Study On A Wide Input And Half-bridge Gate Drive PWM Controller

The controller plays an important role as the power management module of electronic products,and the continuous use time of electronic products is the focus of people’s attention.Controller-type power management chips have the advantages of small size,high integration,and high efficiency,but the application of traditional asymmetric half-bridge converters is limited,and its input voltage range should not be too large.How to increase the working voltage range of the chip to become a power supply the research focus of the management chip.In addition,the internal integrated half-bridge gate drive controller provides two drive signals,which can reduce the number of ICs in the halfbridge converter circuit,thereby reducing costs.In this paper,combined with actual engineering projects,a wide-input half-bridge gate-driven PWM controller structure is proposed.The wide input is designed to regulate the voltage of high input voltage sources or input power sources that are subject to high voltage transients,thereby minimizing the need for external surge suppression components.The article first systematically expounds the meaning of this design based on the research background and the development history and research status of the PWM controller.Secondly,it expounds the basic theoretical knowledge of the switching power supply,and then expounds the circuit principles and design parameters of the components of the controller.The reference module,wide-input start-up adjustment module,drive module and undervoltage/overvoltage protection circuit are the core components of the system,in addition to soft start module,restart timing module,over-temperature protection module,etc.The circuit design is based on the analysis of the principles involved in different sub-modules,and finally the chip-level simulation verification of the controller is carried out by building the peripheral circuit.The wide input indicates that the controller needs to withstand a higher input voltage.The pre-voltage reduction process in the circuit fulfills this requirement.The power devices with high voltage characteristics simultaneously bear the role of withstanding high voltage and providing large current.The design of the thesis is based on 0.25 BCD process,and it is verified by Cadence to build sub-module circuit simulation.The design parameters are verified by simulation,and the key electrical characteristic parameters are combined simulations at different temperatures and process angles to ensure that the circuit system can work normally under extreme conditions.The output voltage of the wide input start adjustment module is 7.6V,and the minimum load current is 25 m A.The bandgap reference voltage is 1.25 V,the temperature drift parameter is 30ppm/℃,and the gate control signal generated by the drive circuit is 2A at most.After sub-module verification,the peripheral circuit is built to simulate the controller.The application input voltage range of the controller is 14V～85V,the output voltage is stable at about 3.24 V,and the efficiency is more than 80% under different input voltages,which basically meets the design requirements.