【作者】 刘伟；

【导师】 余宁梅；

【作者基本信息】 西安理工大学 ， 微电子学与固体电子学， 2008， 硕士

【摘要】 随着电力电子技术的发展,电力电子设备与人们的工作生活关系日益密切,而任何电子设备都离不开可靠的电源。电源分为线性电源和开关电源,其中普遍采用的是开关电源。开关电源具有低功耗、高效率以及电路结构简单的特点,因此广泛应用于计算机、电子设备、仪器仪表、通信设备及家用电器产品中。开关电源正在向轻、薄、小以及高效率方向发展。本文设计了一种新型低功耗电流模式反激式AC/DC开关电源控制芯片,重点对该芯片的运算放大器及相关保护电路进行了研究和仿真。首先,对开关电源中经常会用到的运算放大器进行深入研究分析,提出了一种新型轨对轨运算放大器的设计方案。该结构采用新加坡charter公司0.35um工艺进行版图绘制及后仿真验证并进行流片。该运放利用浮栅结构和负反馈电路来保持共模电平的恒定,并采用折叠式共源共栅电路加辅助运放的结构作为中间级来提高电路增益。这种新型的电路结构增大了输入级的范围,减小了输入对管跨导的波动,提高了整体电路结构的增益、带宽、压摆率,并且很大程度的节省了芯片面积。电源为-1.5V—+1.5V时,当电路输入范围为-5V—+5V,输入对管的跨导变化为3%;当共模电平变化在-2.5V—+2.5V之间时输入对管的跨导变化为0.7%;电路的增益为68dB,带宽为4.73MHZ,压摆率SR为SR+=33.6V/US、SR-=35V/US。其次,完成双极型保护电路的设计和仿真。具体模块包括:OSC振荡器、限流保护(上限电流比较器、上限电流触发器)、1.8V比较、PWM比较器、过压保护、斜坡电流驱动、电压调节器、斜坡补偿、电压基准。最后,完成CMOS开关电源控制电路中的保护模块的设计和仿真,具体模块包括:温度保护、数字逻辑电路(基本RS触发器、D触发器、八分频)、比较器(普通两级开环比较器)、限流保护、过压保护、LDO、软启动。更多还原

【Abstract】 With the development of electric power and electron,the relationship between the equipment of electric power and electron and human-being is getting more and more consanguineous,and it is well known that any equipment can work without power supply. Power supply can be divided into two kinds,which are linearity power supply and switch power supply.Switch power supply is applied at large nowadays because of its low consumption,high efficiency and simple circuit configuration.So it is widely used in computer,electronic equipment,communications equipment.Switch power supply is becoming light,small,thin and high efficiency.A new type of current-mode,low consumption single-chip controller is designed for the fly-back switching power supply of AC/DC.The keystone is the research and simulation of protective circuit.Firstly,study the operation amplifier which is widely used in switch power supply carefully.Design for a new scheme for rail to rail operational amplifiers.The configuration is adopted 0.35um process of charter to draw layout,do post simulation and tape out.The common level of input stage is kept constant by floating gate transistors and feedback circuitry. Also,as the middle stage,a folded cascade added by assistant operation amplifiers is employed to advance the performance.The new configuration has a wide input range,little fluctuation of gm,high gain,large bandwidth and SR.What’s more,it takes up less area. When the power supply is -1.5V—+1.5V and the input voltage range is -5V—+5V.,the gm variation of input differential transistors is 3%;when the input common voltage range is -2.5V—+2.5V,the gm variation of input differential transistors is 0.7%.The gain is 68dB. Bandwidth is 4.73MHZ.SR+ is 33.6V/US,SR- is 35V/US。Secondly,design and simulate bipolar protective circuit.The detailed modules of bipolar protective circuit are Oscillation,Limit current protection,1.8V compare,PWM comparison, Over voltage protection,Slope current drive,Voltage adjuster,Slope compensation,Voltage reference.Lastly,design and simulate CMOS protective circuit.The detailed modules of CMOS protective circuit are over-temperature protection,digital logic circuit,comparison,Limit current protection,over-voltage protection,LDO,soft-startup.更多还原