Design Of Full Bridge Motor Drive IC System

As the motor drive chip is applied more and more widely,the speed and cost of the chip are required more and more highly.The development of motor driver chip faces new challenges,so the research of motor driver chip has important practical application significance.In this thesis,based on 0.18μm BCD technology,a H bridge IC for motor drive is designed.Using PWM wave as the input control signal,the maximum operating frequency of the IC is 100 k Hz.The operating voltage of the IC is up to 62 V,and the peak output current is 6A.The external power supply of the driving part of this circuit is 12 V,but the gate voltage of MOS tube cannot exceed 5.5V due to the limitation of the process.Therefore,three kinds of level shift circuits are used in this design to move the 12 V power rail to the4 V power rail to solve the problem of voltage resistance of the device.The pre-step-down circuit and overcurrent protection circuit are added to the design of power circuit submodule,which can enhance the stability of power circuit output voltage.The power supply of the high-side drive circuit is a bootstrap circuit plus a charge pump circuit.In order to ensure the reliability of the high-side power supply,an undervoltage protection circuit is designed in the circuit to monitor the output voltage of the bootstrap circuit to ensure the normal use of the power supply.In this thesis,the influence of diode parameters on the performance of bootstrap circuit is discussed,and the realization method of diode in this circuit is explained.The motor drive IC contains level shift module,power reference,logic module,bootstrap,overtemperature protection,overcurrent protection and undervoltage protection modules.This thesis describes in detail the function and working principle of each module in the designed circuit and the specific circuit used in this design.Simulation is carried out under different conditions to verify whether the data meet the requirements of the index.Finally design the logic circuit,the overall block diagram of the chip,the overall simulation verification.It can be seen from the simulation results that the design results can meet the expected requirements.