大功率LED供电电源设计报告.doc

高效数控恒流电源 摘要：本文描述了高效率数控恒流电源的设计原理和实现方法，以MSP430F247单片机为主控制器，通过键盘来设置直流电源的输出电流，设置步进等级为1mA，并可由液晶显示器显示实际输出电流值和负载功率。本系统采用DC/DC变换器芯片TPS5430,其输出经功率MOS管扩流。单片机程控输出数字信号，经过D/A转换器（TLV5618）输出模拟量，再经过运算放大器隔离放大，与精密采样电阻采集电压放大后进行比较，控制DC/DC变换器的反馈端，实现对输出电流的控制。输出电流经过电流/电压转变后，通过A/D转换芯片，实时把模拟量转化为数据量，再经单片机分析处理， 通过数据形式的反馈环节，使电流更加稳定，这样构成稳定的压控电流源。实际测试结果表明，本系统输出电流稳定，不随负载和环境温度变化，并具有很高的精度，输出电流误差范围±5mA，输出电流可在20mA~2000mA范围内任意设定，输出效率可达90%以上，因而可实际应用于需要高稳定度高效率恒流源的领域。 关键词：MSP430F247单片机 DC/DC变换器 高效恒流源 Abstract This paper describes the design of high-power LED power supply principle and method to MSP430F247 microcontroller-based controller, DC power through the keyboard to set the output current, set the step level as 1mA, and the actual output current value and load power can be displayed by the LCD . This system uses DC / DC converter chip TPS5430, the output power MOS tube can expansion the current . Single Chip Programmable output digital signal, through D / A converter (TLV5618) output analog, through the operational amplifier isolation amplifier, and precision voltage sampling resistor collection enlarged compared to control DC / DC converters feedback side, to achieve the output current control. Output current through the current / voltage changes, the adoption of A / D converter chip, real-time into the analog data, and then analyzed by microcomputer processing, the feedback through the form of data links, so that current is more stable, it constitutes a stable voltage-controlled current source. Actual test results show that the system output current stability, with the load and ambient temperature changes and high Jing Du, output current error of ± 5mA, output current at 20mA ~ 2000mA Fan Wei can be arbitrarily set within, output efficiency up to 90 %, and thus the actual applications requiring high stability and high efficiency constant current field. Key words: MSP430F247 MCU DC / DC converter efficiency constant current source  目录 一：方案设计与论证 总体设计方案与比较： 方案一：从高效功率MOS管的输出特性曲线可得，当漏极和源极电压一定时，控