51单片机脉宽调制控制器外文文献及翻译.docVIP

51单片机脉宽调制控制器外文文献及翻译 51单片机脉宽调制控制器外文文献及翻译Design of PWM Controller in a MCS-51 Compatible MCU Yue-Li Hu, Wei WangMicroelectronic Research Development Center,Key Laboratory of Advanced Display and System Applications (Shanghai University), Ministry of Education Campus P.O.B.221, 149 Yanchang Rd, Shanghai 200072, ChinaE-mail: lwfree@AbstractThis paper presents a design of Pulse-Width Modulated(PWM) controller module in a MCU based on MCS-51structure. The design can generate 2-channel programmable periodic PWM signals. These output PWM signals from MCU can be used for a variety of applications including motor control. The function of the design allows users to select independent or complementary inversion timing relationships between 2 PWM wave forms. The latter mode selection also includes optional dead time function to support driving H-bridges and inverters. Therefore, users can controlthe output PWM signals through setting the duty-cycle registers. After the successful simulation at the front end, practical experiments made on a NIOS development board verify the design.1. IntroductionPWM technology is a kind of voltage regulation method by controlling the switch frequency of DC power with fixed voltage to modify the two-end voltage of load. This technology can be used for a variety of applications including motor control, temperature control and pressure control and so on. In the motor control system shown as Fig. 1, through adjusting the duty cycle of power switch, the speed of motor can be controlled. As shown in Fig. 2, under the control of PWM signal, the average of voltage that controls the speed of motor changes with Duty-cycle ( D = t1/T in this Figure ),thus the motor speed can be increased when motor power turn on, decreased when power turn off.Fig.1 PWM control block diagramFig.2: The Relationship between Voltage of Armature and Duty-cycleTherefore, the motor speed can be controlled with regularly adjusting the time of turn-on and turn-off. The