A voltage converter includes a driver, a subsidiary voltage converter, an inductor, a capacitor, and a voltage detection unit. The subsidiary voltage converter generates a driving voltage transmitted to the driver to supply working power to the driver. The driver controls the capacitor to be alternately charged and discharged through the inductor, thereby generating an output voltage and output current between the inductor and the first capacitor. The voltage detection unit detects an electric potential difference of the inductor and generates a reference voltage according to the electric potential difference, and the subsidiary voltage converter receives the reference voltage and adjusts the driving voltage according to the reference voltage.