摘要
系统采用AVR单片机作为降压型开关电源的控制核心,其工作原理为:利用AVR单片机片上集成A/D,不断检测电源的输出电压,根据电源输出电压与设定值之差,输出脉冲调制信号,直接控制功率开关脉宽的大小。电路主要部分包括整流滤波模块、开关电源控制模块、过流保护模块、LCD液晶显示模块等。根据实际要求,合理选用MOSFET功率器件,自制电感并配置系列参数。测试结果表明,小功率开关电源的电压调整率为0.15%;负载调整率为-0.34%;纹波电压峰峰值小于0.1V;满载效率达到91.3%以上。
The operating principle of buck switch mode power supply based on AVR MCU is introduced in the paper. The microcontroller system based on Atmega128 estimates the variance between set value and output voltage by means of integrated A/D converter in the system, then produces the signal of pulse modulation, and controls directly the MOSFET in the circuit. The system of low-power numerical control switching power supply circuit modules mainly includes commutating and filter circuit, the control circuit, the current foldback circuit and the LCD display circuit. The module number of MOSFET and parameters of inductance are selected properly in the system. The kinds of index of buck switch mode power supply： voltage-regulating rate 0. 15%, load-regulating rate --0. 34%, voltage ripple range≤ 0. 1 V, full-load efficiency≥91.3 %.
出处
《电子测量技术》
2009年第2期32-35,42,共5页
Electronic Measurement Technology
关键词
电压型脉冲宽度调制
转换效率
储能电感
过流保护
voltage mode PWM
transfer efficiency
energy storage induction
overeurrent protect
