• Title/Summary/Keyword: Current regulator

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A new approach to the current regulator design of LED strings based on current mirror

  • Kim, Pu-Jin;Yoo, Min-Ki;Lee, Rok-Hee;Lee, Koo-Hwa;Jang, Kyeong-Kun;Kang, Sin-Ho
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.837-840
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    • 2008
  • This paper studies the current regulator of LED Backlighting system for LCD. The proposed regulator and a typical regulator are introduced. To find out the characteristics of two regulators, Prototype samples of LED Backlighting system are made. Both the proposed regulator and a typical regulator are compared with electrical, thermal and optical characteristics each viewpoint.

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Zero-Current Switching LLC Resonant Post-Regulator for Independent Multi-Output (독립된 다중출력을 위한 영전류 스위칭 LLC 공진형 Post-Regulator)

  • Cho, Sang-Ho;Yoon, Jong-Kyu;Roh, Chung-Wook;Hong, Sung-Soo;Kim, Jong-Hae;Lee, Hyo-Bum;Han, Sang-Kyu
    • The Transactions of the Korean Institute of Power Electronics
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    • v.14 no.1
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    • pp.46-53
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    • 2009
  • A new zero-current switching LLC resonant post-regulator for multi-output power system is proposed in this paper. A conventional LLC resonant converter employs extra non-isolated DC/DC converters to obtain tight-regulated multi-slave output voltages. Therefore, it has several serious problems such as a poor efficiency and high cost of production. The proposed post-regulator features low voltage and current stress across the output rectifier diodes and power switches. Moreover, the proposed post-regulator requires only one power switch instead of the bulky and expensive non-isolated DC/DC converter. Therefore, it features a simple structure and lower cost. Especially, since the proposed post-regulator can ensure the ZCS of all power switches, it has very desirable advantages such as more improved EMI characteristics and reduced switching losses. Finally, to confirm the operation, validity, and features of the proposed circuit, experimental results from a proposed zero-current LLC resonant post-regulator are presented.

Effects of Imperfect Sinusoidal Input Currents on the Performance of a Boost PFC Pre-Regulator

  • Cheung, Martin K.H.;Chow, Martin H.L.;Lai, Y.M.;Loo, K.H.
    • Journal of Power Electronics
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    • v.12 no.5
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    • pp.689-698
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    • 2012
  • This paper investigates the effects of applying different input current waveshapes on the performance of a continuous-conduction-mode (CCM) power-factor-correction (PFC) boost pre-regulator. It is found that the output voltage ripple of the pre-regulator can be reduced if the input current is modified to include controlled amount of higher order harmonics. This finding allows us to balance the performance of output regulation and the harmonic current emission when coming to the design of the pre-regulator. An experimental PFC boost pre-regulator prototype is constructed to verify the analysis and show the benefit of the pre-regulator operating with input current containing higher order harmonics.

LDO regulator with improved regulation characteristics using gate current sensing structure (게이트 전류 감지 구조를 이용한 향상된 레귤레이션 특성의 LDO regulator)

  • Jun-Mo Jung
    • Journal of IKEEE
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    • v.27 no.3
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    • pp.308-312
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    • 2023
  • The gate current sensing structure was proposed to more effectively control the regulation of the output voltage when the LDO regulator occurs in an overshoot or undershoot situation. In a typical existing LDO regulator, the regulation voltage changes when the load current changes. However, the operation speed of the pass transistor can be further improved by supplying/discharging the gate terminal current in the pass transistor using a gate current sensing structure. The input voltage of the LDO regulator using the gate current sensing structure is 3.3 V to 4.5 V, the output voltage is 3 V, and the load current has a maximum value of 250 mA. As a result of the simulation, a voltage change value of about 12 mV was confirmed when the load current changed up to 250 mA.

A Fast Response Integrated Current-Sensing Circuit for Peak-Current-Mode Buck Regulator

  • Ha, Jung-Woo;Park, Byeong-Ha;Kong, Bai-Sun;Chun, Jung-Hoon
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.14 no.6
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    • pp.810-817
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    • 2014
  • An on-chip current sensor with fast response time for the peak-current-mode buck regulator is proposed. The initial operating points of the peak current sensor are determined in advance by the valley current level, which is sensed by a valley current sensor. As a result, the proposed current sensor achieves a fast response time of less than 20 ns, and a sensing accuracy of over 90%. Applying the proposed current sensor, the peak-current-mode buck regulator for the mobile application is realized with an operating frequency of 2 MHz, an output voltage of 0.8 V, a maximum load current of 500 mA, and a peak efficiency of over 83%.

High Efficiency Multi-Channel LED Driver IC with Low Current-Balance Error Using Current-Mode Current Regulator

  • Yoon, Seong-Jin;Cho, Je-Kwang;Hwang, In-Chul
    • Journal of Electrical Engineering and Technology
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    • v.12 no.4
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    • pp.1593-1599
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    • 2017
  • This paper presents a multi-channel light-emitting diode (LED) driver IC with a current-mode current regulator. The proposed current regulator replaces resistors for current sensing with a sequentially controlled single current sensor and a single regulation loop for sensing and regulating all LED channel currents. This minimizes the current mismatch among the LED channels and increases voltage headroom or, equivalently, power efficiency. The proposed LED driver IC was fabricated in a $0.35-{\mu}m$ BCD 60-V high voltage process, and the chip area is $1.06mm^2$. The measured maximum power efficiency is 93.4 % from a 12-V input, and the inter-channel current error is smaller than as low as ${\pm}1.3%$ in overall operating region.

250 mV Supply Voltage Digital Low-Dropout Regulator Using Fast Current Tracking Scheme

  • Oh, Jae-Mun;Yang, Byung-Do;Kang, Hyeong-Ju;Kim, Yeong-Seuk;Choi, Ho-Yong;Jung, Woo-Sung
    • ETRI Journal
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    • v.37 no.5
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    • pp.961-971
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    • 2015
  • This paper proposes a 250 mV supply voltage digital low-dropout (LDO) regulator. The proposed LDO regulator reduces the supply voltage to 250 mV by implementing with all digital circuits in a$0.11{\mu}m$ CMOS process. The fast current tracking scheme achieves the fast settling time of the output voltage by eliminating the ringing problem. The over-voltage and under-voltage detection circuits decrease the overshoot and undershoot voltages by changing the switch array current rapidly. The switch bias circuit reduces the size of the current switch array to 1/3, which applies a forward body bias voltage at low supply voltage. The fabricated LDO regulator worked at 0.25 V to 1.2 V supply voltage. It achieved 250 mV supply voltage and 220 mV output voltage with 99.5% current efficiency and 8 mV ripple voltage at $20{\mu}A$ to $200{\mu}A$ load current.

Development of Voltage Regulator and Pulse Charger Using Pulse Current for Reuse of the Waste Lead Acid Battery (폐납축전지 재활용을 위한 펄스전류에 의한 전압조정기와 펄스충전기의 개발)

  • Shin, Choon-Shik;An, Young-Joo;Kim, Dong-Wan
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.56 no.2
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    • pp.65-73
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    • 2007
  • In this study, the pulse charger and voltage regulator are proposed that can reuse the waste lead acid battery. The first we develop the voltage regulator that can reuse the waste lead battery. And the pulse current is applied to the terminal of the waste lead acid battery. The voltage regulator is available principle of the pulse current which can reduce the sulfate to incipient material such as Pb and PbO2. Therefore the internal resistance of the lead acid battery is decreased, the performance of the lead acid battery is improved and the durability is prolonged. The second we develop the pulse charger using the voltage regulator. The pulse charger uses the switch mode of the forward convert method. The pulse charger maintain the constant voltage in state removing the lead acid battery and when it connected the pulse charger, it is converted the charge mode of the constant current immediately. It continues the rapid charge until the full state of the lead acid battery. After that the pulse charger is converted to the charge mode of constant voltage automatically, and then it continues the normal charge. The experiment results show that the effectiveness of the voltage regulator and pulse charger such as the good performance and the prolonged durability in lead acid battery of the small and large capacity.

Slew-Rate Enhanced Low-Dropout Regulator by Dynamic Current Biasing

  • Jeong, Nam Hwi;Cho, Choon Sik
    • Journal of electromagnetic engineering and science
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    • v.14 no.4
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    • pp.376-381
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    • 2014
  • We present a CMOS rail-to-rail class-AB amplifier using dynamic current biasing to improve the delay response of the error amplifier in a low-dropout (LDO) regulator, which is a building block for a wireless power transfer receiver. The response time of conventional error amplifiers deteriorates by slewing due to parasitic capacitance generated at the pass transistor of the LDO regulator. To enhance slewing, an error amplifier with dynamic current biasing was devised. The LDO regulator with the proposed error amplifier was fabricated in a $0.35-{\mu}m$ high-voltage BCDMOS process. We obtained an output voltage of 4 V with a range of input voltages between 4.7 V and 7 V and an output current of up to 212 mA. The settling time during line transient was measured as $9{\mu}s$ for an input variation of 4.7-6 V. In addition, an output capacitor of 100 pF was realized on chip integration.

A Study on the Design of ESD Protection Circuit for Prevention of Destruction and Efficiency of LDO Regulator (LDO 레귤레이터의 파괴방지 및 효율성을 위한 ESD 보호회로 설계에 대한 연구)

  • Jeong-Min Lee;Sang-Wook Kwon;Seung-Hwan Baek;Yong-Seo Koo
    • Journal of IKEEE
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    • v.27 no.3
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    • pp.258-264
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    • 2023
  • This paper proposes an LDO regulator with a built-in ESD (Electro Static Discharge) protection circuit to effectively operate and prevent destruction of the LDO (Low Drop Out) regulator according to the load current. The proposed LDO regulator can more effectively adjust the gate node voltage of the pass transistor according to the output voltage of the LDO regulator by using an additional feedback current circuit structure. In addition, it is expected to have high reliability for the ESD situation by embedding a new structure that increases the holding voltage by about 2V by reducing the current gain on the SCR loop by adding a P+ bridge to the existing ESD protection device.