Research And Implementation Of Key Techniques For Single Chip Integrated USM Drive Circuit

Miniaturization and low power have became the mainstream trend of portable electronic devices with the development of semiconductor manufacturing,mechanical engineering and motor control theory.As one of the indispensable components in portable devices,motor can be used for camera lens control,tactile feedback,and mechanical control.Ultrasonic Motor?USM?is an emerging research hotspot this year.In addition to the characteristics of miniaturization,USM also has the advantages of large torque,large speed range and strong anti-interference ability.In order to further highlight the miniaturization of ultrasonic motors,the high integration of USM drive circuits has become an urgent application requirement.The main work of this paper is achieving the monolithic integration of USM driver chip.To achieve smaller integration area and fewer off-chip components,the key techniques of the monolithic integrated USM driver circuit are deeply studied and finally realized in this work.These key techniques include topological selection of monolithic integrated USM driver chips,matching network design,chip noise optimization and core sub-module design.Base on fully review to the related papers,this paper summarizes the characteristics and difficulties of USM driving,and determines the driving architecture of Boost+H bridge.This architecture features high feasibility,high drive efficiency,and easy control of drive waveforms.For higher reliability and lower EMI,this paper analyzes the noise of the USM driver chip from the internal chip to the PCB level system and gives a comprehensive optimization.In addition,this paper has carried out the innovative optimization design for the soft start circuit,adaptive dead band circuit,adaptive zero-crossing detection circuit and load current detection circuit in the USM driver chip.After completing the overall circuit design and layout design,the proposed circuit is fabricated in 0.35?m BCD?Biplor-CMOS-DMOS?process in this paper.The experimental results show that the designed USM driver chip has the complete expected function.the proposed soft-start circuit with current-limiting feedback technique makes the output voltage of Boost ramps up to 45 V in 380?s while I_load=500mA The H-bridge and Boost circuits meet the design target in the case of separate tests.With the load of USM,the driver chip can output two-phase sine wave with a phase difference of 90degrees,with ensures USM working normally.The test results verify the theoretical analysis in this paper,and the designed USM driver chip realizes monolithic integration.