A Multicarrier-PWM Scheme Along With a Reconfigurable Buck Converter Imitating Multiple Times Higher Switching Frequency

2021 ◽  
Vol 68 (4) ◽  
pp. 3638-3642
Author(s):  
Amit Kumar Gupta ◽  
Madhuwanti S. Joshi ◽  
Vivek Agarwal
Keyword(s):  
Buck Converter ◽  
Switching Frequency ◽  
Multicarrier Pwm

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.

Modeling & Analysis of a Novel Adaptive Hysteresis Band Controller for Boost and Buck Converter

2017 ◽  
Vol 8 (1) ◽  
pp. 305
Author(s):  
Tanmoy Roy Choudhury ◽  
Byamakesh Nayak
Keyword(s):  
Mathematical Modeling ◽  
Filter Design ◽  
Buck Converter ◽  
Switching Frequency ◽  
Steady State Analysis ◽  
System Parameters ◽  
Modeling Analysis ◽  
The Stability ◽  
Control Methodology ◽  
Control Topology

In this paper, a new topology of Adaptive Hysteresis Band controller for Boost & Buck converter has been proposed, modeled and analyzed.  The difficulties caused in Hysteresis Band (HB) controlled dc-dc converter have been eliminated using Adaptive Hysteresis Band (AHB) controller. This novel control topology can be able to maintain the switching frequency constant unlike HB controller. Thus the filter design for the converters will become easier with this controller. Again this control methodology is a robust one as it depends upon the system parameters where there was no possibility with HB controller. The Mathematical modeling of the controller is shown in this paper, further this has been simulated using Matlab /SIMULINK to generate pulse. The steady state analysis to find the parameters and the stability condition of the converter using the dynamic behavior is also portrayed in this paper. The simulation for a Boost and a Buck converter is also shown separately using AHB controller.

scholarly journals Monolithic Integrated High Frequency GaN DC-DC Buck Converters with High Power Density Controlled by Current Mode Logic Level Signal

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1540
Author(s):  
Longkun Lai ◽  
Ronghua Zhang ◽  
Kui Cheng ◽  
Zhiying Xia ◽  
Chun Wei ◽  
...  
Keyword(s):  
Power Density ◽  
Current Mode ◽  
Buck Converter ◽  
Switching Frequency ◽  
High Power Density ◽  
Current Mode Logic ◽  
Power Stage ◽  
Amplifier Stage ◽  
Gate Driver ◽  
Logic Level

Integration is a key way to improve the switching frequency and power density for a DC-DC converter. A monolithic integrated GaN based DC-DC buck converter is realized by using a gate driver and a half-bridge power stage. The gate driver is composed of three stages (amplitude amplifier stage, level shifting stage and resistive-load amplifier stage) to amplify and modulate the driver control signal, i.e., CML (current mode logic) level of which the swing is from 1.1 to 1.8 V meaning that there is no need for an additional buffer or preamplifier for the control signal. The gate driver can provide sufficient driving capability for the power stage and improve the power density efficiently. The proposed GaN based DC-DC buck converter is implemented in the 0.25 μm depletion mode GaN-on-SiC process with a chip area of 1.7 mm × 1.3 mm, which is capable of operating at high switching frequency up to 200 MHz and possesses high power density up to 1 W/mm2 at 15 V output voltage. To the authors’ knowledge, this is the highest power density for GaN based DC-DC converter at the hundreds of megahertz range.

scholarly journals Performance Analysis of Trench Power MOSFETs in High-Frequency Synchronous Buck Converter Applications

2008 ◽  
Vol 2008 ◽  
pp. 1-9 ◽  
Author(s):  
Yali Xiong ◽  
Xu Cheng ◽  
Xiangcheng Wang ◽  
Pavan Kumar ◽  
Lina Guo ◽  
...  
Keyword(s):  
Figure Of Merit ◽  
Buck Converter ◽  
Switching Frequency ◽  
Circuit Modeling ◽  
Buck Converters ◽  
Switching Loss ◽  
Frequency Range ◽  
Power Mosfets ◽  
Conduction Loss ◽  
Obvious Benefit

This paper investigates the performance perspectives and theoretical limitations of trench power MOSFETs in synchronous rectifier buck converters operating in the MHz frequency range. Several trench MOSFET technologies are studied using a mixed-mode device/circuit modeling approach. Individual power loss contributions from the control and synchronous MOSFETs, and their dependence on switching frequency between 500 kHz and 5 MHz are discussed in detail. It is observed that the conduction loss contribution decreases from 40% to 4% while the switching loss contribution increases from 60% to 96% as the switching frequency increases from 500 KHz to 5 MHz. Beyond 1 MHz frequency there is no obvious benefit to increase the die size of either SyncFET or CtrlFET. The RDS(ON)×QG figure of merit (FOM) still correlates well to the overall converter efficiency in the MHz frequency range. The efficiency of the hard switching buck topology is limited to 80% at 2 MHz and 65% at 5 MHz even with the most advanced trench MOSFET technologies.

EFFECTS OF QUANTIZATION, DELAY AND INTERNAL RESISTANCES IN DIGITALLY ZAD-CONTROLLED BUCK CONVERTER

2012 ◽  
Vol 22 (10) ◽  
pp. 1250245 ◽  
Author(s):  
FREDY EDIMER HOYOS ◽  
DANIEL BURBANO ◽  
FABIOLA ANGULO ◽  
GERARD OLIVAR ◽  
NICOLAS TORO ◽  
...  
Keyword(s):  
Power Converters ◽  
Buck Converter ◽  
Point Of View ◽  
Control Technique ◽  
Switching Frequency ◽  
Theoretical Point ◽  
Ideal Model ◽  
Alternative Control ◽  
Digital Implementation ◽  
Steady State Stability

Zero Average Dynamics (ZAD) strategy has been reported in the last decade as an alternative control technique for power converters, and a lot of work has been devoted to analyze it. From a theoretical point of view, this technique has the advantage that it guarantees fixed switching frequency, low output error and robustness, however, no high correspondence between numerical and experimental results has been obtained. These differences are basically due to model assumptions; in particular, all elements in the circuit were modeled as ideal elements and simulations and conclusions about steady state stability and transitions to chaos have been carried out with this ideal model. Regarding the practical point of view and the digital implementation, we include in this paper internal resistances, quantization effects and 1-period delay to the model. This paper shows in an experimental and numerical way the effects of these elements to the model and their incidence in the results. Now, experimental and numerical analyses fully agree.

scholarly journals Efficiency of Synchronous and Asynchronous Buck-Converter at Low Output Current.

2019 ◽  
Vol 27 (2) ◽  
pp. 194-206
Author(s):  
Ismael Khaleel Murad
Keyword(s):  
Duty Cycle ◽  
Buck Converter ◽  
Voltage Regulator ◽  
Switching Frequency ◽  
Output Current ◽  
Load Current ◽  
Small Load ◽  
Step Down ◽  
Conduction Mode ◽  
Continuous Conduction Mode

In this paper both synchronous and asynchronous buck-converter were designed to work in continuous conduction mode “CCM” and to deliver small load current. Then the two topologies were tested in terms of efficiency at small load current by use of  different values of switching frequencies (range from 150 KHz to 1MHz) and three separated values of duty-cycle (0.4, 0.6 and 0.8).   Obtained results turns out that efficiency of both synchronous and asynchronous buck-converter “switching step-down voltage regulator” responds in a negative manner to the increase in the switching frequency. However, this impact is being stronger in synchronous topology because of magnifying effect of losses related to switching frequency compared to those related to conduction when working at small load currents; this behavior makes obtained efficiency of both topologies in convergent levels when they operated to deliver small output current especially when working with higher switching frequencies. Larger duty-cycle can rise up the efficiency of both topologies.

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.

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.

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