scholarly journals Performance Modelling and Design Techniques for Efficiency Improvement in On-chip Switched-Capacitor DC-DC Converter

Author(s):  
Sunita Saini ◽  
Davinder Singh Saini

Abstract Fundamental charge vector method analysis is a single parameter optimization technique limited to conduction loss assuming all frequency-dependent switching (parasitic) loss negligible. This paper investigates a generalized structure to design DC-DC SC converters based on conduction and switching loss. A new technique is proposed to find the optimum value of switching frequency and switch size to calculate target load current and output voltage that maximize the efficiency. The analysis is done to identify switching frequency and switch size for two-phase 2:1 series-parallel SC converter for a target load current of 2.67mA implemented on a 22nm technology node. Results show that a minimum of 250MHz switching frequency is required for target efficiency more than 90% and the output voltage greater than 0.85V where the switch size of a unit cell corresponds to 10Ω on-resistance. MATLAB and PSpice simulation tools are used for results and validation.

2008 ◽  
Vol 2008 ◽  
pp. 1-9 ◽  
Author(s):  
Yali Xiong ◽  
Xu Cheng ◽  
Xiangcheng Wang ◽  
Pavan Kumar ◽  
Lina Guo ◽  
...  

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.


Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3288 ◽  
Author(s):  
Zhenxing Zhao ◽  
Qianming Xu ◽  
Yuxing Dai ◽  
Hanhang Yin

In battery charging applications, the charger changes its output voltage in a wide range during the charging process. This makes the design of LLC converters difficult to be optimized between the efficiency and the gain range. In this paper, an improved resonant transformer is presented for LLC resonant converter charger to improve the gain adjustment and charger efficiency. The resonant inductance and magnetizing inductance are integrated in the designed LLC transformer, and the magnetizing inductance can be adjusted dynamically with the change of output voltage and load, which is realized by a switch-controlled inductor (SCI) parallel to the secondary winding of transformer. The proposed transformer has 22.4% reduction in losses under full load conditions compared to conventional solutions. Moreover, the conduction loss and switching loss of LLC resonant tank are reduced by dynamically adjusting the magnetizing inductance, which improves the comprehensive efficiency of the whole charging process. The proposed transformer design is verified on a 720 W prototype.


Author(s):  
А.М. САЖНЕВ ◽  
Л.Г. РОГУЛИНА

Разработана модель имитационных испытаний электронного устройства в современной программной среде на основе отечественных компонентов. Проведены имитационные испытания конвертора напряжения на 24 В с выходным током 1,4 А, частотой коммутации 20 кГц и выпрямительного устройства с выходным напряжением 48 В, током нагрузки 28 А. Получены частотные зависимости уровней кондуктивных помех и выполнена их оценка на соответствие нормам. A model of simulation tests of an electronic device in a modern software environment based on domestic components has been developed. Simulation tests of a 24 V voltage converter with an output current of 1.4 A, a switching frequency of 20 kHz, and a rectifier device with an output voltage of 48 V, a load current of 28 A were carried out. The frequency dependences of conductive interference levels were obtained and their compliance with the standards was evaluated.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3809
Author(s):  
Pang-Jung Liu ◽  
Mao-Hui Kuo

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.


Author(s):  
A. A. Bakar ◽  
A. Ponniran ◽  
T. Taufik

<span>This paper presents the simulation design of dc/dc interleaved boost converter with zero-voltage switching (ZVS). By employin the interleaved structure, the input current stresses to switching devices were reduced and this signified to a switching conduction loss reduction. All the parameters had been calculated theoretically. The proposed converter circuit was simulated by using MATLAB/Simulink and PSpice software programmes. The converter circuit model, with specifications of output power of 200 W, input voltage range from 10~60 V, and operates at 100 kHz switching frequency was simulated to validate the designed parameters. The results showed that the main switches of the model converter circuit achieved ZVS conditions during the interleaving operation. Consequently, the switching losses in the main switching devices were reduced. Thus, the proposed converter circuit model offers advantages of input current stress and switching loss reductions. Hence, based on the designed parameters and results, the converter model can be extended for hardware implementation.</span>


2013 ◽  
Vol 61 (4) ◽  
pp. 787-791
Author(s):  
J. Dawidziuk

Abstract This paper presents a dual inductor-fed boost converter with an auxiliary transformer and voltage doubler for sustainable energy power converters. The new topology integrates a two-phase boost converter and a dual inductor-fed boost converter. The energy stored and transferred by both inductors can attain a wide input-voltage and load range which uses a constant switching frequency, by controlling the time duration of the simultaneous conduction of the two switches. Among other current-fed type boost converters the presented topology is attractive due to the high voltage conversion ratio, less stress on the components and less switch conduction loss. To verify the feasibility of this topology, the principles of operation, theoretical analysis, and experimental waveforms are presented for a 1 kW prototype.


To overcome the limitations of conventional multilevel inverter such as of more no. of power semiconductor switches, large no. of capacitors, more switching loss etc. , a new topology of Envelope type (E-type) MLI is used. This E-type Module has some preferable features like reduced no. of components and low switching frequency. This E-type asymmetric converter uses four unequal DC sources and ten switches to generate 13 level of output voltage. SHE modulation technique is used to achieve high quality output voltage with low harmonic content. This E-type converter configuration will be used in transformer less traction drive. Nowadays Induction motors are used as electric drives for most of the electric railways. A transformer less connection is used for feeding Induction motor. This converter-inverter configuration will convert single phase AC voltage to DC and again this DC voltage will be converted into three phase AC. The output of the E-type Multi level inverter will be used to drive the Induction motors.


Electronics ◽  
2021 ◽  
Vol 10 (14) ◽  
pp. 1623
Author(s):  
Bor-Ren Lin

In order to realize emission-free solutions and clean transportation alternatives, this paper presents a new DC converter with pulse frequency control for a battery charger in electric vehicles (EVs) or light electric vehicles (LEVs). The circuit configuration includes a resonant tank on the high-voltage side and two variable winding sets on the output side to achieve wide output voltage operation for a universal LEV battery charger. The input terminal of the presented converter is a from DC microgrid with voltage levels of 380, 760, or 1500 V for house, industry plant, or DC transportation vehicle demands, respectively. To reduce voltage stresses on active devices, a cascade circuit structure with less voltage rating on power semiconductors is used on the primary side. Two resonant capacitors were selected on the resonant tank, not only to achieve the two input voltage balance problem but also to realize the resonant operation to control load voltage. By using the variable switching frequency approach to regulate load voltage, active switches are turned on with soft switching operation to improve converter efficiency. In order to achieve wide output voltage capability for universal battery charger demands such as scooters, electric motorbikes, Li-ion e-trikes, golf carts, luxury golf cars, and quad applications, two variable winding sets were selected to have a wide voltage output (50~160 V). Finally, experiments with a 1 kW rated prototype were demonstrated to validate the performance and benefits of presented converter.


2021 ◽  
Vol 11 (2) ◽  
pp. 22
Author(s):  
Umberto Ferlito ◽  
Alfio Dario Grasso ◽  
Michele Vaiana ◽  
Giuseppe Bruno

Charge-Based Capacitance Measurement (CBCM) technique is a simple but effective technique for measuring capacitance values down to the attofarad level. However, when adopted for fully on-chip implementation, this technique suffers output offset caused by mismatches and process variations. This paper introduces a novel method that compensates the offset of a fully integrated differential CBCM electronic front-end. After a detailed theoretical analysis of the differential CBCM topology, we present and discuss a modified architecture that compensates mismatches and increases robustness against mismatches and process variations. The proposed circuit has been simulated using a standard 130-nm technology and shows a sensitivity of 1.3 mV/aF and a 20× reduction of the standard deviation of the differential output voltage as compared to the traditional solution.


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