A fully integrated stepper motor driver with a novel integrated current sensing technology

Abstract

As advancements in power integrated circuit design and semiconductor technology continue, motor drivers are evolving toward smart power integrated circuit (SPIC). This paper presents the design of a high-voltage, two-phase stepper motor driver chip based on a 0.18 μm BCD process. The driver integrates several key modules, including a low-voltage power module, current sensing module, charge pump module, driver circuit module, and protection module. To improve system stability and precision, two sets of cascode current mirrors are employed to sample the H-bridge current. Test results demonstrate that the chip can reliably operate within a supply voltage range of 8 V to 40 V, achieving a maximum current output of 2 A and a continuous drive current of up to 1.6 A. Furthermore, the chip exhibits stable current steps with each stepping pulse.