一种采用混合调制模式的离线开关电源芯片的设计

【作者】 廖平；

【导师】 陈星弼；

【作者基本信息】 电子科技大学 ， 微电子学与固体电子学， 2009， 硕士

【摘要】 单片开关电源管理集成电路具有高集成度、高性价比、简单外围电路、优越性能指标等优点,能构成高效率无工频变压器的隔离式开关电源,目前己成为国际上开发中、小功率开关电源、精密开关电源、专用开关电源以及开关电源模块的优选集成电路,使得开关电源正朝着短、小、轻、薄的方向发展。本文采用CMOS工艺,参考了PI公司的TNY芯片的电性参数,正向设计了一种采用了混合调制模式的离线式开关电源芯片。芯片内部集成了耐压700V的功率管,最大输出功率约为15W。开关的工作模式由内部集成的极限电流状态机和自动重启电路控制,该状态机能够感应外部负载的轻重,并将其划分为不同的状态。在轻载时,输出功率较低,重载时输出功率变高,使开关在不同情形下都能发挥最大的效率。论文首先介绍了开关电源的基本原理,以及PWM、PFM等调制模式。然后,详细介绍了反激变换器和芯片整体电路框架图。随后的第三章设计了芯片内部的状态机、自动重启电路和电容选择电路等数字电路,第四章阐述了基准源、jitter振荡器和过温、欠压等保护电路的工作原理和仿真结果。最后,论文介绍了芯片的版图设计以及流片的测试结果和分析。更多还原

【Abstract】 Single-chip switching power supply management IC has many virtues such as high integration level, most cost effective, lowest component count switcher solution, and high performance. Making use of it can form high efficiency insulated switching power supply without using utility power transformer. The switching power IC is selected firstly in the design of high power switching power supply, precision switching power supply, application specific switching power supply and so on in the world, which has been making switching power supply short, small, light and thin.Based on CMOS technology, adopting hybrid modulation, an off-line switcher chip which has the same electronic parameters as TNYs is developed. A power MOSFET with breakdown voltage exceeding 700V is integrated on this chip, and the maximum output power is about 15W. The operational mode is controlled by the current limit state machine and auto-restart circuit, both of which are integrated in this chip. The current limit state machine can feel the weight of the load and defines it as different states. The output power is small in light state and becomes larger in heavier state, which makes the switcher have the best efficiency.The basic theory of SMPS, PWM and PFM are given first. The fly back converter and the function block diagram of the chip are introduced later. And then Chapter 3 explains the working of digital circuits such as state machine, auto-restart counter, bypass capacitor selector and so on. The principle and simulation results of voltage reference, jitter oscillator, protection circuits are introduced in Chapter 4. Finally, this paper introduces the chip’s layout design, and the testing result and analysis are given.更多还原