Study And Design Of Key Circuits In Fully Integrated Single-phase Brushless DC Motor Control Chip

Brushless DC motors have the incomparable superiority that a common brush DC motorsand induction motors don’t have: controllability, wide speed range, low loss and fever rotor,high efficiency, and low cost. Therefore, single phase brushless DC motor has been widelyused in household andindustrial use of micro motor products. In recent years, the singlephase DC brushless motor control chip attachs more and more importance. However, researchand design of the fully integrated single-phase DC brushless motor control chip has occupiedthe mainstream position.The research and design of a fully integrated single phase brushless DCmotor controlchip is descriped in this paper and the main work includes:1、 Designing the circuit system of the control chip. Focusing on the design of theBandgap reference、Low dropout linear regulator with the output of6V、Low dropout linearregulator with the output of1.8V、 Duty ratio control circuit module、 Built-in powerMOS driver circuit module. The simulation results show that Bandgap reference’s output is1.22V, power supply rejection ratio is70.6dB; Low dropout linear regulators’ outputs are6Vand1.8V, power supply rejection ratioes are63.7dB and67dB; the carrier frequency of theDuty ratio control circuit module is25KHz. When the input control voltage changes from0.75V to3.75V, the output signal’s duty ratio changed from0%to100%linearly.2、 Through the method of integrating the high-voltage power device DMOS and lowvoltage CMOS circuit on a silicon wafer, using the Global Foundry180nm BCD technologyto design layout and verificate the chip. The total chip area is1476um×1450um, the LDOmodule area is396.315um×622.42um, the DUTM module area is94.745um×415.295um,the DRIVER module area is783.885um×1380.34um. The test of the real control chip showsthat the operating supply voltage is12V, the working current is0.5A; the LDO module’sstable outputs are6V and1.8V; when the input control voltage changes from0.75Vto3.75V, the motor speed changed from4660rpm to0rpm linearly. So the chip realized thefunction of linear motor speed regulation with analog voltage.