Design Of A DC/DC Boost Converter With Soft Start-up Capability

Today,mobile electronic devices are used in various fields,such as aerospace,home,industrial production and medical treatment.And as the core design of mobile electronic equipment-power management chips also occupy a pivotal position.The power supply of mobile devices is usually a battery,and the voltage supplied by the battery is usually not sufficient to provide the charging voltage inside the device.Therefore,the internal circuit needs for a high efficiency,small size DC-DC Boost chip,is characterized by the DC-DC boost chip for market demand.In this paper,a high efficiency PWM control voltage mode boost conversion circuit is designed.Firstly,the basic principle of the boost DC-DC circuit is introduced,then the design principle of the sub module of the system is introduced,and the innovative design of soft start circuit,the amplifier and under voltage protection circuit are described in detail.In order to improve the service life of the chip,the over temperature protection module,soft start module and under voltage protection circuit are designed,when the input voltage is too low or the chip temperature is too high,the system will automatically turn off circuit.The output voltage of the circuit can presents a stairs type to continuously rise when the circuit is started.Second,in order to integrate the chips,the power transistor is placed inside of the chip to reduce the discrete components.Finally,through the Cadence software simulation of the whole system,simulation results show a stable output of 10 V voltage can be obtained for the DC-DC converter chip.The maximum load current is 100 mA.Ripple is less than 35 mV.This paper introduces the amplifier,bandgap reference,oscillator,over temperature protection soft start circuit and under voltage protection circuit design.Based on the sub module design,the whole DC-DC boost chip is completed.The design of whole circuit is based on 0.25?m vis25 cb technology,Virtuoso and Calibre software are used to verify the DRC and LVS of the layout,and Cadence Spectre is used for system simulation.The simulation results are consistent with the design goal.