A current pumping circuit includes a voltage detector, a boost circuit, and an output circuit. The voltage detector detects a level of a power voltage and outputs a corresponding control signal. The boost circuit controls the power voltage to be maintained at a predetermined level based on the control signal. The output circuit provides an output signal regardless of the level of the detected voltage. The output circuit may include or be coupled to a data converter, which generates the output signal based on a transmission signal and the boosted power voltage. The transmission signal may be one output from a predetermined control circuit.