A voltage supply for an electronic device, such as a hearing aid instrument, to be worn on the body of a user. The voltage supply has a charge pump for converting a battery voltage by a conversion factor to an intermediate voltage. The charge pump can be changed over between at least two stages of the conversion factor. The voltage supply furthermore has a voltage regulator for reducing the intermediate voltage to an output voltage of a predefined setpoint value and a controller for reversibly changing over the charge pump between the stages of the conversion factor. The controller is configured to actuate the charge pump in accordance with a manipulated variable of the voltage regulator.