| With the continuous development of human electronic technology and the advent of the mobile Internet era,our lives are inseparably related to various electronic products.At the same time,as the core of all kinds of electronic products,how to use the power reasonably,efficiently,stably and safely has always been a subject of continuous exploration and in-depth research.After years of research,compared with other primary batteries,lithium batteries are widely used in various electronic products because of their advantages.As the application of lithium batteries has become more and more widespread,corresponding power management chips have gradually developed.Among them,allowing the lithium battery to supply power to other modules of the system stably and efficiently is an extremely important part of the power management chip,and it is also an aspect that researchers have been researching and improving for many years.With the continuous development of electronic technology,switch mode power supplies are widely used in various power management chips due to their high efficiency and small size.This article analyzes the performance advantages and development status of switch mode power supplies,and introduces the basic circuit structure and working principle of DC-DC converters.On this basis,a high-efficiency boost DC-DC converter chip applied to lithium battery management systems is designed.In view of the characteristics of the lithium battery and the demand of the back-end load,the input voltage of the DC-DC converter chip designed in this article is 2.5V-4.5V,and the output voltage is 5V.The chip adopts a synchronous rectifier circuit structure,which reduces the power loss on the freewheeling diode.Each module of the chip can work normally in the voltage range of 2.5V-4.5V.The chip adopts PFM modulation method to improve the efficiency under light load.The voltage feedback mode is adopted to simplify the circuit structure and save the area cost.The chip also has a temperature Protection module and voltage detection module to ensure that the chip works in a normal environment.This article adopts 0.5μm HHGRACE CZ6 LPLUS craft,carries on the design to the circuit,uses Cadence Spectre tool to carry on the simulation verification to the chip.The results show that the chip stops working at 140°C and resumes normal operation when the temperature drops to 110°C.Its input voltage is 2.5V-4.5V,output voltage is 5V,voltage ripple is less than 80 m V,and the minimum efficiency is above 60%.The overall efficiency is around 80%,and the highest efficiency can reach more than 90%.In the load change range of 50 m A-500 m A,the output load adjustment rate is about 1%.When the input voltage or load fluctuates,the system’s dynamic linear adjustment rate and load transient response are good.Finally,the actual performance of the circuit is tested by using the chip to build the circuit,and the result is consistent with the simulation result,indicating that the chip designed in this paper has higher efficiency and stability. |
