With I ~ 2 C Port Voltage Adjustable Dc/dc Design

With the width of semiconductor technology into the nano level, the system on chip will be integrated more and more transistors to achieve more functionality. Also, the energy consumption of a SoC will rise linearly. How to extend the standby time of board computers, smart phones and other portable electronic products and to improve overall system efficiency will be the main factors that affect the products performance. The DC/DC converter with the traditional and analog design method meet the demand for portable electronic products in some cases. But it seems powerless in some situation such as the application of low-voltage highly efficient or the application of the load change frequently. The DC/DC power converter using a combination of digital and analog design methods will meet the complex application requirements of supply environment by the real-time adjustment.The design method of digital controlled Buck DC/DC converter has been discussed in this paper. The chip with an I2C communication interface, an analog-digital converter circuit, a digital-analog converter circuit is able to detect load data and communicate the information with a microcontroller. The microcontroller can adjust the power level output voltage. Compared with the traditional compensation method, The chip uses on-chip compensation in order to reduce the number of I/O port to facilitate the usage of the client. The digital controlled Buck DC/DC converter’s input voltage range is2.7V-5V and output voltage is0.7V-1.8V,25mV step adjustable.This article discusses the controlled chip design idea in detail, the choice of power stage, the compensation network design, as well as the main sub-circuit design. The chip made by130nm lines uses two kinds of modulation PWM/PSM to improve the work efficiency in the full load operating range. The chip has been tasted. The test results show that:the chip meets the design expectations. Also, with the system working in the overload work condition, the system efficiency is greater than90%, with the system working in the light work condition, the efficiency is no less than80%.