Advanced motor driving circuit with improved transfer efficiency based on adaptive segmented control

Abstract

An advanced motor driving circuit based on digital sampling load and adaptive segment control of power MOSFET to realize improved transfer efficiency is presented in this paper. A digital block is employed to detect the duty cycle of PWM signal which indirectly reflects the load condition. According to the duty cycle of PWM signal, a digital segment controller is employed to perform adaptively scaling the area of the power MOSFET to ensure current capacity of the power MOSFET just meets the load requirements. The power MOSFET is divided into three segments according to area ratio of 1:2:4. Area scaling step is 1/7 of the whole power MOSFET. The adaptive segmented controller contains duty cycle detector and segment controller is implemented based on FPGA. The correctness and feasibility of the proposed method are verified by experiments of a DC motor driver.