Research On Low Power Consumption Power Management ICs For Wireless Sensor Network Nodes

With the rapid development of science and technology in recent years,the demand for information is increasing,and wireless sensor networks have become the most emerging technologies.Because wireless sensor networks are integrated and miniaturized,wireless sensor network nodes become one of the main ways to obtain outside information.Due to the dense distribution of nodes,it takes a long time to work in a complex and changeable environment.Therefore,network nodes require higher energy utilization efficiency.Switching power supplies have been developed for a long time,the design is relatively mature,and the technology is advanced.Therefore,switching power management chips suitable for network nodes are designed to meet the energy demand of wireless sensor network nodes.This paper proposes to design a low-power power management chip and apply it to the actual conversion circuit scheme.After analyzing and studying the typical topological structure of switching power supply,modulation mode,control mode and power consumption.Based on this,the main design scheme of an isolated flyback switching power supply chip suitable for use in this paper is obtained,and a functional protection circuit for improving reliability is added.At the same time,the current mainstream process was analyzed and the BCD process that was most suitable for the design was selected.According to the main design proposal proposed in this paper,first analyze the main functional modules of circuit design from the overall level.Propose a low-power strategy to reduce static loss and switching loss,that is,use low-power internal key circuit modules and efficient modulation mode.At the same time,the overall circuit architecture is designed,and the key circuit module is designed and analyzed on the basis of the overall architecture.The function and performance of the designed module circuit are simulated through Cadence simulation software.In order to achieve low-power design,a low-power internal circuit block and a strategy for adjusting the duty cycle based on load feedback to reduce switching losses are used.The designed indicators of each key module circuit are: bandgap reference voltage output 1.25 V,temperature drift coefficient of 20.41 ppm / °C;linear regulator circuit output stable 5V voltage to other circuit module power supply;the open loop gain of the comparator circuit reaches 75 d B;the response time of the PWM circuit and the driver circuit is short,and at the same time the dead time of the driver circuit design;the overcurrent protection circuit limits the maximum current of the chip to 60mA;overvoltage protection circuitry limits the internal voltage of the chip and reduces signal glitches.Finally,a practical application circuit is designed for the wireless sensor network node low power management chip designed in this paper,and the chip is simulated at the whole level.The simulation results verify that the startup process of the chip is normal and the output voltage ripple rate is 5.27%.The chip can adjust the duty cycle and skip cycle output through load feedback when the load is light or no load.After the overall simulation of the chip,the layout of the chip was designed.