Design Of Two-phase Hybrid Stepping Motor Subdivision Driver IC Based On PWM

Stepping motors are widely used in automatic control field with tens of years' development. The performances of stepping motor are related closely with its driver, consequently, the study on driver of stepping motor gets more and more attention. As for the drive technique of stepping motor, subdivision drive behaves better in controlling, at the same time, integrated subdivision driver of stepping motor makes drive circuit simpler in structure, higher in security and more convenient in controlling as well as the subdivision drive is realized with excellent performance. The thesis expatiates the principle of stepping motor subdivision drive and schemes out a two-phase hybrid stepping motor subdivision driver IC based on PWM. The thesis presents the subdivision drive method by analyzing the mathematics models of two-phase hybrid stepping motor. Using subdivision drive method in the system can markedly decrease low frequency vibration of the motor and enhance motor's accuracy. Based on the principle analysis of subdivision drive of two-phase hybrid stepping motor, uses the simulant sinusoid ladder voltage that produced with 3-bit nonlinear DAC as the reference current of winding of stepping motor, makes the current of winding of stepping motor to vary also as sinusoid by controlling the on or off time of driver with PWM, achieves the constant-torque 8 subdivision drive of stepping motor. The design of this IC was completed in accordance with the design flow of ASIC. The thesis expatiates the module circuit of the IC and presents the simulation results. The feasibility and validity of the design method and principle analysis were proved by the simulation results with spectre offered by EDA tools, the subdivision driver IC of stepping motor based on PWM in the thesis can realize the target. Based on the circuit design, the thesis completed the layout of IC and confirmed its validity.