Design And Investment Of An H-bridge DC Electronic Motor Driving IC

With the improvement of IC design proficiency,Smart Power Integrated Circuit（SPIC）has been applied in various industries with the advantages of low cost and high performance.As a typical SPIC,the motor driving IC has broad application prospects in automobile,printing equipment and other fields,so it is of great significance to carry out in-depth research on motor driving IC.This thesis designs a DC motor driving IC based on 0.35 μm 80 V BCD process.Its typical operating voltage is 42 V,output current is 0.9～4 A,the on resistance of the power transistor is less than 0.5 Ω.This IC includes high-voltage charge pump circuit,highvoltage bias circuit,high-voltage LDO circuit,PLL circuit,low-voltage digital logic control circuit,voltage detection circuit,boostrap circuit,high-voltage bandgap reference circuit and so on.Firstly,high voltage bias circuit,high voltage LDO circuit and high voltage bandgap reference circuit are designed in the motor driving IC to provide stable power supply for each sub-module of the IC,which reduces power consumption and improves the reliability of the IC.Secondly,a low power PLL circuit is designed to provide 10 MHz operating frequency for the high voltage charge pump circuit,so as to control the charging of the charge pump capacitor.At the same time,the PLL circuit also provides highfrequency signals for the digital logic control circuit to generate control signals for the Hbridge drive circuit,and can also drive a three-phase DC motor by using multiple chips.In order to quickly refresh the gate charge of the high-side power transistor,a high-voltage charge pump circuit with a frequency of 10 MHz is designed based on the fast conversion high-voltage level shift circuit.Combined with the bootstrap circuit,a stable 0～54 V highvoltage control signal can be provided for the gate of the high-side power transistor.The voltage detection circuit in the high voltage charge pump circuit is able to prevent the darlington transistor in the charging branch from being broken down.Finally,in order to prevent the power transistors on the same side of the H-bridge from punching through and short circuit,the RC delay module is added to the low-voltage CMOS digital logic control circuit and bootstrap circuit to produce the dead time,which improves the reliability of the IC.The schematic diagram and layout of the motor driving IC are designed by Cadence.The overall simulation of the motor driving IC is carried out,when the voltage is 42 V,the output current of the IC is 0.9～4 A.The motor driving IC can control the speed,steering,braking and output current of the motor.The H-bridge motor driving IC designed in this thesis meets the functions and indexes of the design requirements.