Anti-interference Analysis And Design Of High Voltage Half-bridge Driving Circuit

High-voltage half-bridge drive circuit is the interface circuit between the main circuit and the control circuit.It is often used to drive power devices such as MOSFET and IGBT.It can convert the input TTL/CMOS logic level into high-voltage and high-current output.Therefore,half-bridge drive chip plays a decisive role in the reliable operation of the whole high-voltage system.Half-bridge driver chips are widely used in flat panel display drive,electronic ballast,switching power supply,automotive electronics and other fields.However,due to the limitations of these applications,many reliability problems arise in half-bridge driver circuits,including dV/dt noise,negative overvoltage,electrostatic discharge(ESD)problems.Therefore,the anti-interference capability of the chip in normal operation is required.Very high,the reliability design of half-bridge drive circuit is the main hot research direction at home and abroad.In this paper,a high voltage half-bridge driver chip is designed based on the 1 m 600V BCD process in the laboratory.Characteristic of this chip are:using bootstrap floating principle was carried out on the high side power supply highest floating voltage of 600 V,maximum working frequency of 100 KHZ,maximum peak output current of 2 a,compatible with 3.3 V,5 V TTL logic control signal input,working temperature is 25?125?,and integrates the function of under-voltage protection.This paper introduces the half bridge driver circuit topological structure design of system,analyses the working principle of chip in typical applications,focused on analysis of half bridge driver chips in the dV/dt faced in the practical application of noise,the problem of voltage undershoot,aimed at the two problems of traditional suppression technology is introduced in detail,illustrates the problems existing in the traditional technology,and then half bridge driver circuit is divided into three parts namely the input interface module,power control module,protection module,using Cadence Spectre of each module in detail principle analysis and simulation,The simulation results show that all the parameters meet the design requirements.In the end,the layout design of the half-bridge drive circuit was completed,and DRC,ERC and LVS verification was carried out,as well as post-simulation of the circuit with parasitic parameters extracted from the layout.The main innovative research in this paper includes:(1)An improved common-mode noise cancellation circuit is designed,which can reduce the compromise between the anti-dV/dt noise ability of half-bridge driver chip and the immune ability of negative overshoot,and ensure that the high-voltage half-bridge driver circuit works reliably under high dV/dt noise.The simulation results show that the anti-dV/dt noise ability of the common-mode noise cancellation circuit designed in this paper is 80V/ns,and the immunity of negative overshoot is-10.8V under the bias of power supply voltage 15V.(2)A new ESD Power Clamp circuit used in half-bridge drive circuit is designed.The circuit uses feedback structure instead of traditional RC detection circuit.When ESD comes,it can ensure the opening time of BIGFET in the circuit is about 1 mu s,effectively release ESD current.The capacitance of the detection circuit is only 20 fF,which saves the layout area of the circuit and completely shuts down BIGFET in normal power supply.It does not affect the normal operation of the internal circuit,protects the safety of the internal drive circuit,and improves the reliability of the half-bridge drive circuit chip.