Switched-capacitor regulator with digital feedback

The wireless sensor node makes use of energy harvesters in order to power its modules. However, by nature of these nodes being placed in diverse locations and fluctuating conditions, their energy harvesters obtain unregulated DC voltage. Regulators undertake this problem by appropriately handling the voltage being harvested to power the node. Most regulators today use analog control methods which are inefficient at delivering power, consume a large amount of area, are more vulnerable to noise, and are less dynamic and adaptive. The 65-nm based switched capacitor regulator with digital control feedback presented in this paper addresses these problems by providing tight voltage regulation with an output accuracy of 9.5mV, peak efficiency of 89.02%, and voltage ripple as small as 2.9mV. The digital control used in the system consumes only 8.777μW of power and is able to perform more complex arithmetic to adapt to the regulator's operating conditions.