A voltage generating circuit includes an input stage, a control stage, an inductor and an output stage. The input stage includes a plurality of comparators each generating a comparison result according to an input voltage and a reference voltage and a multiplexer configured to output a voltage control signal sequentially carrying the comparison results of the comparators. The control stage is configured to control conduction of a charging path between a power source and a first node in response to the voltage control signal. The inductor is coupled between the first node and a second node. The output stage includes a plurality of output switches coupled to the second node and turned on or off in response to a switch control signal. The switch control signals are generated according to the voltage control signal and rising edges and falling edges of the switch control signals are interleaved.