Design And Simulation Of An H-bridge Power Driver IC Based On BCD Process

With the development of power integrated circuits (PIC) and semiconductor process, the demand for smart power integrated circuit (SPIC) is more and more widely in modern society. Power driver integrated circuit is typical smart power integrated circuits, its main function is translating an external control signal to power device’s switching signal by logic control module and the signal can control the rotation direction or rotation speed of the motor. This dissertation designs an H-bridge power driver IC based on BCD process. It’s typical operating voltage is35V and it can provide the capacity of1A continuous current output. The peak of current output is3A. The IC includes under voltage lockout and dead time generating function.The principle and process of the two operating modes of the H-bridge are researched in this dissertation based on working principle of the H-bridge. LDMOS devices are used for H-bridge’s four power devices and its high-side power devices gate drive and low-side power devices gate drive are designed independent. The functions of each sub-module are expounded by the viewpoint of system’s modular structure. The sub-module include reference source module, oscillator module, charge pump module, high-side gate driver module and low-side gate drive module are simulated and analyzed by tools. The oscillator is achieved by a single capacitor and comparator. The amplitude of output signal does not change when the reference voltage changes. The oscillator has small occupied area and ease of integration. The high-side gate drive adopts floating potential of ground technologies, let the potential of gate floating based on principle of bootstrap. The bootstrap capacitor is external. To compensate for the potential drop caused by charge leakage, the charge pump affords electric charge for the bootstrap capacitor. Use tools to simulate top circuit to make sure of the effectiveness of the function. When the result achieve the design requirements, do draw layout and verify DRC, LVS, then send to tape out.This dissertation gives a brief introduction to the Cadence design platform, including methods and processes of Cadence platform for circuit design, simulation and layout verification. Using the way that Cadence built-in simulation platform and circuit editor hang together for subject development is efficiency. Compare the simulation results with theoretical analysis to verify the circuit function.