Apparatus and methods for charge pumps are disclosed herein. In certain configurations, a charge pump includes a mode control circuit, a clock generation circuit that generates a clock signal, two or more switched capacitors, and a capacitor charging circuit used to charge the switched capacitors in response to transitions of the clock signal. The mode control circuit can be used to operate the charge pump in one of a plurality of modes associated with different clock signal oscillation frequencies and with different power supply voltages of the capacitor charging circuit. For example, in certain configurations, the selected mode can control an oscillation frequency of clock signal and a voltage level of a power supply voltage used by the capacitor charging circuit when charging the switched capacitors.