High power density, high efficiency system two-stage power architecture for laptop computers

This paper proposes system two-stage power architecture for laptop voltage regulators (VRs). By taking advantage of the Thermal Design Power (TDP) requirement in the laptop, VRs for microprocessor, graphics, DDR memory and main power can share the same first stage with very low design power. The high-efficiency and high-frequency first stage based on switching capacitor technology and second stage design is presented in this paper respectively. Two different designs are illustrated and verified by experiments. One design keeps the similar VR cost as the current single-stage solution and improves VR light load efficiency by 5%. Another design has slightly higher VR efficiency comparing with single-stage solution while reducing the footprint of VR output inductors and capacitors by 25%∼33% and VR total cost by 5%.