Research And Design On High-voltage,High-reliability Half-bridge Gate Drive

In recent years,the improvement of energy efficiency has gradually become an important part of environmental protection.In order to improve the efficiency of electric energy usage,it is necessary to optimize the structure of the transmission path of electric energy.Since the electrical energy will inevitably produce a certain energy loss after being processed and converted by the power module,the most direct way to improve the transmission efficiency is to reduce the number of power modules on the transmission path,and the reduction in the number of power modules also means an increase in the relative applied voltage of each level,which makes future power modules inevitably develop in the direction of higher voltage and higher power density.With the continuous improvement of chip operating voltage and operating frequency,how to ensure its reliability on the basis of improving circuit performance has become the key aspect of design.At the same time,the switching power supply is considered as the EMI emission source in the power system,and its EMI will further deteriorate as the operating frequency increases,and affect the normal operation of peripheral modules.The half-bridge gate driver chip is used as a direct drive of the power switch device,and its performance will directly affect the working state of the power module.As the operating voltage of the chip increases,the dv/dt generated during the switching process increases,which poses a challenge to the CMTI capability of the various sub-circuits inside the chip;and for the increase in the operating frequency of the chip,the internal switching tubes of the chip increase due to The switching loss caused by the supplement and discharge of the charge in each switching cycle will increase in a unit time;at the same time,the EMI noise generated by the half-bridge gate driver chip during the switching process also increases with the increase of the chip application voltage and frequency.It will make a more serious impact on the normal operation of the surrounding power modules.Aiming at the above working scenarios of future power modules,this paper researches and designs a high-voltage,high-reliability half-bridge gate driver chip.In terms of circuit implementation,a high-voltage,high-CMTI level shift circuit is used to achieve signal transmission,and a dual-N-type switch tube solution is used to realize the periodic supplement of the bootstrap capacitor charge of the circuit;at the same time,a segmented drive control solution is used to realize the chip EMI control.Based on the 0.18?m 100 V BCD process,this paper has carried out design realization and simulation verification on the key technology.The design of level shift circuits with a CMTI capability of 200V/ns is realized;at the same time,the switching loss of the chip is reduced at high frequencies by optimizing the buffer circuit and the bootstrap charging circuit structure;driving by segment The control scheme suppresses the EMI noise during the switching process of the power device.The simulation results show that the chip can work normally at an external application voltage of 90 V and a maximum operating frequency of 10 MHz.Besides,the ringing phenomenon is greatly reduced.