• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.191-194
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• 1999

The balanced amplifier is a practical amplifier to, implement a broadband amplifier that has flat gain and good input and output VSWR. Three-stage amplifier design procedure usually divided into three partition satisfying the following requirements : low noise figure, high gain and high power output. FHX35LG HEMT device is used in the design can be obtained low noise figure at the first-stage, MGA82563 MMIC device is used in the design can be maintained high gain at the second-stage, and AHI MMIC device is used in the design can be required high power output at the third-stage. The results of three-stage balanced amplifier show that power gain is about 40㏈, noise figure is less than 1.2㏈ at operating frequency.

• Journal of Power Electronics
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• v.11 no.5
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• pp.734-742
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• 2011

In this paper a robust method is presented for the combined design of STATCOM and Power System Stabilizer (PSS) controllers in order to enhance the damping of the low frequency oscillations in power systems. The combined design problems among PSS and STATCOM internal ac and dc voltage controllers has been taken into consideration. The equations that describe the proposed system have been linearized and a Fuzzy Logic Controller (FLC) has been designed for the PSS. Then, the Particle Swarm Optimization technique (PSO) which has a strong ability to find the most optimistic results is employed to search for the optimal STATCOM controller parameters. The proposed controllers are evaluated on a single machine infinite bus power system with the STATCOM installed in the midpoint of the transmission line. The results analysis reveals that the combined design has an excellent capability in damping a power system's low frequency oscillations, and that it greatly enhances the dynamic stability of power systems. Moreover, a system performance analysis under different operating conditions and some performance indices studies show the effectiveness of the combined design.

• Journal of Power Electronics
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• v.14 no.3
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• pp.468-477
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• 2014

This study proposes an optimized design of a dual active bridge converter for a low-voltage charger in a military uninterrupted power supply (UPS) system. The dual active bridge converter is among various bi-directional DC/DC converters that possess a high-efficiency isolated bi-directional converter. In the general design, the zero-voltage switching(ZVS) region is reduced when the battery voltage is high. By contrast, efficiency is low because of high conduction losses when the battery voltage is low. Variable switching frequency is applied to increase the ZVS region and the power conversion efficiency, depending on battery voltage changes. At the same duty, the same power is obtained regardless of the battery voltage using the variable switching frequency. The proposed method is applied to a 5 kW prototype dual active bridge converter, and the experimental results are analyzed and verified.

• Journal of Electrical Engineering and Technology
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• v.3 no.1
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• pp.130-134
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• 2008

The increasing size of very large scale integration (VLSI) circuits, high transistor density, and popularity of low-power circuit and system design are making the minimization of power dissipation an important issue in VLSI design. Test Power dissipation is exceedingly high in scan based environments wherein scan chain transitions during the shift of test data further reflect into significant levels of circuit switching unnecessarily. Scan chain or cell modification lead to reduced dissipations of power. The ETC algorithm of previous work has weak points. Taking all of this into account, we therefore propose a new algorithm. Its name is RE_ETC. The proposed modifications in the scan chain consist of Exclusive-OR gate insertion and scan cell reordering, leading to significant power reductions with absolutely no area or performance penalty whatsoever. Experimental results confirm the considerable reductions in scan chain transitions. We show that modified scan cell has the improvement of test efficiency and power dissipations.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.626-628
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• 2004

This paper describes an 8-bit CMOS folding A/D converter for set-top box. Modular low-power, high-speed CMOS A/D converter for embedded systems aims at design techniques for low-power, high-speed A/D converter processed by the standard CMOS technology. The time-interleaved A/D converter or flash A/D converter are not suitable for the low-power applications. The two-step or multi-step flash A/D converters need a high-speed SHA, which represents a tough task in high-speed analog circuit design. On the other hand, the folding A/D converter is suitable for the low-power, high-speed applications(Embedded system). The simulation results illustrate a conversion rate of 40MSamples/s and a Power dissipation of 80mW(only analog block) at 2.5V supply voltage.

• The Journal of the Korea institute of electronic communication sciences
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• v.2 no.3
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• pp.163-167
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• 2007

In this paper, to design 8 bit RISC Microprocessor, a method of Clock Gating to reduce electric power consumption is proposed. In order to examine the priority, the comparison results of between a 8 bit Microprocessor which is not considered Low Power consumption and which is considered Low Power consumption using a methods of Clock Gating are represented. Within the a few periods, the results of comparing with a Microprocessor not considered the utilization of Clock Gating shows that the reduction of dynamic dissipation is minimized up to 21.56%.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.1
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• pp.69-77
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• 2021

The widely used low-cost design methodology for IoT devices is very popular. In such a networked device, memory is composed of flash memory, SRAM, DRAM, etc., and because it processes a large amount of data, memory design is an important factor for system performance. Therefore, each device selects optimized design factors such as function, performance and cost according to market demand. The design of a memory architecture available for low-cost IoT devices is very limited with the configuration of SRAM, flash memory, and DRAM. In order to process as much data as possible in the same space, an architecture that supports parallel processing units is usually provided. Such parallel architecture is a design method that provides high performance at low cost. However, it needs precise software techniques for instruction and data mapping on the parallel architecture. This paper proposes an instruction/data mapping method to support optimized parallel processing performance. The proposed method optimizes system performance by actively using hardware and software parallelism.

• Journal of the Microelectronics and Packaging Society
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• v.23 no.2
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• pp.37-42
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• 2016

While datacenter operation cost increases with electricity price rise, many researchers study low-power processor based supercomputers to reduce power consumption of datacenters. Reliability of low-power processors for supercomputers can be of concern since the reliability of many low-power processors are assessed based on mobile use conditions. This paper assessed the reliability of low-power processor packages based on supercomputer use conditions. Temperature cycling was determined as a critical failure cause of low-power processor packages through literature surveys and failure mode, effect and criticality analysis. The package temperature was measured at multiple processor load conditions to examine the relationship between processor load and package temperature. A physics-of-failure reliability model associated with temperature cycling predicted the expected lifetime of low-power processors to be less than 3 years. Recommendations to improve the lifetime of low-power processors were presented based on the experimental results.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.369-372
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• 1999

In this paper, we propose a new method for power estimation in nodes of multi-level combinational circuits and describe its application to the extraction of common expressions for low power design. It is assumed that each node is implemented as a complex gate and the capacitance and the switching activity of the nodes are considered in the power estimation. Extracting common expressions which is accomplished mostly by the extraction of kernels, can be transformed to the problem of rectangle covering. We describe how the newly proposed estimation method can be applied to the rectangle covering problem and show the experimental results with comparisons to the results of SIS-1.2.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.420-423
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• 2003

A low temperature difference model Stirling engine is a small Stirling engine running with several degree of temperature difference without power output. In this study, the design parameters to give maximum power are discussed. As results, the phase angle is about 100 degree, and compression ratio is 1.5% of the ratio of heat source temperatures at maximum power condition.