A combined all-digital PLL-buck slack regulation system with autonomous CCM/DCM transition control and 82% average voltage-margin reduction in a 0.6-to-1.0V cortex-M0 processor

Integrated Voltage Regulation (IVR) using buck converters enables efficient, fine-grained supply-voltage control in modern SoC domains [1]. However, existing IVR implementations face several challenges. As voltage domains continue to shrink, reduced per-domain decoupling capacitance requires rapid IVR transient response, leading to unfavorable efficiency and supply droop margin trade-offs. Additionally, digital domains exhibit a wide load current (I
_load
) range, requiring capabilities for autonomous transition between Continuous Conduction Mode (CCM) and Discontinuous Conduction Mode (DCM). All-digital IVR solutions are particularly desirable for ease of integration in SoCs.