Patent ID: 8280089

Claim:
A hearing aid having a battery and a microelectronic circuit, said circuit comprising a digital processing core including PMOS transistors and NMOS transistors, a power supply powered by the battery and providing a supply voltage for the digital processing core, a positive bulk biasing voltage generator and a negative bulk biasing voltage generator, the power supply having a controller for controlling the supply voltage, a first output branch having a first linear voltage regulator, a second output branch having a second linear voltage regulator in series with a 2:1 switched-capacitor voltage converter, the positive bulk biasing voltage generator adapted for providing a bias voltage to the positive bulk of the PMOS transistors of the digital processing core, and the negative bulk biasing voltage generator providing a bias voltage to the negative bulk of the NMOS transistors of the digital processing core, suitable for optimizing parameters of the transistors, the controller being adapted for comparing the battery voltage against a first and a second predetermined limit and causing the power supply to provide the supply voltage by the first output branch when the battery voltage is below the first, predetermined limit, by the first output branch in combination with the second output branch when the battery voltage is above the first, predetermined limit and below the second, predetermined limit, and by the second output branch when the battery voltage is above the second, predetermined limit.