基于AT89C2051的PWM式D/A转换技术

The PWM's D/A Technique Based on AT89C2051

介绍一种新颖的PWM控制方案,该PWM控制方案采用了性价比极高的单片微控制器AT89C2051,通过软件产生PWM控制信号:利用定时器T0中断服务子程序和外部中断0服务子程序获得PWM波形的载波值和控制量,最后在主程序中实现PWM波形.同时设计了硬件电路把其转换成PWM式模拟信号以实现D/A转换,并在抗干扰方面做了一定的工作.该方案具有体积小、成本低、应用灵活等特点.并成功地应用于温度控制系统中.

A new type of PWM controller is introduced in this paper. This PWM controller bases on AT89C2051 single -chip microcontroller and produces PWM signal by software：by timer TO ISR（ interrupt service routine ） and external 0 ISR to get carrier wave value and manipulative quantum,then realize PWM wave in main program. Simultaneously,designing the hardware circuit to convert PWM signal to analog signal to realize D/A conversion. This design has the advantages of small volume, low cost and flexibility to apply and applies successfully to the control system for temperature.