Research On 600V Power Half-bridge Driver Circuit

It is a major national strategy to promote the development of IC industry.It is the basic element of social progress to advocate energy conservation and emission reduction.Power integrated circuit has the advantages of low power consumption,low cost,high efficiency and high reliable,which is favored in the field of power electronics.Power driver circuit is a typical power integrated circuit,which can reduce the switching loss of power devices and improve the energy utilization.It is widely used in the display driver,automotive electronics,motor driver,power management and other fields.Based on 1?m 600 V BCD process,a 600 V power half-bridge driver circuit is designed for LED lighting driver in this paper.The design requirements of driver circuit are as follows: high side floating voltage is 600V;the peak output current reaches ±2A;the highest operation frequency is 500kHz;the dead time is 500ns;input terminal is compatible with 3.3V/5V TTL/CMOS signal;it is satisfied the logic ground and power ground with ±5V common mode offset;it should have Electrostatic Discharge(ESD)protection,over current protection,undervoltage protection and other functions to ensure the safe and reliable operation of the whole circuit.In this paper,according to the functional requirements of LED lighting driver,the design requirements of 600 V power half-bridge driver circuit are determined.The overall circuit is divided into logic control module,driver module and protection module.Then,the working principles of Schmitt Trigger circuit,improved low voltage level shift circuit,high voltage level shift and output stage driver circuit are analyzed,and simulation verification is performed based on Spectre software.Subsequently,the basic mode of ESD and ESD protection methods are introduced.The working principle analysis of proposed ESD power clamp is carried out.The simulation results prove that the proposed ESD power clamp has excellent ESD performance.Finally,the overall function simulation of normal operation,low sidepower supply under-voltage,high side power supply under-voltage and over-current condition is performed on the 600 V power half-bridge driver circuit.And the parameters of overall circuit is simulated and sorted.The overall function of driver circuit meets the design requirements.The innovative works of the 600 V power half-bridge driver circuit designed in this paper are as follows:1.In the view of the fact that the traditional low voltage level shift circuit cannot achieve isolation between the logical ground and the power ground,an improved low voltage level shift circuit is proposed,which can not only achieve isolation between the logical power supply from the power supply and the isolation between logical ground from the power ground,but also satisfy the logical ground and power ground with ±5V common mode offset to avoid the mutual interference between the control circuit and the power circuit.2.Aiming at the shortcoming of simple structure in the traditional output stage driver circuit,the improved output stage driver circuit is proposed,which can ensure reliable and stable operation of the driver circuit through the latch structure,realize30 ns dead time and reach ±2A output peak current.3.A power clamp ESD protection circuit based on diode string and negative feedback technology is proposed.When a 2kV HBM ESD pulse arrives,the proposed power clamp ESD protection circuit maintains the on-time of BigFET to 550 ns which is six times the on-time of BigFET in the traditional structure.At the same time,the proposed power clamp ESD protection circuit has no power supply power-on false triggering problem,strong anti-noise interference capability and can effectively protect the internal circuit safety in time.