Design and Implementation of Low Voltage, High Current, High Efficiency DC-DC Buck Converter

Abstract

Buck converters are step-down DC-DC converters that are widely being used in different electronic devices like laptops, PDAs, cell phones and also electric vehicles to obtain different levels of voltages. These converters are normally, high frequency switching devices operating on PWM principle. The need for more and more lighter and smaller electronic devices propels the need for reduced size of converters operating at higher load currents.

As the processing speed of computer microprocessors increases, consequently number of transistor increases in it. Therefore to decrease the power consumption, the operating voltages of computer microprocessors is reduced below 2V . At the same time, it is expected that these processors will require much more current and will present even more dynamic loads than todays microprocessors. To keep the distribution losses low at an increased power level, the input current of the new generation of on-board dc/dc converters has to be increased.

A study of different topologies that can be used for high current, low voltage applications is carried out in this work duration. Based on this a Multi-phase Buck Converter Topology is selected and simulated for four phases, which delivers power from a 12V input to a 1V /100A resistive load with high efficiency. The control pulses are generated using LPC1768 controller, TLP 250 is used as MOSFET Driver, four inductors of same value have been designed. The open loop results of four phase Buck Converter have been observed and analyzed.