Abstract: A convertible charge-pump circuit includes: a charging circuit having a plurality of charging capacitors and a pumping circuit having an output port coupled to a pumping capacitor. The charging circuit is configured for charging the charging capacitors to store a plurality of potential differences, respectively, when the convertible charge-pump circuit is in a charging phase. The pumping circuit is configured for selecting at least one charging capacitor from the charging capacitors charged in the charging phase to generate an output voltage level at the output port according to a potential difference stored in the selected charging capacitor when the convertible charge-pump circuit is in a pumping phase.