【作者】 肖华；

【导师】 刘舜奎；

【作者基本信息】 厦门大学 ， 仪器仪表专业， 2009， 硕士

【摘要】 随着工艺的发展及许多SOC产品及便携式电子产品的工作电压不断下降,省电观念越来越引人注目,对提供电源的芯片要求越来越高。针对供电电源日趋低压化,以及节能环保意识成为各个国家及众多消费者的共识,低电源电压下能工作且具有低功耗成为线性稳压器的发展趋势。本文提出了一种输出电压1.5V,输入电压可以低至1.7V的情况下稳定工作并能提供300mA电流的低压差线性稳压器电路,整个线性稳压器电路的静态电流低于40uA。与传统的低压差线性稳压器相比,本文设计的低压差线性稳压器电路系统提出了利用有源前馈米勒补偿(AFFC)与共源共栅米勒补偿相结合的新颖动态米勒补偿结构,这种补偿结构下的电路系统具有恒定的带宽(100KHz以上),大大提高了系统的瞬态响应性能。同时由于输出电压调节器模块采用了三级放大器结构,整个电路系统的增益提高了30dB左右,使得电压调节器系统具有极高的线性调整能力和负载调整能力。本文还设计了可以工作在低至1.5V电源电压下的具有75dB的电源抑制比的自偏置电流带隙基准源电路。该带隙基准源在-20℃到120℃范围内具有12ppm/℃的温度特性。同时该带隙基准源带有快速启动电路,启动时间小于20us。还有本文还设计了过流保护电路和带有迟滞特性的过温保护电路。本文设计的电路都利用Hspice软件进行了详细的仿真验证。更多还原

【Abstract】 With the developments of electronics and telecommunication,portable electronical products become more and more popular.The developments of power management technologies and applications are rapidly promoted.A high-accuracy,micro power and low-dropout(LDO)voltage regulator is presented in this paper.A novel compensation structure that using the Active-Feedback Frequency Compensation (AFFC)scheme and the Cascode Miller Compensation scheme is presented,which to solve the stability problem of low dropout voltage regulators.Compared with the conventional methods,it keeps the bandwidth stable to improve the performance of transient response greatly.The new LDO effectively overcomes the stability problem,facilitates the use of a ceramic capacitor.The LDO voltage regulator’s system increases the open loop gain by 30dB by using the structure of three stage amplifiers,which makes the LDO have high line regulation and load regulation specification.The new LDO was operable at input voltage 1.7V.A novel band-gap reference structure is presented,which has the bias current of OP AMP that generated by the band-gap voltage reference self,thus having the PTAT current generator omitted,reducing the chip area and making the reference current closer to the ideal PTAT current.Simulation result show that the band-gap voltage regulator temperature coefficient is 12ppm/℃within the temperature range:-20℃～120℃,the power rejection at low frequency is 75dB,and the quiescent current of this band-gap voltage reference is about 12uA.The function of preventing temperature and current from over ranging is designed in the regulator.更多还原