Multiphase LLC Series Resonant Converter for Microprocessor Voltage Regulation

In order to further reduce the power loss, and increase the computation speed, future microprocessors desires lower voltage, higher current, tighter voltage regulation, and faster transient from their voltage regulators. In the last decade, interleaved buck converters have been studied and used extensively for powering microprocessors. Due to their inherent limitations in current sharing, capacitor size, step down ratio, and energy flow pattern, it becomes very difficult for interleaved buck converters to keep up with the demands of the future microprocessors. In this paper, a new candidate, a multiphase LLC resonant converter is proposed, which features zero voltage switching for both inverter and rectifier switches; wide load range; limited frequency range; fast dynamic response; high efficiency; and automatic current sharing. These features ensure the proposed multiphase LLC resonant converter a good voltage regulator candidate for the next generation microprocessors. All theoretical analyses are verified by a 1 V 50 W prototype and its experimental results