A 200mA switched capacitor voltage regulator on 32nm CMOS and regulation schemes to enable DVFS

A wide programmable voltage range combined with fast response times are fundamental requirements for the voltage regulator to enable dynamic voltage and frequency scaling (DVFS) in microprocessors and SoCs. This work investigates the feasibility of a switched capacitor voltage regulator as a solution for distributed power delivery in such systems. In the context of rated currents of several hundreds of mA, this paper closely examines various indices like regulation, losses. ripple, and response times in a representative 1.8V input, 200mA 0.6V-1.05V programmable output complete on-die switched capacitor voltage regulator. Control techniques that can be used to achieve regulation while keeping the losses at minimum under this wide range of operating conditions are delineated. The results are generic and may be used for any other two phase switched capacitor (SC) topology, voltage specifications, and CMOS process. Verification using simulations and experimental results from a converter built on 32nm CMOS are presented. In conclusion, switched capacitor voltage regulators (SCVRs) show fast response times, have multiple high efficiency output voltages, low standby leakage, and inherently high light load efficiency, thereby making them an excellent candidate to enable multiple voltage domains in a chip and to carry out DVFS for power savings.