Patent ID: 8878387

Claim:
An integrated circuit receiving a positive power supply voltage and a negative power supply voltage forming a rail-to-rail power supply, the integrated circuit comprising: a multi-level stack voltage generator configured to partition the rail-to-rail power supply into one or more reduced supply voltages, the one or more reduced supply voltages each having a voltage value between positive and negative power supply voltages of the rail-to-rail power supply, the one or more reduced supply voltages and the positive and negative power supply voltages being configured in series to form a stack of circuit layers, each pair of adjacent supply voltages providing power to a circuit layer; and a core circuit comprising a plurality of core circuit units, each of the core circuit units being coupled in a circuit layer or coupled between two or more circuit layers, each core circuit unit being coupled to at least one of the reduced supply voltages, wherein the core circuit units are coupled in the stack of circuit layers to form a serial connection of core circuit units between the positive power supply voltage and the negative power supply voltage, and wherein the multi-level stack voltage generator comprises: a reference voltage generator configured to generate one or more reference voltages, each reference voltage being associated with a reduced supply voltage; a sense amplifier coupled to each circuit layer and configured to receive a reference voltage and a reduced supply voltage of each respective circuit layer and to generate an error signal indicative of the different between the reference voltage and the reduced supply voltage for the respective circuit layer; a power control unit coupled to each circuit layer and configured to receive the error signal and to generate a control signal indicative of the error signal; and a power adjust unit coupled to each circuit layer and configured to adjust a sinking current to or a sourcing current from a respective reduced supply voltage in response to the control signal so that a current flow in the stack of circuit layers are balanced with each circuit layer sharing the same current.