The Design Of Dual Channel Synchronous Buck DC-DC IC

In recent years, the market of DC-DC converter has been larger and larger whilethe fast development of wireless communication, portable product, industrial controllerand image technology. Especially for these DC-DC converters of anti-radiation, highaccuracy, low power consumption, high-speed driver, and low ripple output have abrilliant future in high-end application.According to demand of user, a dual channel, with maxim1.5A output current,high-efficiency synchronous buck DC-DC controller was designed in this thesis. Somekey technologies and basic principles of a DC-DC converter were analyzed firstly inthis thesis; then, according to the design specification and the whole chip operationalprinciple, the chip feedback model and each specific of voltage feedback and currentfeedback was introduced. This chip have so many specification as follow: independentdual-outputs operate180°out of phase, wide Input Voltage Range:6.5V~12V,Adjustable Output Voltage from0.9V to5.5V, max work frequency of500KHz. ThePWM/SKIP pin allows the operating mode to switch from PWM mode to skip modeunder light load conditions. These two modes, along with synchronous-rectifier drivers,dead time, and very low quiescent current, allow power to be conserved and the batterylife to be extended under all load conditions. In addition, this chip are mainly used insome special industrial applications. We used the X-Fab0.6μm Modular Trench SOICMOS technology process for this chip. This process and anti-radiation design ensuredthe reliability and capability of anti-radiation. It guaranteed that this chip has manyadvantages over other power management chip. Based on advantage of each structure,author proposed the whole chip diagram and application of principle in this chip. Andthen, author worked out the inside and outside parameters of whole circuit, and verifiedby simulation relatively. Consequently, design of some sub-circuit was introduced, suchas Error Amplifier, over current/over voltage protection, Band gap reference and drivermodule. At last, author concluded some parameters of Tapeout, test result and theexperience about this project. Finally, the performance of this project fully meetsdemand of user and the design of this chip was basically completed.