Thedesign Of A Low-voltage Brushless DC Vibration Motor Driver

Intelligent Power Modules (IPM) has not only integrated with power switching devices and gate drive circuits, but also contained some fault detection circuits: under-voltage lockout, over- voltage protection, thermal-shutdown and over-current protection to insure the safe and reliable operation and service life of the IPM. Coupled with compact flexible features and convenience, the IPM now has widely used in various fields, such as aerospace, automotive electronics, industrial control and consumer electronics etc.In this paper, as a typical IPM, a kind of H-bridge drive circuit was designed and could be used in situations of low-voltage,low-power for brushless DC vibration motor's drive. Based on the PWM control principle and the CMOS processing , this design can work under the power supply voltage ranging between 2V～4V and a wide operating temperature range:-25℃～125℃. It also contains the automatic detection and protection about the under-voltage lockout and thermal-shutdown and besides, the dead-time circuit of H-bridge and the control function of motor anti-death are designed to improve the motor's function.This paper starts from the introductions of Brushless DC motor mathematical model and its startup characteristics, and then give the overall design concept of the H-bridge driver circuit: It has planned some specific function modules and the interfaces between them; and focused on the design of start-up time control circuit, the PWM control circuit, the anti-death-point control circuit and the H-bridge specific structure; and then analyzed the ring oscillator, under-voltage lockout and thermal-shutdown circuit in details. After the completion the design of specific circuit, it uses Spectre simulator which integrated in Cadence for circuits'simulations and results analysis through the CSMC 0. 5?m CMOS processing to verify the accuracy of design. Finally, the design of the whole circuits'layout and post simulations after DRC, EXT and LVS process are completed and the results meet the performance requirements.