Patent ID: 7427888
Filing Date: 2008-09-23
Classification: H02M

Abstract:
1. A charge pump circuit comprising: a charge pump block including a plurality of charge pump parts, each charge pump part including at least one pre-charge device; a selector circuit coupled to the at least one pre-charge device of each of the charge pump parts, the selector circuit being structured to receive a supply voltage and a high voltage; and a detector circuit comprising a first node, a second node, a high voltage inverter, and a low voltage inverter, the high voltage inverter being coupled to the low voltage inverter, the first node being coupled to the supply voltage and the high voltage, the second node being coupled to an input of the high voltage inverter, the second node having a voltage high enough to invert an output of the high voltage inverter responsive to the high voltage being higher than the supply voltage, the low voltage inverter being configured to provide a detect signal to the selector circuit responsive to the inverted output of the high voltage inverter, wherein the detector circuit further comprises a first high voltage NMOS transistor coupled between the supply voltage and the first node and a second high voltage NMOS transistor coupled between the high voltage and the first node, the first node having-a voltage of one of (a) a difference between the supply voltage and a threshold voltage of the first high voltage NMOS transistor and (b) a difference between the high voltage and a threshold voltage of the second high voltage NMOS transistor.