Research On Gate Driver Circuit And Key Technology Based On Functional Safety

The control of the power switch in the automotive electronic power unit requires the use of a gate driver circuit.In the design of the gate drive integrated circuit of the vehicle level,functional safety must be introduced.The purpose is to reduce the probability of failure during the application process.To respond to the failure in time,the main purpose is to improve the system safety,and at the same time,the failure mode and effect analysis will be carried out on the driver integrated circuit,propose optimization directions.This thesis focuses on the research on gate driver circuits and key technologies based on functional safety,and proposes a functional safety design method on the basis of completing the circuit design of the three-phase bridge drive.The main work is as follows:1.Propose the overall structure of the three-phase bridge drive system.According to the basic structure of the three-phase bridge,put forward the functional requirements of the three-phase bridge drive circuit,and determine the required specific functional modules based on the functional requirements.2.Based on the 0.18?m BCD process,the design and simulation of all functional modules are completed,mainly including a bandgap voltage reference module with an output of 1.21 V and a temperature coefficient of 11.43ppm/?;two LDO modules with an output voltage of 5V and 12V;output OSC module with a frequency of 500 k Hz;CP module with an output voltage of 14V;protection modules for over-voltage,under-voltage,over-current,over-temperature,desaturation and other protection functions.3.Perform FMEA analysis on all functional modules based on the FMEA analysis method,determine the functional requirements and circuit requirements of each sub-module,analyze the potential failure modes,failure effects and failure causes of each module,and based on this,determine the severity,frequency and frequency of all failure modes.The degree and detection degree are quantified and the corresponding risk sequence number is calculated,and then a feasible optimization method is proposed according to the result of the risk sequence number.Based on the results of FMEA analysis,the specific implementation method of the functional safety design circuit design level of each module is proposed.4.Complete the overall simulation analysis of the three-phase bridge driver circuit,and realize the three-phase bridge driver with functions such as driving capacity greater than 2A,driving voltage 12 V,and multi-level adjustable dead time.Functional safety method and part of the simulation analysis of fault injection are carried out.