A capacitive DC-DC converter for stacked loads with wide range DVS achieving 98.2% peak efficiency in 40nm CMOS

This paper presents a fully integrated gearbox-type switched capacitor DC-DC converter that is able to provide two stacked loads with a wide voltage range for Dynamic Voltage Scaling (DVS). This combination offers significant efficiency improvements in both the power delivery and the functional blocks. To face the challenges of wide voltage range stacked loads, 7 topologies with custom gate and bulk drive were implemented, together with a threefold fully integrated control loop. This 8-phase interleaved converter has been fabricated in a 40nm CMOS technology. Measurements demonstrate a peak system efficiency of 98.2%, while a best-in-class DVS-range from 0.45V to 0.9V is guaranteed for two independent stacked loads.