scholarly journals A Novel Buck Converter with Constant Frequency Controlled Technique

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5911
Author(s):  
Hsiao-Hsing Chou ◽  
Hsin-Liang Chen
Keyword(s):  
Output Voltage ◽  
Maximum Load ◽  
Buck Converter ◽  
Design Concept ◽  
Frequency Variation ◽  
Switching Frequency ◽  
Circuit Realization ◽  
Constant Frequency ◽  
Scheme Design ◽  
Control Scheme

This paper presents a buck converter with a novel constant frequency controlled technique, which employs the proposed frequency detector and adaptive on-time control (AOT) logic to lock the switching frequency. The control scheme, design concept, and circuit realization are presented. In contrast to a complex phase lock loop (PLL), the proposed scheme is easy to implement. With this novel technique, a buck converter is designed to produce an output voltage of 1.0–2.5 V at the input voltage of 3.0–3.6 V and the maximum load current of 500 mA. The proposed scheme was verified using SIMPLIS and MathCAD. The simulation results show that the switching frequency variation is less than 1% at an output voltage of 1.0–2.5 V. Furthermore, the recovery time is less than 2 μs for a step-up and step-down load transient. The circuit will be fabricated using UMC 0.18 μm 1P6M CMOS processes. The control scheme, design concept and circuit realization are presented in this paper.

scholarly journals Adaptive On-Time Buck Converter with Wave Tracking Reference Control for Output Regulation Accuracy

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3809
Author(s):  
Pang-Jung Liu ◽  
Mao-Hui Kuo
Keyword(s):  
Output Voltage ◽  
Output Regulation ◽  
Buck Converter ◽  
Maximum Efficiency ◽  
Frequency Variation ◽  
Switching Frequency ◽  
Maximum Output ◽  
Equivalent Series Resistance ◽  
Load Current ◽  
Dc Offset

A ripple-based constant on-time (RBCOT) buck converter with a virtual inductor current ripple (VICR) control can relax the stability constraint of large equivalent series resistance (ESR) at an output capacitor, but output regulation accuracy deteriorates due to the issue with output DC offset. Thus, this paper proposes a wave tracking reference (WTR) control to improve converter stability with low ESR and concurrently eliminate output DC offset on the regulated output voltage. Moreover, an adaptive on-time (AOT) circuit is presented to suppress the switching frequency variation with load current changes in continuous conduction mode. A prototype chip was fabricated in 0.35 µm CMOS technology for validation. The measurement results demonstrate that the maximum output DC offset is 4.1 mV and the output voltage ripple is as small as 3 mV. Furthermore, the switching frequency variation with the AOT circuit is 11 kHz when load current changes from 50 mA to 500 mA, and the measured maximum efficiency is 90.9% for the maximum output power of 900 mW.

scholarly journals The study on the effect of voltage ripple on multiphase buck converters with phase shedding control scheme for SCADA applications

2021 ◽  
Vol 10 (4) ◽  
pp. 1856-1863
Author(s):  
Mini P. Varghese ◽  
A. Manjunatha ◽  
T. V. Snehaprabha
Keyword(s):  
Output Voltage ◽  
Low Voltage ◽  
Input Voltage ◽  
Buck Converter ◽  
Switching Frequency ◽  
Power Sources ◽  
Voltage Regulator Modules ◽  
Voltage Ripple ◽  
Control Scheme ◽  
Enhance Efficiency

Voltage regulator modules (VRM) need to have low output voltage ripple and tight efficiency to power advanced microprocessors. This paper explains a phase shedding technique to enhance efficiency and its impact on output voltage ripple. In this study, analysis was done on a 4-phase buck converter which is having an input voltage of 45-65 V and delivers an output of 9 V, 12A with a switching frequency of 200Khz. The phase shedding control scheme is suitable for applications such as power sources for programmable logic controllers, which is a part of SCADA systems, which requires a low voltage and high current power supply. Working of a multiphase buck converter with phase shedding is modelled and verified using Matlab/Simulink software. The simulation results show the effect of the phase shedding technique on efficiency in varying load conditions and the effect of an increase of the voltage ripple at the output.

scholarly journals Novel Step-Down DC–DC Converters Based on the Inductor–Diode and Inductor–Capacitor–Diode Structures in a Two-Stage Buck Converter

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1131 ◽  
Author(s):  
Mauricio Dalla Vecchia ◽  
Giel Van den Broeck ◽  
Simon Ravyts ◽  
Johan Driesen
Keyword(s):  
Output Voltage ◽  
Buck Converter ◽  
Switching Frequency ◽  
Two Stage ◽  
Voltage Level ◽  
Multiple Strategies ◽  
Power Electronics Converters ◽  
Load Demand ◽  
Duty Cycles ◽  
Step Down

This paper explores and presents the application of the Inductor–Diode and Inductor-Capacitor-Diode structures in a DC–DC step-down configuration for systems that require voltage adjustments. DC micro/picogrids are becoming more popular nowadays and the study of power electronics converters to supply the load demand in different voltage levels is required. Multiple strategies to step-down voltages are proposed based on different approaches, e.g., high-frequency transformer and voltage multiplier/divider cells. The key question that motivates the research is the investigation of the aforementioned Inductor–Diode and Inductor–Capacitor–Diode, current multiplier/divider cells, in a step-down application. The two-stage buck converter is used as a study case to achieve the output voltage required. To extend the intermediate voltage level flexibility in the two-stage buck converter, a second switch was implemented replacing a diode, which gives an extra degree-of-freedom for the topology. Based on this modification, three regions of operation are theoretically defined, depending on the operational duty cycles δ2 and δ1 of switches S2 and S1. The intermediate and output voltage levels are defined based on the choice of the region of operation and are mapped herein, summarizing the possible voltage levels achieved by each configuration. The paper presents the theoretical analysis, simulation, implementation and experimental validation of a converter with the following specifications; 48 V/12 V input-to-output voltage, different intermediate voltage levels, 100 W power rating, and switching frequency of 300 kHz. Comparisons between mathematical, simulation, and experimental results are made with the objective of validating the statements herein introduced.

scholarly journals A Fast and Simple Fault Diagnosis Method for Interleaved DC-DC Converters Based on Output Voltage Analysis

Electronics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1451
Author(s):  
Po Li ◽  
Xiang Li ◽  
Tao Zeng
Keyword(s):  
Output Voltage ◽  
High Efficiency ◽  
Tidal Energy ◽  
Open Circuit ◽  
Buck Converter ◽  
Switching Frequency ◽  
Harmonic Amplitude ◽  
Non Invasive ◽  
New Energy ◽  
Diagnosis Method

Interleaved DC-DC converters have been widely used in power conversion due to their high efficiency and reliability. In the application of new energy, this plays an increasingly important role in the grid-connected power generation of wind, solar, and tidal energy. Therefore, it is crucial to ensure the reliability and proper operation of interleaved DC-DC converters. We studied an open circuit fault (OCF) diagnosis method for a three-phase interleaved buck converter. We propose a non-invasive diagnosis method based on the output voltage using the harmonic amplitude and phase at the switching frequency as the diagnostic criteria. Evaluation was carried out on a hardware-in-the-loop (HIL) test platform to prove the validity of the proposed method. The results show that the presented method had high accuracy and robustness against OCFs, which could otherwise damage the system.

scholarly journals Equivalent Two Switches and Single Switch Buck/Buck-Boost Circuits for Solar Energy Harvesting Systems

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 583
Author(s):  
Ehsan Jamshidpour ◽  
Slavisa Jovanovic ◽  
Philippe Poure
Keyword(s):  
Output Voltage ◽  
Experimental Tests ◽  
Buck Converter ◽  
Maximum Power ◽  
Duty Ratio ◽  
Switching Frequency ◽  
Level Control ◽  
Voltage Level ◽  
Synchronous Control ◽  
Solar Energy Harvesting

In this paper, a comparative analysis has been presented of two equivalent circuits of non-isolated buck/buck-boost converters under synchronous control, used in a stand-alone Photovoltaic-battery-load system. The first circuit consists of two cascaded buck and buck-boost classical converters with two controllable switches. The buck converter is used to extract the maximum power of the Photovoltaic source, and the buck-boost converter is applied for the output voltage level control. The second circuit consists of a proposed converter with a single controllable switch. In both cases, the switching frequency is used to track the maximum power point and the duty ratio controls the output voltage level. Selected simulation results and experimental tests confirm that the two conversion circuits have identical behavior under synchronous control. This study shows that the single switch converter has a lower size and cost, but it is limited in the possible control strategy.

A 0.016 mV/mA Cross-Regulation 5-Output SIMO DC–DC Buck Converter Using Output-Voltage-Aware Charge Control Scheme

2018 ◽  
Vol 33 (11) ◽  
pp. 9619-9630 ◽  
Author(s):  
Ngoc-Son Pham ◽  
Taegeun Yoo ◽  
Tony Tae-Hyoung Kim ◽  
Chan-Gun Lee ◽  
Kwang-Hyun Baek
Keyword(s):  
Output Voltage ◽  
Buck Converter ◽  
Charge Control ◽  
Control Scheme

scholarly journals Design buck converter with variable switching frequency by using matlab simulink simulation

2020 ◽  
Vol 1 (1) ◽  
pp. 1-6
Author(s):  
Norazila Binti Md Posdzi ◽  
Norsa’adah Binti Mahmor ◽  
Rasidah Binti Abdul Rani
Keyword(s):  
Output Voltage ◽  
Current Mode ◽  
Buck Converter ◽  
Switching Frequency ◽  
Resistive Load ◽  
Current Waveform ◽  
Matlab Simulink ◽  
Simulink Simulation ◽  
Continuous Current ◽  
Continuous Current Mode

This paper presents the design of a buck converter circuit with different input switching frequency by using Matlab Simulink software. This study focuses on defining the suitable value of the inductor and capacitor to be used in the buck converter with 100VDC supply input, where the input switching frequency is use 5kHz and 25kHz. This is because the input switching frequency of a buck converter affects many aspects of circuit functionality. This design of the circuit used 20% of the duty cycle, and inductor value is 25% of Lmin to ensure the operation is in continuous current mode. The evaluation of inductor current and switching frequency used in the circuit and parameters for this analysis based on the output voltage, inductor voltage and inductor current waveform. The design of the circuit verified by simulation and results compared with the theoretical. In addition, the appropriate input switching frequency between 5kHz and 25kHz has been determined in order to use in the buck converter circuit for 100Ω resistive load.

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