• Journal of Power Electronics
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• v.19 no.3
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• pp.676-690
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• 2019

This paper presents a switched capacitor (SC) based bidirectional dc-dc converter topology for high voltage gain applications. The proposed converter is able to operate with multiple integral voltage conversion ratios based on user input. The architecture of a user-friendly, inductor-less multi-voltage-gain bidirectional dc-dc converter is proposed in this study. The inductor-less or magnetic-less design of the proposed converter makes it effective in higher temperature applications. Furthermore, the proposed converter has a reduced component count and lower voltage stress across its switches and capacitors when compared to existing SC converters. An output impedance analysis of the proposed converter is presented and compared with popular existing SC converters. The proposed converter is simulated in the OrCAD PSpice environment and the obtained results are presented. A 200 W hardware prototype of the proposed SC converter has been developed. Experimental results are presented to validate the efficacy of the proposed converter.

• Journal of Power Electronics
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• v.19 no.1
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• pp.1-10
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• 2019

Current imbalance is the main factor affecting the lifespan of light-emitting diode (LED) lighting systems and is generally solved by active or passive approaches. Given many new lighting applications, independent control is particularly important in achieving different levels of luminance. Existing passive and active approaches have their own limitations in current sharing and independent control, which bring new challenges to the design of LED drivers. In this work, a multichannel resonant converter based on switched-capacitor control (SCC) is proposed for solving this challenge. In the resonant network of the upper and lower half-bridges, SCC is used instead of fixed capacitance. Then, the individual current of the LED array is obtained through regulation of the effective capacitance of the SCC under a fixed switching frequency. In this manner, the complexity of the control unit of the circuit and the precision of the multichannel outputs are further improved. Finally, the superior performance of the proposed LED driver is verified by simulations and a 4-channel experimental prototype with a rated output power of 20 W.

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.4
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• pp.477-483
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• 1986

This paper studies the design of a CMOS operational amplifier for the switched capacitor filter by computer simulation, and presents the results of measurement. The operational amplifier composed of two stages is fabricated in the CMOS digital process. The DC voltage gain of the operational amplifier is 66dB, and the unity gain bandwidth is 833kHz. These results satisfy the performance requirmance requirements for the operational amplifier of the switched capacitor filter.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.381-382
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• 2020

In the battery energy storage system, battery cells are connected in series to increase the operating voltage. Due to the difference in characteristics, the performance degradation of cells is dissimilar. This paper proposes an online DC internal impedance estimation for battery cells in the series string using a matrix-switched capacitor converter, which is already verified as useful for the series balancing of the cells. The simulation in the hardware in the loop test rig shows good accuracy and the feasibility of the proposed method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.4 no.1
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• pp.25-31
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• 1979

All the resitors in the active RC filter networks can be relplaced by the switched capacitors. Therefore, An SC filter circuit can be fully integrated using MOS technology. A switched capacitor is much better than a resistor in temperature and linearity characteristics, and the former can be fabricated on the much smaller area then the latter. In this paper, It is given the generalized disign method of the active SC filter from the active RC filter using Bilinear Z-transformation. By SC filtering Techniques using Bilinear Z-transform, It enalbes us to realize the FDNR and Gyrator filters, which could not be realized in the exsisting designs, and it permits the processing of signals at much higher frequenies that many previous designs do. Experiments show that the response of the SC active filter is similiar to that of its prototype active RC filter.

• Journal of Information Display
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• v.9 no.2
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• pp.9-13
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• 2008

A novel push-pull voltage converter structure, using a switched capacitor type voltage doubler, is proposed. The circuit is constructed with a two-stage push-pull voltage doubler that has a stable operation with small output ripple. The two-stage voltage doubler creates the output voltage 4Vdd. The high clock signal is cross-coupled to the input of the second stage with the opposite phase to reduce two switching transistors and capacitors. Simulation results verify that even with a reduced number of transistor and capacitor, there is no circuit performance loss. Adding one capacitor and two switching transistors the circuit can be changed to eight times of Vdd maker.

• Journal of Power Electronics
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• v.17 no.5
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• pp.1195-1202
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• 2017

This paper presents a novel topology named a modified capacitor-assisted Z-source inverter (MCA-ZSI) based on the traditional ZSI. The impedance network of the proposed MCA-ZSI consists of two symmetrical cells coupled with two capacitors with an X-shape structure, and each cell has two inductors, two capacitors, and one diode. Compared with other topologies based on switched ZSI with the same number of components used at impedance network, the proposed topology provides higher boost ability, lower voltage stress across inverter switching devices, and lower capacitor voltage stress. The improved performances of the proposed topology are demonstrated in the simulation and experimental results.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.52 no.4
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• pp.148-153
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• 2003

In this paper, the low voltage 3V Sigma-Delta Digital Analog Converter(DAC) is designed for using in the transmitter of ADSL analog front-end. We have developed the CMOS DAC according to ANSI T1.413-2(DMT) standard specifications of the chip. The designed 4th-order DAC is composed of three block which are 1-bit DAC, 1st-order Switched-Capacitor filter and analog active 2nd-order Resistor-Capacitor(RC) filter. The HSPICE simulation of the designed DAC showing 65db SNR, is connected with 1.1MHz continuous lowpass filter. And also, we have performed the circuits verification and layout verification(ERC, DRC, LVS) followed by fabrication using TSMC 2-poly 5-metal p-substrate CMOS $0.35{\mu}m$ processing parameter. Finally, the chip testing has been performed and presented in the results.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1521-1524
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• 1987

The performance of SCF can be improved with the Op-AMP which has the properties of high speed, large slew rate, and lower power dissipation. The OP-AMP used for SCF will be presented. For illustration, using this OP-AMP 5-th order LPF is designed.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.1896-1898
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• 1998

Balanced differential SCF with common-mode reject fully differential SC network is introduced. Through simulation, performance of balanced differential bandpass SCF and its potentiality of practical application is proposed.