【作者】 汪华；

【导师】 邹雪城；

【作者基本信息】 华中科技大学 ， 软件工程， 2007， 硕士

【摘要】 液晶显示器以其轻巧便捷、低功耗和易集成等特点成为目前信息显示技术领域的研究热点和主导技术。液晶显示器在便携设备中得到广泛应用,这也推动开关电源技术不断进步。应用领域的扩大,要求开关电源具备高效率、高可靠性和高功率密度等特点,这对开关电源芯片设计提出了新的挑战。本文在深入研究开关电源升压变换器电路相关技术的基础上,讨论了一种工作在640KHz和1.2MHz频率可选的电流型PWM升压变换器控制芯片的设计方案。首先,依据芯片的应用要求提出设计规格定义,然后,设定系统的工作原理,并结合电路设计中的关键因素给出系统结构设计,接着就芯片中部分主要功能模块进行电路结构设计,并使用Cadence Spectre给出相关的仿真验证结果。最后,在介绍芯片典型应用电路的基础上进行了全局电路仿真,验证了最初的设计方案。作为开关电源而言,高的变换效率和高的功率密度始终是最重要的设计指标。本文所介绍的电路设计采用一些简单的电路,在实现电路功能的前提下,不仅保证开关变换器在典型应用条件下获得较高的变换效率,而且也实现了业界较高的功率密度。其中频率提高是实现高功率密度的关键。本次设计基于0.5μm BCD工艺实现,系统仿真结果表明该升压变换器控制芯片具备以下优点:快速的瞬态响应能力、小的输出纹波、高的功率密度以及较为理想的变换效率(典型应用下高达90%)。更多还原

【Abstract】 LCD (Liquid Crystal Display) is the research center and magistral technologe of information display field because of its legerity, portability, low power consuming and easily integratied. With the widely utilization of LCD in portable devices, the rapid process actuates constantly the advancement of the technique of switching power supply. As the application field expanded, the demand on high efficiency, high reliability and high power density becomes the new design challenge to switching power supply IC.Based on the in-deep study of the interrelated technique of the DC-DC boost converters, a design scheme of the switching regulator of current-mode PWM boost converters operating at a alterable frequency of 640kHz or 1.2MHz is presented. According to the application demands a specification is put forward, the working principles of the converter are also explained. By consideration the key factors of the circuit design the structure of the converter is defined, then the design procedure of some primary function blocks are presented, with the simulation by Cadence Spectre. Lastly, a typical application circuit is introduced, based on which the whole chip simulation is achieved.The higher efficiency and high power density is the most important design guidelines for DC-DC switching regulators, all the time. In this thesis a pithy circuit design style is introduced, that insures the converter obtains the higher efficiency and the industry’s high power density with the circuit functions fully achieved.The design is implemented base on the 0.5μm BCD technologies, with the fully system-level simulations. The results indicate that the controller has a fast transient response with small output ripple coefficient less than 0.417%, upstanding load regulation less than 1% and quite fine efficiency up to 90% in typical application. The high power density can be achieved by using high efficiency.更多还原