A 0.4V∼1V 0.2A/mm2 70% efficient 500MHz fully integrated digitally controlled 3-level buck voltage regulator with on-die high density MIM capacitor in 22nm tri-gate CMOS

Monolithic integration of Voltage Regulators (VR) is challenging given the inherent lack of scalability of inductor. Circuit techniques to reduce inductor size are attractive to increase power density and scalability. This paper presents a 70∼72% efficient, 500MHz digitally controlled 3-level Buck VR with a fully on-die spiral inductor implemented on 22nm Tri-Gate CMOS with MIM capacitors. The advantages of the 3-level converter for wide range Dynamic Voltage & Frequency Scaling (DVFS) over traditional solutions like linear regulators & Buck VRs are demonstrated.