LDO线性恒流型高亮度LED驱动的研究与设计
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摘要
高亮度LED(发光二极管)作为光源具有发光强度大、发光效率高、节能环保、寿命长等优点,被认为是21世纪最具发展潜力的新光源,广泛应用于汽车照明、显示器、相机用闪光灯、面板背光源、景光照明和室内装饰等照明领域。为了充分发挥高亮度LED的优势,良好的驱动是不可或缺的,世界知名半导体器件公司纷纷开发出各种新型高亮度LED驱动芯片以满足市场的需要,高亮度LED驱动芯片是目前电源管理芯片市场的研究热点。
对于蓄电池供电的汽车照明等领域的高亮度LED,低压差线性恒流型LED驱动由于具有结构简单、电磁干扰(EMI)与噪声低、响应迅速、尺寸小及成本低等优点,是性价比较高的设计方案。论文主要讨论了一种高压、350mA、低压差线性恒流型高亮度LED驱动芯片的研究与设计。设计先按照芯片需完成的功能,确定系统的结构与电路划分,然后结合“自底向上”的原理图输入设计方法对部分电路进行设计,最后根据系统设计的框架对各电路进行协调设计,并进行芯片的整体性能验证。本文的研究重点在于低压差线性恒流型高亮度LED驱动芯片的总体设计与线性恒流型驱动的效率改进,详细介绍了芯片中带隙基准与稳压输出、误差放大器、过热保护等子电路的设计过程,并给出了相应的仿真结果和分析。
在前面研究的基础上,采用Jazz 0.5μm BCD制造工艺完成了一款低压差线性恒流型高亮度LED驱动芯片的前端与后端设计。芯片后仿真结果表明,芯片可工作于汽车电子级宽输入电源电压范围(+6.3V~+32V)与宽温度范围(-40℃~+125℃);具有过热保护、过流保护、PWM亮度调节使能控制、204mV低电流检测基准等功能;在+12V电源电压下输出电流精度在±2.86%以内,实现典型值为0.5V的低压差设计;另外,对线性恒流型高亮度LED驱动的优化设计有效地提高了芯片效率。后仿真结果表明芯片的设计指标达到既定的要求。
High Brightness LED as the most promising light source has many advantages, such as high luminous efficiency, high luminous intensity, economical and safety for environment, long life period etc. It is widely used in automotive illumination, display, the flash on cell-phone camera, back lighting of panel and other illuminating applications. The HB LED driver is indispensable, and become the star of power management research. Providing constant current is the major task. For its briefness, low noise and EMI, fast transient response, mini bulk and inexpensive, linear current regulator is well suited for illuminating fields using storage battery as power supply, such as automotive illumination. In this thesis, the research and design of a high voltage, 350 mA, LDO linear current regulative HB LED driver is demonstrated. According to the functions the IC should have, the structure and functional blocks of the system were determined, then the direct schematic design of some subcircuits had also been conducted in reference to other function-like circuits, using the“Bottom-to-up”methodology. Then, the whole chip simulation and verification were conducted to examine the matching between the design and the requirements of specification. The thesis put emphasis on the whole design of the chip and improvement on efficiency of the linear current regulator, especially on the design of some critical blocks, such as reference and voltage regulator block, error amplifier block and thermal protect block.
On the basis of above research, a LDO linear current regulative HB LED driver is designed and fabricated in Jazz 0.5μm BCD process. Simulation results show that the chip can achieve±2.86% output current accuracy and 0.5V low-dropout voltage, and it features the functions of over temperature protection, over current limiting, PWM dimming at output current as well as low 204 mV current-sense reference. Besides, optimization design for the LED driver improved the efficiency effectively. The post simulation has proved that the circuit works very well and every electrical characteristic meets the specification of the data sheet which proves a successful design.
对于蓄电池供电的汽车照明等领域的高亮度LED,低压差线性恒流型LED驱动由于具有结构简单、电磁干扰(EMI)与噪声低、响应迅速、尺寸小及成本低等优点,是性价比较高的设计方案。论文主要讨论了一种高压、350mA、低压差线性恒流型高亮度LED驱动芯片的研究与设计。设计先按照芯片需完成的功能,确定系统的结构与电路划分,然后结合“自底向上”的原理图输入设计方法对部分电路进行设计,最后根据系统设计的框架对各电路进行协调设计,并进行芯片的整体性能验证。本文的研究重点在于低压差线性恒流型高亮度LED驱动芯片的总体设计与线性恒流型驱动的效率改进,详细介绍了芯片中带隙基准与稳压输出、误差放大器、过热保护等子电路的设计过程,并给出了相应的仿真结果和分析。
在前面研究的基础上,采用Jazz 0.5μm BCD制造工艺完成了一款低压差线性恒流型高亮度LED驱动芯片的前端与后端设计。芯片后仿真结果表明,芯片可工作于汽车电子级宽输入电源电压范围(+6.3V~+32V)与宽温度范围(-40℃~+125℃);具有过热保护、过流保护、PWM亮度调节使能控制、204mV低电流检测基准等功能;在+12V电源电压下输出电流精度在±2.86%以内,实现典型值为0.5V的低压差设计;另外,对线性恒流型高亮度LED驱动的优化设计有效地提高了芯片效率。后仿真结果表明芯片的设计指标达到既定的要求。
High Brightness LED as the most promising light source has many advantages, such as high luminous efficiency, high luminous intensity, economical and safety for environment, long life period etc. It is widely used in automotive illumination, display, the flash on cell-phone camera, back lighting of panel and other illuminating applications. The HB LED driver is indispensable, and become the star of power management research. Providing constant current is the major task. For its briefness, low noise and EMI, fast transient response, mini bulk and inexpensive, linear current regulator is well suited for illuminating fields using storage battery as power supply, such as automotive illumination. In this thesis, the research and design of a high voltage, 350 mA, LDO linear current regulative HB LED driver is demonstrated. According to the functions the IC should have, the structure and functional blocks of the system were determined, then the direct schematic design of some subcircuits had also been conducted in reference to other function-like circuits, using the“Bottom-to-up”methodology. Then, the whole chip simulation and verification were conducted to examine the matching between the design and the requirements of specification. The thesis put emphasis on the whole design of the chip and improvement on efficiency of the linear current regulator, especially on the design of some critical blocks, such as reference and voltage regulator block, error amplifier block and thermal protect block.
On the basis of above research, a LDO linear current regulative HB LED driver is designed and fabricated in Jazz 0.5μm BCD process. Simulation results show that the chip can achieve±2.86% output current accuracy and 0.5V low-dropout voltage, and it features the functions of over temperature protection, over current limiting, PWM dimming at output current as well as low 204 mV current-sense reference. Besides, optimization design for the LED driver improved the efficiency effectively. The post simulation has proved that the circuit works very well and every electrical characteristic meets the specification of the data sheet which proves a successful design.
引文
[1]王海鸥.认识照明LED.中国照明电器, 2004, 2: 1-3
[2] Pedro Pachuca, Rod Borras.基于微控制器的LED驱动器拓扑、权衡和局限. http://www.freescale.com.cn/tech_ariticles/2006/0216.asp
[3]李忠辉,丁晓民.高亮度InGaN基白光LED特性研究.红外与毫米波学报, 2002, 21(5): 390-392
[4] Nadarajah Narendran, Gu Yimin. Life of LED-Based White Light Sources. IEEE OSA Journal of Display Technology, 2005, 1(1): 167-171
[5]李薇.中外半导体照明市场分析.照明工程师社区. http://www.5izm.net/article. php/6504
[6]赛迪顾问.半导体照明助推高亮度LED管芯市场发展.照明工程师社区. http://www.5izm.net/article.php/1170
[7] Maxim. 1.2A White LED Regulating Charge Pump for Camera Flashes and Movie Lights. www.maxim-ic.com.cn/quick_view2.cfm/qv_pk/4510
[8] Maxim. 1x/1.5x/2x White LED Charge Pump with Two LDOs in 4mm x 4mm Thin QFN. www.maxim-ic.com.cn/quick_view2.cfm/qv_pk/4723
[9] Maxim. High-Voltage, 350mA, Adjustable Linear High-Brightness LED (HB LED) Driver. www.maxim-ic.com.cn/max16800
[10] Linear Technology. Step-Down 1A LED Driver. www.linear.com.cn/pc/product Detail.do?navId=H0,C1,C1003,C1094,P11079
[11] Linear Technology. Dual 1.3A White LED Step-Up Converters with Wide Dimming. www.linear.com.cn/pc/productDetail.do?navId=H0,C1,C1003,C1042,C1031,C1061, P10673
[12] Sipex. Constant Current LED Driver. www.sipex.com/Files/DataSheets/SP7618.pdf
[13] Sipex. 400mA Buck/Boost Charge Pump LED Driver. www.sipex.com/Files/Data Sheets/SP6686.pdf
[14] National Semiconductor. 0.5A Constant Current Buck Regulator for Driving High Power LEDs. www.national.com/pf/LM/LM3402.htm
[15] Frank Kolanko.技术教程:面向汽车应用的线性调整器与开关调整器的比较. http://www.autoelectronics.eetchina.com/ART_8800425389_2100001_01304ede200607.HTM
[16]厦门联创微电子股份有限公司. XLT604高亮度LED驱动芯片. www.linktron. com.cn/produces/LED/XLT604.pdf
[17]侯建国,陈鸣,陈建.高亮度白光发光二极管发光特性的研究.光源与照明, 2006, 2: 12-14
[18]张明.新型Led驱动器的设计理念.电子系统设计. http://www.ed-china.com/ART _8800016861_400011_500009_OT_98432ED4.HTM
[19] Michael. Day. LED Driver Considerations. http://focus.ti.com/lit/an/slyt084/slyt084 .pdf
[20] Michael Day.白光LED驱动器的选择策略和设计实例.电子工程专辑. http://www.eetchina.com/ART_8800341697_617681,617690.HTM
[21]刘佐濂.驱动白光LED的升压式变换器XC9103.广州大学学报(自然科学版), 2006, 5(1): 20-23
[22] Volk K R.白光LED的恒流驱动.电子产品世界, 2003, 9: 57-58
[23]曹会宾.用低压差线性稳压器优化开关电源设计.电子工程专辑. http://www.eetchina.com/ART_8800382618_628868_0c635472200511.HTM
[24] Mitchell Lee, Hua Bai, Jeff Witt.汽车电子保护电路设计.国际电子商情. http://www.esmchina.com/ART_8800071178_617671_4908807d200610.HTM
[25] Phillip E Allen, Douglas R Holberg. CMOS模拟集成电路设计(第二版).冯军,李智群(译).北京:电子工业出版社, 2005: 143-150
[26] Razavi B.模拟CMOS集成电路设计.陈贵灿,程军,张瑞智等(译).西安:西安交通大学出版社, 2000: 312-314
[27] W. Timothy Holman. A New Temperature Compensation Technique for Bandgap Voltage References. Circuits and Systems, 1996. ISCAS '96, 'Connecting the World', 1996 IEEE International Symposium on Volume 1, 12-15 May 1996: 385-388
[28] Bang S. Lee. Understanding the Terms and Definitions of LDO Voltage. http://focus. ti.com/lit/an/slva079/slva079.pdf
[29] The Engineering Staff of Texas Instruments Semiconductor Group. Technical Review of Low Dropout Voltage Regulator Operation And Performance. http://focu s.ti.com/lit/an/slva072/slva072.pdf
[30] Jeff Falin. ESR, Stability, and the LDO Regulator. http://focus.ti.com/lit/an/slva115/ slva115.pdf
[31] Brokaw, A.P. A simple three-terminal IC bandgap reference. Solid-State Circuits. IEEE Journal of Solid State Circuit, Volume 9, Issue 6, Dec 1974: 388-393
[32] Paul R. Gray, Paul H. Hurst, Analysis and Design of Analog Integrated Circuits. Fourth Edition, John Wiley & Sons, Inc. 2001: 246
[33] Rudy J, van de Plassche. A Wide-Band Monolithic Instrumentation Amplifier. IEEE Journal of Solid State Circuits, 1975, 11(6): 424-431
[34] Gert van der Horn, Johan H. Huijsing. Extension of the Common-Mode Range of Bipolar Input Stages beyond the Supply Rails os Operational Amplifiers and Comparators. IEEE Journal of Solid State Circuits, 1993, 28(7): 750-757
[35]康华光,陈大钦等.电子技术基础模拟部分(第四版).北京:高等教育出版社, 1999: 229
[36]张炽昌,邵丙铣.一种热关断电路的设计.微电子学, 1999, 29(4): 302-304
[37]游轶雄,刘正,徐永晋等.一种CMOS过热保护电路.上海大学学报(自然科学版), 2002, 8(4): 293-296
[38]蒋湘. FTTH光模块集成电路设计与验证.华中科技大学电子科学与技术系: [博士学位论文].武汉:华中科技大学图书馆, 2006
[39] Christopher Saint, Judy Saint.集成电路掩模设计——基础版图技术.周润德,金申美(译).北京:清华大学出版社, 2006: 15-35
[40]王颖. MOS集成电路ESD保护技术研究.微电子技术, 2002, 30(1): 24-28
[41] Montiel Nelson J. A., Armas V. de, Sarmiento R., et al. A Compact Layout Technique for Reducing Switching Current Effects in High Speed Circuits. IEEE 2001 2nd International Symposium on Quality Electronic Design, 2001: 26-28
[42] Zhang Shuo, Dai Wayne. TEG: a New Post-Layout Optimization Method. IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, 2003, 22(4): 446-456
[43] OSRAM Opto Semiconductors. Golden DRAGON Simulation Model. http://catalog. osram-os.com/catalogue/catalogue.do?act=showBookmark&favOid=000000000002529300090023
[2] Pedro Pachuca, Rod Borras.基于微控制器的LED驱动器拓扑、权衡和局限. http://www.freescale.com.cn/tech_ariticles/2006/0216.asp
[3]李忠辉,丁晓民.高亮度InGaN基白光LED特性研究.红外与毫米波学报, 2002, 21(5): 390-392
[4] Nadarajah Narendran, Gu Yimin. Life of LED-Based White Light Sources. IEEE OSA Journal of Display Technology, 2005, 1(1): 167-171
[5]李薇.中外半导体照明市场分析.照明工程师社区. http://www.5izm.net/article. php/6504
[6]赛迪顾问.半导体照明助推高亮度LED管芯市场发展.照明工程师社区. http://www.5izm.net/article.php/1170
[7] Maxim. 1.2A White LED Regulating Charge Pump for Camera Flashes and Movie Lights. www.maxim-ic.com.cn/quick_view2.cfm/qv_pk/4510
[8] Maxim. 1x/1.5x/2x White LED Charge Pump with Two LDOs in 4mm x 4mm Thin QFN. www.maxim-ic.com.cn/quick_view2.cfm/qv_pk/4723
[9] Maxim. High-Voltage, 350mA, Adjustable Linear High-Brightness LED (HB LED) Driver. www.maxim-ic.com.cn/max16800
[10] Linear Technology. Step-Down 1A LED Driver. www.linear.com.cn/pc/product Detail.do?navId=H0,C1,C1003,C1094,P11079
[11] Linear Technology. Dual 1.3A White LED Step-Up Converters with Wide Dimming. www.linear.com.cn/pc/productDetail.do?navId=H0,C1,C1003,C1042,C1031,C1061, P10673
[12] Sipex. Constant Current LED Driver. www.sipex.com/Files/DataSheets/SP7618.pdf
[13] Sipex. 400mA Buck/Boost Charge Pump LED Driver. www.sipex.com/Files/Data Sheets/SP6686.pdf
[14] National Semiconductor. 0.5A Constant Current Buck Regulator for Driving High Power LEDs. www.national.com/pf/LM/LM3402.htm
[15] Frank Kolanko.技术教程:面向汽车应用的线性调整器与开关调整器的比较. http://www.autoelectronics.eetchina.com/ART_8800425389_2100001_01304ede200607.HTM
[16]厦门联创微电子股份有限公司. XLT604高亮度LED驱动芯片. www.linktron. com.cn/produces/LED/XLT604.pdf
[17]侯建国,陈鸣,陈建.高亮度白光发光二极管发光特性的研究.光源与照明, 2006, 2: 12-14
[18]张明.新型Led驱动器的设计理念.电子系统设计. http://www.ed-china.com/ART _8800016861_400011_500009_OT_98432ED4.HTM
[19] Michael. Day. LED Driver Considerations. http://focus.ti.com/lit/an/slyt084/slyt084 .pdf
[20] Michael Day.白光LED驱动器的选择策略和设计实例.电子工程专辑. http://www.eetchina.com/ART_8800341697_617681,617690.HTM
[21]刘佐濂.驱动白光LED的升压式变换器XC9103.广州大学学报(自然科学版), 2006, 5(1): 20-23
[22] Volk K R.白光LED的恒流驱动.电子产品世界, 2003, 9: 57-58
[23]曹会宾.用低压差线性稳压器优化开关电源设计.电子工程专辑. http://www.eetchina.com/ART_8800382618_628868_0c635472200511.HTM
[24] Mitchell Lee, Hua Bai, Jeff Witt.汽车电子保护电路设计.国际电子商情. http://www.esmchina.com/ART_8800071178_617671_4908807d200610.HTM
[25] Phillip E Allen, Douglas R Holberg. CMOS模拟集成电路设计(第二版).冯军,李智群(译).北京:电子工业出版社, 2005: 143-150
[26] Razavi B.模拟CMOS集成电路设计.陈贵灿,程军,张瑞智等(译).西安:西安交通大学出版社, 2000: 312-314
[27] W. Timothy Holman. A New Temperature Compensation Technique for Bandgap Voltage References. Circuits and Systems, 1996. ISCAS '96, 'Connecting the World', 1996 IEEE International Symposium on Volume 1, 12-15 May 1996: 385-388
[28] Bang S. Lee. Understanding the Terms and Definitions of LDO Voltage. http://focus. ti.com/lit/an/slva079/slva079.pdf
[29] The Engineering Staff of Texas Instruments Semiconductor Group. Technical Review of Low Dropout Voltage Regulator Operation And Performance. http://focu s.ti.com/lit/an/slva072/slva072.pdf
[30] Jeff Falin. ESR, Stability, and the LDO Regulator. http://focus.ti.com/lit/an/slva115/ slva115.pdf
[31] Brokaw, A.P. A simple three-terminal IC bandgap reference. Solid-State Circuits. IEEE Journal of Solid State Circuit, Volume 9, Issue 6, Dec 1974: 388-393
[32] Paul R. Gray, Paul H. Hurst, Analysis and Design of Analog Integrated Circuits. Fourth Edition, John Wiley & Sons, Inc. 2001: 246
[33] Rudy J, van de Plassche. A Wide-Band Monolithic Instrumentation Amplifier. IEEE Journal of Solid State Circuits, 1975, 11(6): 424-431
[34] Gert van der Horn, Johan H. Huijsing. Extension of the Common-Mode Range of Bipolar Input Stages beyond the Supply Rails os Operational Amplifiers and Comparators. IEEE Journal of Solid State Circuits, 1993, 28(7): 750-757
[35]康华光,陈大钦等.电子技术基础模拟部分(第四版).北京:高等教育出版社, 1999: 229
[36]张炽昌,邵丙铣.一种热关断电路的设计.微电子学, 1999, 29(4): 302-304
[37]游轶雄,刘正,徐永晋等.一种CMOS过热保护电路.上海大学学报(自然科学版), 2002, 8(4): 293-296
[38]蒋湘. FTTH光模块集成电路设计与验证.华中科技大学电子科学与技术系: [博士学位论文].武汉:华中科技大学图书馆, 2006
[39] Christopher Saint, Judy Saint.集成电路掩模设计——基础版图技术.周润德,金申美(译).北京:清华大学出版社, 2006: 15-35
[40]王颖. MOS集成电路ESD保护技术研究.微电子技术, 2002, 30(1): 24-28
[41] Montiel Nelson J. A., Armas V. de, Sarmiento R., et al. A Compact Layout Technique for Reducing Switching Current Effects in High Speed Circuits. IEEE 2001 2nd International Symposium on Quality Electronic Design, 2001: 26-28
[42] Zhang Shuo, Dai Wayne. TEG: a New Post-Layout Optimization Method. IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, 2003, 22(4): 446-456
[43] OSRAM Opto Semiconductors. Golden DRAGON Simulation Model. http://catalog. osram-os.com/catalogue/catalogue.do?act=showBookmark&favOid=000000000002529300090023