Design Of Low Static Current Synchronous Rectification Buck DC-DC Converter

In recent years,domestic cutting-edge application fields such as 5G communication,cloud computing and Internet of things have been growing rapidly,and the market demand of the electronics industry has been rising rapidly,which has put forward higher requirements for the performance of DC-DC converters widely used in electronic devices.Due to the increasing demand for smart wearable devices,bluetooth devices and portable electronic devices,the research on low-power DCDC converter is of great significance.In this paper,a low static current synchronous rectifier Buck DC-DC converter is designed,based on COT control mode to achieve faster transient response,the synchronous rectifier technology and PWM/PFM mode change,within the scope of the converter in different load automatic switching modulation mode,reduce power consumption,can implement high efficiency in a wide load current range.Through the design of low power consumption structure and low power consumption control mode,the converter can work with very low consumption current,especially under light load conditions,and further reduce the overall power consumption of the converter.At the same time,the over-temperature protection,under-voltage locking,zero-crossing detection and other perfect protection modules ensure the reliability of the converter.The converter can support the long time drive of electronic devices such as mobile devices and bluetooth devices loaded with small batteries.The design of this paper is based on 0.5?m CMOS process,and uses Cadence Virtuoso software to complete the design and simulation of the reference voltage circuit,constant on-time generation circuit,protection circuit and other modules as well as the overall circuit,and completed the layout design and chip test.The simulation and test results show that the converter can obtain a stable output voltage with a typical value of 2.3V in the input voltage range of 2.5V ? 5.5V,and realize automatic switching of the control mode.The converter has a static current as low as 270 n A,the output voltage ripple is less than 25 m V,and the efficiency is higher than 85%,which meets performance indicators such as low power consumption and fast transient response.