Patent ID: 7411799
Filing Date: 2008-08-12
Classification: H02M

Abstract:
1. A regulated charge pump apparatus, comprising: an oscillator; a gate driver; a charge pump switch, responsive to drive signals from the gate driver, for selectively coupling a load with one of a high voltage signal source and a low voltage signal source; and feedback circuitry having a comparator for comparing voltage at one of said high and low voltage signal sources with a reference voltage, and for providing a signal representative of said comparison to said gate driver to regulate a gate driver signal in its driving of the charge pump switch; said charge pump switch including first and second pairs of MOS transistors; said first pair of MOS transistors coupled between said high voltage signal source and ground, a first terminal of said load being coupled with commonly connected terminals of said first pair of MOS transistors; and said second pair of MOS transistors being coupled between said low voltage signal source and ground, a second terminal of said load being coupled with commonly connected terminals of said second pair of MOS transistors; and said gate driver including a buffer and another MOS transistor; said buffer having an input coupled to receive signals from said oscillator, an output coupled to provide driver signals to a gate of one transistor of one of said first and second MOS transistor pairs, a first reference input coupled to one of said high voltage signal source and ground, and a second reference input; said another MOS transistor coupling said second reference input to the other of said high voltage signal source and ground; said another MOS transistor having a gate coupled to receive said signal representative of said comparison from said comparator; and said gate driver being responsive to said signal received from said comparator to vary said driver signals to said gate of said one transistor of said one of said first and second MOS transistors pairs.