摘要
在当今的消费品市场上,各种电子产品已经获得广泛的应用。随着新产品功能的日益丰富,对电源电压的种类提出更高的要求。为适应市场需求,本文分析设计一种集成降压变换器和线性调节器的多输出DC-DC变换器。它采用UMC 0.6μm BCD工艺制程,其内部集成一个线性调节器、一个降压控制器和三个外部低压降线性调节器的控制器。线性调节器为整个内部电路提供工作电压,也可提供较小的外部负载电流。该变换器具有使能关断的功能,关断状态下除内部线性调节器和基准源模块外,其他功能模块均不工作;具有软启动功能,限制电路启动期间的电感电流过冲;具有可编程启动顺序的功能,使低压降线性调节器易于控制;具有开漏计时复位输出功能,确保数字电路的正常启动。工作电压范围为4.5~28V,工作温度范围为-25~+85℃。适合于AC/DC适配器直接供电的LCD监视器和TV应用。
在论文中,作者首先阐述了DC-DC变换器的分类,并根据本文特点介绍BUCK电路和LDO电路的基本原理和关键技术,指明整体电路设计的理论依据。接着从设计要求的角度出发提出整体电路的架构设计,阐述了整体工作原理,并根据整体电路的功能要求完成子电路的设计与仿真。由于本芯片的设计是由小组成员共同完成的,作者主要负责总体电路的分析、联合仿真验证及以下四个子电路的设计:带隙基准电压源、基准电流源、复位输出电路和启动序列电路。最后,作者对整体电路的功能和典型性能参数进行仿真验证。在论文的结论部分,作者指出该电路在理论研究上的可参考性,同时也表明了该电路欲投入生产则还需要做容差分析、版图设计和后仿真等后续工作。
本文是电路设计理论和仿真实践相结合的结果。作者在电路原理分析的基础之上,运用HSPICE仿真软件对子电路模块和整体电路进行功能和性能参数的仿真验证,仿真结果均达到或优于预定指标,证实了理论分析的正确性。
In today’s consumer market, electronic devices are in great demand. With more and more functions integrated in these devices, power management integrated circuits such as DC-DC converters with higher performance are mandatory. In order to meet the requirements, a multiple-output DC-DC converter integrated with step-down converter and linear regulator controllers is designed in this thesis. It is based on UMC 0.6μm BCD process, and integrated an internal linear-regulator, one step-down converter and three low dropout linear regulators. When it is shut down, the step-down regulator and all linear regulators are turned off, but the internal linear-regulator and internal reference remains active. An internal linear regulator provides MOSFET gate drive and can be used to power small external loads. Soft-start functions to limit inrush current during startup. A programmable startup sequence enables easy control of the regulators, it also includes an open-drain timed microprocessor supervisor function to ensure proper startup of digital circuits. It operates in wide input voltage range from 4.5V to 28V. This converter can operate in the temperature rage of -25℃to 85℃. It is suitable for LCD monitor and TV applications running directly for AC/DC wall adapters.
In this thesis, basic principles and some key points of a DC-DC converter were given firstly. Then, the whole chip diagram was proposed according to the design specification and the whole chip operational principle was introduced. Based on the whole chip function requirements, sub-block design and simulation were completed. Since the chip was accomplished through the team work, the author paid particular attention to the analysis of the whole chip architecture and the design of the following sub-blocks, including bandgap voltage reference, current reference, reset and startup sequence. At last, the whole chip function simulation and typical performance characteristics simulation were presented. In the conclusion of this thesis, the research value of this circuit was pointed out, but it was suggested that corner simulation and post-layout simulation should be indispensable.
This thesis is a production of circuit principles and simulation practice. Based on the circuit principle analysis, the author simulated the sub-block circuits and the whole chip circuit by applying the EDA tool HSPICE. The simulation results indicate that the converter has achieved the design specification. Furthermore, the circuit principle analysis has been verified.
引文
[1] 李静芳.电源管理依托先进技术开创新纪元.电子技术,2005,8:3-6
[2] 2007 年:开关稳压器受宠.http://club.qingdaochina.com/view.asp?id=1058
[3] 杨斌.中国电源管理芯片市场格局难破.Electronic Business China,2006,3:5859
[4] 胡兴军.电源管理的发展趋势.电器时空,2005,11:19-20
[5] 顺应电源管理集成趋势,芯片厂商妙招不断. http://www.powersystems.eetchina.com/ART_ 8800443703_ 2400002_054a8f8e200612.HTM [6 何钰.电源管理趋势探讨.电子产品世界,2005,15:50-52
[7] Paul Greenland. A Brief Glimpse over the Power Management Horizon.电子产品世界, 2006,3:114-116
[8] 潘九堂.DC/DC 转换器市场稳定增长,产品技术持续创新.http://www.eetchina.com
[9] 全新 PWI 标准为便携设备 SoC 集成电源管理 IC 打开方便之门.http://www.eetchina.com
[10] 陈路.新型 R3 技术满足下一代便携式设备电源管理要求.http://www.eetchina.com
[11] 电源管理产品呈现五大发展趋势.http://www.ups001.com/info/021.htm
[12] 多 输 出 DC/DC 电 源 模 块 使 系 统 设 计 与 操 作 更 加 简 单 . http://www.tai-yan.com/ bbs1/htm_data/ 2/0612/439.html
[13] 张波.开关电源的优点及应用.电器开关,2007,1:39-41
[14] ALAN B, GREBENE. Bipolar and MOS analog integrated circuit design. New York: John Wiley & Sons,1984: 514-527
[15] 张占松,蔡宣三.开关电源的原理与设计.北京:电子工业出版社,2004:16-46
[16] Linear and Switching Voltage Regulator Fundamentals, National Semiconductor Application note.1999
[17] Gabriel Rincon-Mora, Phillip E. Allen. A Low-Voltage, Low Quiescent Current, Low Drop-out Regulator. IEEE,1998,33 (1):36-44.
[18] Tom Kugelstadt. Fundamental Theory of PMOS Low-Dropout Voltage Regulators, TI Company, Inc., 1999
[19] Abraham I, Pressman. Switching Power Supply Design. New York: the McGraw-Hill Companies,1998,4-10
[20] Bang S.Lee. Technical Review of Low Dropout Voltage Regulator Operation and Performance,TI Company, Inc.,1999
[21] Gabriel Alfonso, Rincon-Mora, Phillip E. Allen. Study and Design of Low Drop-Out Regulators. School of Electrical and Computer Engineering, Georgia Institute of Technology. Altanta, GA' 30332-0250.
[22] Kazimierczuk M.K, Edstrom A.J, Reatti A. Buck PWM DC-DC converter with reference-voltage-modulation feedforward control,IEEE,2001,2:537-540
[23] Lai Xinquan, Guo Jianping, Yu Weixue, etl. A Novel Digital Soft-Start Circuit for DC-DC Switching Regulator. IEEE ISCAS,2005,564-567
[24] Paul Gray. Analysis and Design of Analog Integrated Circuits. New York: John Wiley & Sons, 2001: 317-327
[25] Mahattanakul J, Pookaiyaudom S,Toumazou C. Understanding Wilson current mirror via the negative feedback approach.IEEE,2001.1:532~535
[26] Mehrmanesh S, Vahidfar.M.B, Aslanzadeh H.A,etl. A 1-volt, high PSRR, CMOS bandgap voltage reference.IEEE,2003,Vol.1,381~384
[27] Behzad Razavi. Design of Analog CMOS Integrated Circuits.清华大学出版社,2005.89-90
[28] Abraham I, Pressman.开关电源设计.王志强译.北京:电子工业出版社,2005.104-106