Development of efficient power supply For low voltage high current Applications

Abstract

In order to meet demands for faster and more efficient data processing, modern microprocessors are being designed with lower voltage implementations. The continuous packing of more devices on a single processor chip is increasing its current demands calling for an aggressive power management. These demands, in turn require special power supplies to provide lower voltages with higher currents capabilities for microprocessors. This work presents a modified low voltage high current Voltage Regulator Module (VRM) technology for desktop computers, and portable applications. The developed advanced VRM has advantages over conventional ones in power efficiency and reliability. The SMPS outputs of desktop computers are mainly􀵇5􀜸,􀵇12􀜸. Considering the factor of distribution loss for today’s processors +12V input supply is used instead of +5V and then it is step down to 1.2V. To make this dc/dc conversion efficient at lower voltages, synchronous converter is an obvious choice because of lower conduction loss in the diode. Primarily the various losses occurring in Synchronous Buck Converter (SBC) is analyzed mathematically. The results conclude the dominance of the switching loss on the high side MOSFET. ZVT, the most efficient among the soft switching techniques is employed to the SBC. The suggested Zero Voltage Transition (ZVT) Single Phase SBC is simulated using PSIM for design values of 3.3V, 12A output and switching frequency 200 kHz. The proposed converter exhibits an efficient performance in comparison with the conventional converter. Additionally, the resonant auxiliary circuit in ZVT, which conducts for a short period of time, is also devoid of the switching loss. The simulation results are then verified experimentally by developing a prototype of the proposed converter for a switching frequency of 200 kHz.