• Title/Summary/Keyword: Charge Pump

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Influence of Refrigerant Charge Amount on the Performance of a Water-to-Water Type Ground Source Heat Pump with a Variation of Compressor Speed and Water Flow Rate (용량 가변 및 유량변화에 따른 지열원 물대물 열펌프 유닛의 충전량 변화에 따른 성능 특성)

  • Cho, Chan-Yong;Choi, Jong-Min
    • New & Renewable Energy
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    • v.7 no.4
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    • pp.30-36
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    • 2011
  • The objective of this study is to investigate the effects of the refrigerant charge amount on the performance of a water-to-water ground source heat pump with a variation of compressor speed and the secondary fluid flow rate. The water-to-water ground source heat pump was tested by varying refrigerant charge amount from -40% to 20% of full charge. Compressor speed was changed from 30 Hz to 75 Hz and the secondary fluid flow rate was adjusted from 6 LPM to 14 LPM. For all test conditions, EWTs of an indoor heat exchanger and an outdoor heat exchanger were maintained at standard conditions of ISO 13256-2. The slope of the COP with the variation of charge amount is much steeper at undercharged conditions than that at overcharged conditions. For all compressor speed, the variation of the system performance according to charge amounts showed the similar trends. However, the optimum charge amount of the system increased a little with an increment of compressor speed. When the secondary fluid flow rate decreased, the system was optimized at higher refrigerant charge amount conditions.

Influence of Refrigerant Charge Amount on the Performance of a Water-to-Water Heat Pump with a Variation of Compressor Speed and Water Flow Rate (압축기 용량 및 유량변화에 따른 물대물 열펌프 유닛의 충전량 변화에 따른 성능 특성)

  • Cho, Chanyong;Choi, Jong Min
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.143.1-143.1
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    • 2011
  • The objective of this study is to investigate the effects of the refrigerant charge amount on the performance of a water-to-water ground source heat pump with a variation of compressor speed and the secondary fluid flow rate. The water-to-water ground source heat pump was tested by varying refrigerant charge amount from -40% to 20% of full charge. Compressor speed was changed from 30 Hz to 75 Hz, and the secondary fluid flow rate was adjusted from 6 LPM to 14 LPM. For all test conditions, EWT of an indoor heat exchanger and an outdoor heat exchanger were maintained at standard conditions of ISO 13256-2. The slope of the COP with the variation of charge amount is much steeper at undercharged conditions than that at overcharged conditions. For all compressor speed, the variation of the system performance according to charge amounts showed the similar trends. However, the optimum charge amount of the system increased a little with an increment of compressor speed. When the secondary fluid flow rate decreased, the system optimized at higher refrigerant charge amount conditions.

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High Performance Charge Pump Converter with Integrated CMOS Feedback Circuit

  • Jeong, Hye-Im;Park, Jung-Woong;Choi, Ho-Yong;Kim, Nam-Soo
    • Transactions on Electrical and Electronic Materials
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    • v.15 no.3
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    • pp.139-143
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    • 2014
  • In this paper, an integrated low-voltage control circuit is introduced for a charge pump DC-DC boost converter. By exploiting the advantage of the integration of the feedback control circuit within CMOS technology, the charge pump boost converter offers a low-current operation with small ripple voltage. The error amplifier, comparator, and oscillator in the control circuit are designed with the supply voltage of 3.3 V and the operating frequency of 1.6~5.5 MHz. The charge pump converter with the 4 or 8 pump stages is measured in simulation. The test in the $0.35{\mu}m$ CMOS process shows that the load current and ripple ratio are controlled under 1 mA and 2% respectively. The output-voltage is obtained from 4.8 ~ 8.5 V with the supply voltage of 3.3 V.

Optimization of Heat Pump Systems (열펌프의 성능 최적화에 관한 연구)

  • Choi, Jong-Min;Yun, Rin;Kim, Yong-Chan
    • New & Renewable Energy
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    • v.3 no.4
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    • pp.22-30
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    • 2007
  • An expansion device plays an important role in optimizing the heat pumps by controlling refrigerant flow and balancing the system pressures. Conventional expansion devices are being gradually replaced with electronic expansion valves due to increasing focus on comfort, energy conservation, and application of a variable speed compressor. In addition, the amount of refrigerant charge in a heat pump is another primary parameter influencing system performance. In this study, the flow characteristics of the expansion devices are analyzed, and the effects of refrigerant charge amount on the performance of the heat pump and the variation of compressor speed are investigated at various operating conditions. Mass flow rate through capillary tube, short tube orifice, and EEV was strongly dependent on the upstream pressure and subcooling. The heat pump system is very sensitive with a variation of refrigerant charge amount. The performance of it can be optimized by adjusting the flow rate through expansion device to maintain a constant superheat at all test conditions.

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A Design of an Automatic Current Correcting Charge-Pump using Replica Charge Pump with Current Mismatch Detection (부정합 감지 복제 전하 펌프를 이용한 자동 전류 보상 전하 펌프의 설계)

  • Kim, Seong-Geun;Kim, Young-Shin;Pu, Young-Gun;Park, Joon-Sung;Hur, Jeong;Lee, Kang-Yoon
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.47 no.2
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    • pp.94-99
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    • 2010
  • This paper presents a charge pump architecture for correcting the current mismatch due to the PVT variation. In general, the current mismatch of the charge pump should be minimized to improve the phase noise and spur performance of the PLL. In order to correct the current mismatch of the charge pump, the current difference is detected by the replica charge pump and fed back into the main charge pump. This scheme is very simple and guarantees the high accuracy compared with the prior works. Also, it shows a good dynamic performance because the mismatch is corrected continuously. It is implemented in 0.13um CMOS process and the die area is $100{\mu}m\;{\times}\;160{\mu}m$. The voltage swing is from 0.2V to 1V at supply voltage of 1.2V. The charging and discharging currents are $100{\mu}A$, respectively and the current mismatch due to the PVT variation is less than 1%.

Process-Variation-Adaptive Charge Pump Circuit using NEM (Nano-Electro-Mechanical) Relays for Low Power Consumption and High Power Efficiency

  • Byeon, Sangdon;Shin, Sanghak;Song, Jae-Sang;Truong, Son Ngoc;Mo, Hyun-Sun;Lee, Seongsoo;Min, Kyeong-Sik
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.15 no.5
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    • pp.563-569
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    • 2015
  • For some low-frequency applications such as power-related circuits, NEM relays have been known to show better performance than MOSFETs. For example, in a step-down charge pump circuit, the NEM relays showed much smaller layout area and better energy efficiency than MOSFETs. However, severe process variations of NEM relays hinder them from being widely used in various low-frequency applications. To mitigate the process-variation problems of NEM relays, in this paper, a new NEM-relay charge pump circuit with the self-adjustment is proposed. By self-adjusting a pulse amplitude voltage according to process variations, the power consumption can be saved by 4.6%, compared to the conventional scheme without the self-adjustment. This power saving can also be helpful in improving the power efficiency of the proposed scheme. From the circuit simulation of NEM-relay charge pump circuit, the efficiency of the proposed scheme is improved better by 4.1% than the conventional.

High-speed charge pump circuits using weighted-capacitor and multi-path (Weighted-capacitor와 multi-path를 이용한 고속 승압 회로)

  • 김동환;오원석;권덕기;이광엽;박종태;유종근
    • Proceedings of the IEEK Conference
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    • 1998.06a
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    • pp.863-866
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    • 1998
  • In this paper two quick boosting charge pump circuits for high-speed EEPROM memory are proposed. In order to improve initial charge transfer efficiency, one uses weighted capacitors where each stage has different clock coupling capacitance, and the other uses a multi-path structure at the first stage. SPICE simulation results show that these charge pumps have improve drising-time characteristics, but their $V_{DD}$ mean currents are increased a little compared with conventioanl charge pumps. The rising time upt o 15V of the proposed charge pumps is 3 times faster than that of dickson's pump at the cost of 1.5 tiems more $V_{DD}$ mean current.rrent.

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A Study on the Optimum Design of the Charge Pump PLL with Multi-PFD (다중 위상검출기를 갖는 전하 펌프 PLL의 최적 설계에 관한 연구)

  • Jang, Young-Min;Kang, Kyung;Woo, Young-shin;Sung, Man-Young
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.271-274
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    • 2001
  • In this paper, we propose a charge pump phase-locked loop (PLL) with multi-PFD which is composed of a sequential phase frequency detector(PFD) and a precharge PFD. When the Phase difference is within - $\pi$$\pi$ , operation frequency can be increased by using precharge PFD. When the phase difference is larger than │ $\pi$ │, acquisition time can be shorten by the additional control circuit with increased charge pump current. Therefore a high frequency operation, a fast acquisition and an unlimited error detection range can be achieved.

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A Study on the Optimum Design of Charge Pump PLL for High Speed and Fast Acquisition (고속동작과 빠른 Acquisition 특성을 가지는 Charge Pump PLL의 최적설계에 관한 연구)

  • Woo, Young-Shin;Sung, Man-Young
    • Proceedings of the KIEE Conference
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    • 1999.11c
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    • pp.718-720
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    • 1999
  • This paper describes a charge pump PLL architecture which achieves high frequency operation and fast acquisition. This architecture employs multi-phase frequency detector comprised of precharge type phase frequency detector and conventional phase frequency detector. Operation frequency is increased by using precharge type phase frequency detector when the phase difference is small and acquisition time is shortened by using conventional phase frequency detector and increased charge pump current when the phase difference is large. By virtue of this multi-phase frequency detector structure, the maximum operating frequency of 694MHz at 3.0V and faster acquisition were achieved by simulation.

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A Design of Charge Pump with Up/Down Current Mismatch Compensation for PHS Application (Up/Down Current Mismatch 보상 기능을 추가한 Charge Pump 회로의 설계)

  • Kim, Sang-Woo;Park, Joon-Sung;Ko, Dong-Hyun;Pu, Young-Gun;Lee, Kang-Yoon
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.472-473
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    • 2008
  • This paper presents a charge pump used in frequency synthesizer for PHS application. The up/down current mismatch of charge pump has a critical effect on the phase noise and spur performance in frequency synthesizer. Therefore, the mismatch compensation scheme is proposed in this paper. And, the measurement results show that the mismatch can be reduced below 5 %.

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