A 80v-class Bcd Process-based H-bridge Drive Circuit Design And Realization

Smart Power Integrated Circuit has been used successfully in the area of automation technologies, medical apparatus and instruments, automotive electronics, especially in the area of military, aeronautics and astronautics. A monolithic power driver integrated circuit is designed and fabricated in this dissertation based on the 80V BCD (Bipolar-CMOS-DMOS) process. It accepts an input supply voltage ranging from 12V to 50V, giving a serial current output of 3A, less than 25mA static current and typical 3W power dissipation. It makes the VDMOS power device and control circuit based on Bipolar, CMOS in the same chip and features in latch-up at low-voltage, protection against overheat, over current and current sense.Firstly, architectural structure and basic principles of H-bridge motor driver are given in this dissertation. The whole chip diagram was proposed according to the design specification and the whole chip operational principle was introduced. Secondly, based on the whole chip function requirements, sub-block design and simulation were completed, including oscillator, charge pump, bootstrap, low driver and logic control. The frequency and duty cycle of periodic signal generated by oscillator which can be adjusted in large range and are little influenced by the change of process. A novel level shifter was proposed and it has simple structure and low power consumption. Adopting oscillator, charge pump and bootstrap circuit, the problem of the switch of high side power driver has been solved. After completing the whole circuit simulation, layout and verification, the chip has been fabricated and finally the chip testing is completed.This dissertation describes the whole process of development, which includes circuit principles, simulation practice, layout and testing. Based on the circuit principle analysis, the sub-block circuits and the whole chip circuit are simulated by applying the spectres under Cadence environment. The simulation results indicate that the H-bridge power driver has achieved the design specification. The device models used in circuit simulation were modified after the taping out, thus greatly improving the accuracy of the simulation.