1. A data storage device comprising: a non-volatile memory; and control circuitry comprising an interface operable to receive a supply voltage, and a capacitor, wherein the control circuitry is operable to: use an operating voltage regulator to convert the supply voltage into an operating voltage used to operate the non-volatile memory; use the supply voltage to charge the capacitor to a capacitor voltage higher than the supply voltage; and during a power failure: use a backup voltage regulator to convert the capacitor voltage into a backup voltage substantially equal to the supply voltage; and use the operating voltage regulator to convert the backup voltage into the operating voltage used to operate the non-volatile memory.