Research And Design Of Booster DC-DC Power Conversion Chip

With the rapid development and innovation of power electronic technology,DC-DC power converter is widely used in various fields,especially in optical fiber communication.At the receiver of optical fiber communication,the electrophotonic detector is generally reverse biased,and the weak optical signal received is converted into electrical pulse signal by photoelectric effect.Therefore,it is necessary to provide bias voltage to make it work in the reverse biased condition.However,as the bias voltage is high,the power supply voltage used by the optical receiver is not enough to enable the photodetector work in the reverse bias condition.In order to solve this problem,this paper designs a booster DC-DC power converter chip suitable for optical receiver which is based on 0.35um BCD process.The chip has the characteristics of low input voltage,fast response speed and high stability.Firstly,three topological structures of DC-DC power converter and the commonly used conduction mode,modulation mode and control mode are introduced.According to the working principle and performance index of the power converter,the PWM modulation mode,DCM conduction mode and peak current mode are selected,and the overall structure framework of the chip is constructed on this basis.Secondly,we use the Virtuoso schematic editing tool to design the sub-modules,including the bandgap reference module,current detector module,error amplifier module,PWM comparator module,logic driver module,oscillator module and various protection modules.The error amplifier adopts the current mirror structure instead of the traditional multi-stage op amp structure,which can simplify the chip structure and also remain the transmission gain unchanged with the frequency.The oscillator uses the network to change the size of the charging current and provides a variety of switching frequencies for the chip.The current limiting protection circuit uses the frequency division counting module composed of D flip-flop to set the reference voltage as the step voltage and restrain the inrush current,so as to achieve the purpose of protecting the chip.Then,after completing the circuit design,the chip will be simulated as a whole.The simulation results show that the input voltage range is 3.3V?5V,the output voltage is 10V,the output voltage ripple is maintained within 70mV.The simulation results are consistent with the indicators and achieve the design goal.Finally,based on the function of the chip and index,landscape layout is carried out.Use the Virtuoso layout editing tool to determine the transistor size and complete the layout wiring.After the completion of the layout,DRC and LVS verifications are carried out.