Patent ID: 8106704

Claim:
An apparatus for generating a pumping voltage, the apparatus comprising: a pumping voltage output unit configured to output a pumping voltage and configured to adjust a level of the pumping voltage to maintain a target level of the pumping voltage, wherein the level of the pumping voltage is adjusted according to a change in the level of the pumping voltage; and a release unit configured to adjust the level of the pumping voltage when the pumping voltage reaches a predetermined excessive level which is greater than the target level by an excessive amount that is capable of causing deterioration to a gate of a transistor for receiving the pumping voltage, wherein the release unit comprises: a comparing unit configured to detect the level of the pumping voltage, and activate a sink signal when the pumping voltage reaches the excessive level; and a main sink unit configured to decrease the level of the pumping voltage when the sink signal is activated; and one or more subsidiary sink units configured to selectively receive the sink signal for selectively decreasing the level of the pumping voltage at a rate faster than the rate when only the main sink unit receives the sink signal.