Analysis and design of a current mode buck converter with digitally controlled output voltage

This paper presents the analysis and design of a current mode buck converter whose output voltage is set by a digital potentiometer programmed through an inter-integrated-circuit interface ((IC)-C-2). This converter can handle up to 300W output power, it has an input voltage of 48V and the output voltage ranging from 1.5V up to 40V with a maximum output current of 7.5A. This converter has a high voltage, high efficiency, fixed frequency controller with programmable soft start, undervoltage lockout, current limit unaffected by duty cycle and internal high voltage regulator for its gate driver. This CMC buck converter was designed to be integrated in a computer controlled unit for electronic devices characterization (CCUEDC) [4] as an upgrade of the internal hysteretic buck converter. It can be also integrated in a highly efficient and versatile lab power supply or to be used to power LEDs devices.