A 0.45–1 V Fully-Integrated Distributed Switched Capacitor DC-DC Converter With High Density M I MC a p a c i t o ri n2 2n mT r i - G a t eC M O S

Abstract

A fully integrated switched capacitor voltage regu- lator (SCVR) with on-die high density MIM capacitor, distrib uted a c r o s sa1 4K Br e g i s t e rfile (RF) load is demonstrated in 22 nm tri-gate CMOS. The multi-conversion-ratio SCVR provides a wide output voltage range of 0.45–1 V from a fixed input voltage of 1.225 V. It achieves 63–84% conversion ef ficiency and supports a maximum load current density of 0.88 A/mm 2. The area overhead of the dedicated SCVR on the load is 3.6%. Measured d ata is presented on various performanc e indices in detail. Subsequent learning on tradeoffs between var ious factors like capacitance characteristics, conversion ef ficiency and cur rent density are de- lineated and, correlated with theoretical estimates. Performance of RF array shows comparable re sults when powered with the SCVR and the external rail. The all-digital, m odular design allows efficient spatial distribution across the load and hence robust power delivery. The extremely fast response times in the order of few nanoseconds is targeted to bene fita gile power management. This work evinces voltage regulator technology as a standard homogenous CMOS component, which can proliferate DVFS domains for maximum energy and area be nefits.