Abstract: An embodiment for low power-consumption RC oscillator is disclosed. A voltage transforming unit transforms a power supply voltage to an internal voltage. A current mirroring unit is coupled to the voltage transforming unit and receives the internal voltage to provide constant two current outputs with different phases. A current charging/discharging unit includes first and second nodes to receive the two constant current outputs of the current mirroring unit, wherein first and second capacitors are coupled to the first and second nodes, respectively. The first and second capacitors are charged by the two constant current outputs. A voltage sensing and outputting unit is coupled to the first and second nodes, senses voltage levels of the first and second nodes and outputs clock signals when one of the sensed voltage levels is greater than a logic threshold. A pulse generating unit generates pulse signals in response to the clock signals.