The circuit feasibility was examined through measurements of the prototype, and both the voltage target response and load disturbance response characteristics were confirmed to operate as designed. The maximum and minimum efficiencies of this circuit were 81.3 and 61.5%, respectively, demonstrating that the load loss of the step-down chopper had a significant impact on the efficiency. The loss analysis revealed that the loss at the integrated circuit on the secondary side accounted for more than 50% of the total loss. Moreover, issues such as the behavior at power-on, efficiency, and size were identified and evaluated, thereby achieving the objectives of the study.

Comparison of Dc-Dc SEPIC, CUK and Flyback Converters Based LED Drivers

2020 ◽  
pp. 99-107
Author(s):  
Erdal Sehirli
Keyword(s):  
Integrated Circuit ◽  
Closed Loop ◽  
Input Voltage ◽  
Open Loop ◽  
Current Sensor ◽  
Switching Frequency ◽  
Led Driver ◽  
Advantages And Disadvantages ◽  
Led Drivers ◽  
Conduction Mode

This paper presents the comparison of LED driver topologies that include SEPIC, CUK and FLYBACK DC-DC converters. Both topologies are designed for 8W power and operated in discontinuous conduction mode (DCM) with 88 kHz switching frequency. Furthermore, inductors of SEPIC and CUK converters are wounded as coupled. Applications are realized by using SG3524 integrated circuit for open loop and PIC16F877 microcontroller for closed loop. Besides, ACS712 current sensor used to limit maximum LED current for closed loop applications. Finally, SEPIC, CUK and FLYBACK DC-DC LED drivers are compared with respect to LED current, LED voltage, input voltage and current. Also, advantages and disadvantages of all topologies are concluded.

scholarly journals Quality Classification of Injection-Molded Components by Using Quality Indices, Grading, and Machine Learning

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 353
Author(s):  
Kun-Cheng Ke ◽  
Ming-Shyan Huang
Keyword(s):  
Machine Learning ◽  
Integrated Circuit ◽  
Quality Indices ◽  
Statistical Process ◽  
Suitable Alternative ◽  
Quality Grading ◽  
Quality Of Products ◽  
The Cost ◽  
Mlp Model

Conventional methods for assessing the quality of components mass produced using injection molding are expensive and time-consuming or involve imprecise statistical process control parameters. A suitable alternative would be to employ machine learning to classify the quality of parts by using quality indices and quality grading. In this study, we used a multilayer perceptron (MLP) neural network along with a few quality indices to accurately predict the quality of “qualified” and “unqualified” geometric shapes of a finished product. These quality indices, which exhibited a strong correlation with part quality, were extracted from pressure curves and input into the MLP model for learning and prediction. By filtering outliers from the input data and converting the measured quality into quality grades used as output data, we increased the prediction accuracy of the MLP model and classified the quality of finished parts into various quality levels. The MLP model may misjudge datapoints in the “to-be-confirmed” area, which is located between the “qualified” and “unqualified” areas. We classified the “to-be-confirmed” area, and only the quality of products in this area were evaluated further, which reduced the cost of quality control considerably. An integrated circuit tray was manufactured to experimentally demonstrate the feasibility of the proposed method.

scholarly journals A Review on Terahertz Technologies Accelerated by Silicon Photonics

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1646
Author(s):  
Jingya Xie ◽  
Wangcheng Ye ◽  
Linjie Zhou ◽  
Xuguang Guo ◽  
Xiaofei Zang ◽  
...  
Keyword(s):  
Integrated Circuit ◽  
Silicon Photonics ◽  
Large Scale ◽  
Cost Effective ◽  
Single Chip ◽  
Photonic Integrated Circuit ◽  
Hybrid Silicon ◽  
The Cost ◽  
Silicon Based ◽  
Thz Applications

In the last couple of decades, terahertz (THz) technologies, which lie in the frequency gap between the infrared and microwaves, have been greatly enhanced and investigated due to possible opportunities in a plethora of THz applications, such as imaging, security, and wireless communications. Photonics has led the way to the generation, modulation, and detection of THz waves such as the photomixing technique. In tandem with these investigations, researchers have been exploring ways to use silicon photonics technologies for THz applications to leverage the cost-effective large-scale fabrication and integration opportunities that it would enable. Although silicon photonics has enabled the implementation of a large number of optical components for practical use, for THz integrated systems, we still face several challenges associated with high-quality hybrid silicon lasers, conversion efficiency, device integration, and fabrication. This paper provides an overview of recent progress in THz technologies based on silicon photonics or hybrid silicon photonics, including THz generation, detection, phase modulation, intensity modulation, and passive components. As silicon-based electronic and photonic circuits are further approaching THz frequencies, one single chip with electronics, photonics, and THz functions seems inevitable, resulting in the ultimate dream of a THz electronic–photonic integrated circuit.

Investigation of suction flow characteristic in the inertance hydraulic converters for efficiency improvement

2021 ◽  
pp. 095965182110248
Author(s):  
Xiaoming Chen ◽  
Yuchuan Zhu ◽  
Travis Wiens ◽  
Doug Bitner ◽  
Minghao Tai ◽  
...  
Keyword(s):  
Flow Rate ◽  
Flow Characteristic ◽  
Performance Indicator ◽  
Flow Characteristics ◽  
Check Valve ◽  
Analytical Models ◽  
Switching Frequency ◽  
Experimental Measurements ◽  
Efficiency Improvement ◽  
Suction Flow

The inertance hydraulic converter relies on fluid inertance to modulate flow or pressure and is considered to be a competitive alternative to the conventional proportional hydraulic system due to its potential advantage in efficiency. As the quantification of fluid inertance, the suction flow characteristic is the crucial performance indicator for efficiency improvement. To explore the discrepancy between the passive inertance hydraulic converter featured by the check valve and the active inertance hydraulic converter driven by an equivalent 2/3 way fast switching valve in regard to suction flow characteristics, analytical models of the inertance hydraulic converters were established in MATLAB/Simulink. The validated models of the respective suction components were incorporated in the overall analytical models and their suction flow characteristics were theoretically and experimentally discussed. The analytical predictions and experimental measurements for the current configurations indicated that the active inertance hydraulic converter yields a larger transient suction flow rate than that of the passive inertance hydraulic converter due to the difference of the respective suction components. The suction flow characteristic can be modulated using the supply pressure and duty cycle, which was confirmed by experimental measurements. In addition, the suction flow characteristics are heavily affected by the resistance of the suction flow passage and switching frequency. There is a compromise between the resistance and switching frequency for inertance hydraulic converters to achieve large suction flow rate.

scholarly journals High Step-Up Converter Based on Non-Series Energy Transfer Structure for Renewable Power Applications

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 689
Author(s):  
Luis Humberto Diaz-Saldierna ◽  
Jesus Leyva-Ramos
Keyword(s):  
Power Efficiency ◽  
Common Ground ◽  
Linear Models ◽  
Efficiency Improvement ◽  
Boost Converters ◽  
Renewable Power ◽  
Current Design ◽  
Alternative Sources ◽  
Transfer Structure ◽  
Laboratory Prototype

In this paper, a high step-up boost converter with a non-isolated configuration is proposed. This configuration has a quadratic voltage gain, suitable for processing energy from alternative sources. It consists of two boost converters, including a transfer capacitor connected in a non-series power transfer structure between input and output. High power efficiencies are achieved with this arrangement. Additionally, the converter has a common ground and non-pulsating input current. Design conditions and power efficiency analysis are developed. Bilinear and linear models are derived for control purposes. Experimental verification with a laboratory prototype of 500 W is provided. The proposed configuration and similar quadratic configurations are compared experimentally using the same number of components to demonstrate the power efficiency improvement. The resulting power efficiency of the prototype was above 95% at nominal load.

Design of a High-Precision Flyback Constant Voltage AC–DC Converter

2017 ◽  
Vol 26 (11) ◽  
pp. 1750175
Author(s):  
Changyuan Chang ◽  
Chao Hong ◽  
Yang Xu ◽  
Hailong Sun ◽  
Yao Chen
Keyword(s):  
High Precision ◽  
Output Voltage ◽  
Control Method ◽  
Switching Frequency ◽  
Constant Voltage ◽  
Light Load ◽  
Wave Generator ◽  
Load Regulation ◽  
High Output

A constant voltage AC–DC converter based on the digital assistant technology is proposed in this paper, which has the advantage of high output precision. In this paper, a novel digital exponential wave generator is adopted in Constant Voltage (CV) mode to replace the normal triangle waveform to obtain a wider range of switching frequency, increasing the accuracy of output voltage under light load. The control chip is implemented based on NEC 1[Formula: see text][Formula: see text]m 5[Formula: see text]V/40[Formula: see text]V HVCMOS process, and a 5[Formula: see text]V/1.2[Formula: see text]A prototype has been built to verify the proposed control method. In PFM mode the deviation of output voltage is within [Formula: see text]% and the load regulation is [Formula: see text]%. Meanwhile, when the load jumps from light to heavy, the minimum output voltage could be maintained above 4.16[Formula: see text]V.

CONCEPTS OF ELECTRONICALLY-CONTROLLED ELECTROMECHANICAL/MECHANOELECTRICAL STEER-, AUTODRIVE- AND AUTOABSORBABLE WHEELS FOR ENVIRONMENTALLY-FRIENDLY TRI-MODE SUPERCARS

1994 ◽  
Vol 04 (04) ◽  
pp. 501-516 ◽  
Author(s):  
BOGDAN T. FIJALKOWSKI ◽  
JAN W. KROSNICKI
Keyword(s):  
Direct Current ◽  
Integrated Circuit ◽  
Environmentally Friendly ◽  
Alternating Current ◽  
Switching Frequency ◽  
Neuro Fuzzy ◽  
Interior Permanent Magnet ◽  
Application Specific Integrated Circuit ◽  
Computer Processor ◽  
Application Specific

Concepts of the electronically-controlled electromechanical/mechanoelectrical Steer-, Autodrive- and Autoabsorbable Wheels (SA2W) with their brushless Alternating Current-to-Alternating Current (AC-AC), Alternating Current-to-Direct Current-Alternating Current (AC-DC-AC) and/or Direct Current-to-Alternating Current (DC-AC)/Alternating Current-to-Direct Current (AC-DC) macroelectronic converter commutator (macro-commutator) wheel-hub motors/generators with the Application Specific Integrated Matrixer (ASIM) macroelectronic converter commutators (ASIM macrocommutators) and Application Specific Integrated Circuit (ASIC) microelectronic Neuro-Fuzzy (NF) computer (processor) controllers (ASIC NF microcontrollers) for environmentally-friendly tri-mode supercars (advanced ultralight hybrids) have been conceived by the first author and designed by both authors with the Cracow University of Technology’s Automotive Mechatronics Research and Development (R&D) Team. These electromechanical/mechanoelectrical wheel-hub motors/generators, respectively, for instance, can be composed of the outer rotor with the Interior Permanent Magnet (IPM) poles and the inner stator that has the three-phase armature winding. The macroelectronic converter commutator establishes the AC-AC cycloconverter, AC-DC rectifier-DC-AC inverter and/or DC-AC inverter/AC-DC rectifier ASIM macrocommutator. The microelectronic NF computer (processor) controller establishes the ASIC microcomputer-based NF microcontroller. By adopting continuous semiconductor bipolar electrical valves in the high-power ASIM, it has been able to increase the commutation (switching) frequency and reduce harmonic losses of the electromechanical/mechanoelectrical wheel-hub motors/generators, respectively.

Research on Multi-Mode Controller of Switching Power Supply

2014 ◽  
Vol 568-570 ◽  
pp. 1217-1220
Author(s):  
Shu Lin Liu ◽  
Li Li Qi
Keyword(s):  
Power Supply ◽  
Switching Frequency ◽  
Switching Power Supply ◽  
Load Range ◽  
Heavy Load ◽  
Operating Modes ◽  
Switching Power ◽  
Advantages And Disadvantages ◽  
Switching Losses ◽  
Light Load

In order to improve the efficiency of the switching power supply in whole load range, the controller with PWM, PFM and BURST operating modes is designed in this paper, which changes the operation mode automatically according to the load. The operating principle and the advantages and disadvantages of the three operating modes are analyzed and compared. PWM mode is used in heavy load; PFM mode is used in light load to reduce switching losses by reducing the switching frequency and BURST mode is used at the standby time to further reduce switching losses. The main control module is designed and simulation results verify the feasibility of the designed circuit.

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