单片开关电源的研究

【作者】 杨仕伟；

【导师】 杨健；

【作者基本信息】 贵州大学 ， 微电子学与固体电子学， 2009， 硕士

【摘要】 随着电子技术的发展,电子系统的应用领域越来越广泛,电子设备的种类也越来越多,对电源的要求更加灵活多样。电子设备的小型化和低成本化使电源以轻、薄、小和高效率为发展方向。单片开关电源是开关电源专用集成电路,他将脉宽调制电路与高压MOSFET开关管及驱动电路等集成在一起,具备完善的保护功能。使用该芯片设计的小功率开关电源,可大大减少外围电路,降低成本,提高可靠性。现在一般应用的串联调整稳压电源,是连续控制的线性稳压电源,这种传统的串联稳压器,调整管总是工作在放大区,流过的电流是连续的,这种稳压器的缺点是承受过载和短路的能力差、效率低。本文介绍了开关电源的基本构成以及开关电源的核心部分,研究了一种新型的PWM脉冲宽度调制开关电源电路,它具有电路较简单,组成元件较少,功耗低,转换损失低,应用广泛等特点。文中,作者首先介绍了PWM的工作方式,然后按照超大规模集成电路设计方法,设计了电路的整体框架和各部分子模块,对各子模块进行了功能仿真。分析了单片开关电源的特性和工作原理,对系统中振荡器电路、基准电压源电路、保护电路、PWM比较器电路、误差放大器电路、SCHMITT触发器电路、八分频电路等几个部分进行了详细的分析,并按照指标要求,进行了实际参数值计算、器件的选取与电路设计;最后,给出了该电源输出实验波形及整体性能分析;实验证明:该开关稳压电源效率高、纹波小、输出电压稳定,性能优良,此电源具有低成本、高效率、小尺寸、全密封式的特点,适合于仪器仪表的控制用电。更多还原

【Abstract】 Nowadays, electronic systems become more and more popular with the development of electronic science and technology. As the most important part of electronic systems, power supply is becoming more and more versatile. And it has been developing towards the trend of light, more flexible, and more efficient. Single-chip switching power supply are produced especially for switching power supply, which integrate PWM and high voltage MOSFET together , and have perfect protection function. Designing low power switching power supply with such integrated circuits can decrease parts count and cost, increase reliability.Nowadays the applied series adjustable regulator is linear regulator of continuous control. The traditional series regulator, it s adjustable transistor always working at amplifier area, the electric current is continuous, the disadvantages of regulator are low efficient and capability in overload. The paper introduces basic structure of switching power supply and type of power converter. In this paper, a new PWM monolithic switched power supply circuit is researched. The author firstly introduces the basic theories about PWM then under the guidance of methodology of integrated circuits design the author has designed the total circuit. The author simulates functions of every module. Firstly, the principle and characteristics of this Single-chip switching power supply are analyzed. Second, the external circuits of system include several parts, these are an oscillator circuit, Datum potential source, protection circuit, PWM comparator electric circuit, error repeater circuit, SCHMITT trigger circuit, eight frequency dividing circuits. According to the design requirements , the detailed analysis of the several parts is presented, calculation of the values of the parameters and selection of the components are provided. At last, output voltage wave and the analysis of the whole electrical character are given. The test result shows the power supply have high efficiency, low ripple, stability output voltage and excellent electrical characteristics, this power supply is low cost, high efficiency, small size and fully sealed, and be used as control power supply of instruments and meters.更多还原