A band-gap reference circuit including a charge pump circuit and a reference circuit is disclosed. The charge pump circuit is powered by a supply voltage and thereby outputs a regulating voltage which is higher than the supply voltage and powers the reference circuit such that the reference circuit outputs a band-gap reference voltage. Powering the reference circuit with the regulating voltage that is made higher than the supply voltage by the charge pump circuit enables 1) normal operation of the band-gap reference circuit at the supply voltage that is lower than a lowest voltage required by the band-gap reference circuit; and 2) minimization (almost elimination) of fluctuations in the regulating voltage output from the charge pump circuit and hence a stable and more accurate band-gap reference voltage output from the band-gap reference circuit.