Patent ID: 7332953

Claim:
A control unit controlling a threshold voltage of a circuit unit having a plurality of transistor devices, comprising: a reference circuit; a measuring unit measuring a threshold voltage of at least one sensing transistor of the circuit unit and measuring a reference threshold voltage of at least one reference transistor of the reference circuit; a differential voltage generator generating a differential voltage from outputs of the measuring unit, the voltage generator comprising an averaging unit, a comparing unit and an amplifier; and a bulk connection of the transistor devices in the circuit unit to which the differential voltage is fed as a biasing voltage; wherein the averaging unit forms at least one average threshold voltage value of at least one measured transistor threshold voltage of the circuit unit; the comparing unit compares at least one average threshold voltage value of the circuit unit with at least one measured transistor threshold voltage of the reference circuit and creating at least one difference voltage value indicating the difference between at least one average threshold voltage value of the circuit unit and at least one transistor threshold voltage of the reference circuit; and the amplifier unit amplifies at least one difference voltage value of the comparing unit and creating at least one amplified difference voltage value.