基于TOP226Y的DVD开关电源的的设计.doc

基于TOP226Y的DVD开关电源的设计 摘 要 开关电源具有功耗小、效率高、稳压范围宽、体积小、重量轻等突出的优点，在通信设备、数控装置、仪器仪表、影音设备、家用电器等电子电路中得到了广泛应用。开关电源是利用现代电力电子技术，控制开关晶体管开通和关断的时间比率，维持稳定输出电压的一种电源，开关电源一般由脉冲宽度调制（PWM）控制IC和开关器件（MOSFET、BJT等）构成。 开关电源自20世纪70年代开始应用以来，涌现出许多功能完备的集成控制电路，使开关电源电路日益简化，工作频率不断提高，效率大大提高，并为电源小型化提供了广阔的前景。三端离线式脉宽调制单片开关集成电路TOP(Threeterminaloffline)将PWM控制器与功率开关MOSFET合二为一封装在一起，已成为开关电源IC发展的主流。采用TOP开关集成电路设计开关电源，可使电路大为简化，体积进一步缩小，成本也明显降低。 TOP226Y设计出通过整流、反馈、滤波、稳压等电路来实现自动稳压功能的单端反激式DVD开关电源。 关键词：开关电源 脉冲调制 TOP226Y 稳压 DVD Based on TOP226Y DVD switch power design ABSTRACT Switching power supply has little power consumption, high efficiency, wide range of voltage, small volume, light weight, outstanding qualities, in communication equipment, numerical control equipment, instruments and meters, audio-visual equipment, home appliances and other electronic circuit to a wide range of applications. Switching power supply is to use modern power electronic technology, control switch open and shut off the transistor time ratio, maintain the stable output voltage of a power supply, switching power supply general by pulse width modulation (PWM) control IC and switching device (MOSFET, BJT) constitutes. Switch power source the 1970 s since application, emerging out many function complete integrated control circuit, switch power supply circuit is simplified, continuously improve the working frequency, efficiency greatly, and increase the power miniaturization for provide a broad prospect. The three off-line pulse width modulation monolithic integrated circuit switch TOP (Threeterminaloffline) will PWM controller and power switch MOSFET 2 for one package together, has become the mainstream of switching power supply IC development. The TOP switch integrated circuit design switching power supply, can make the circuit is simpler, the volume is further narrowing, costs are significantly. This paper introduces the development of switch power supply, characteristics, classification, the TOP226Y design through the rectifier, fee