Multiphase Buck Converter

With the increased computational requirement in the digital processors in these low-voltage-high-current applications, multiphase buck converters remain an attractive solution because of many technical advantages, such as faster transient performance due to less effective inductance, low input and output capacitance requirements due to the ripple cancellation, high efficiency and reduced thermal stress over a wide load current range using uniform current distribution, and improved light load efficiency using phase shedding techniques. Although the multiphase buck converter is an attractive solution for data center, automotive, and smartphone applications, its major advantages like high-frequency and less amplitude of output current ripple due to interleaving operation and ripple cancellation, are limited by the non-idealities like inductor tolerance and phase parasitic mismatch. Also, with the increased number of phases and output current requirements, equal current balancing among the phases remains a concern, failure of which leads to high phase current, inductor saturation, unequal thermal stress, converter instability, and failure. The main objectives of my research work includes

1. Achieving the phase current balancing

2. Developing multiphase buck power stage with high power density and high efficiency

3. Controller design to achieve superior transient performance during load step-up/ step-up and phase shedding