Patent ID: 8344791
Filing Date: 2013-01-01
Classification: H02M

Abstract:
1. A method comprising: receiving a first power supply voltage at an input of a first charge pump from a first power supply; coupling a first charge pump output voltage and a first charge pump output current from a first output of the first charge pump to a first power supply input of a first functional circuit, the first functional circuit having a first power supply voltage requirement and a first power supply current requirement, wherein the first charge pump output voltage is greater than the first power supply voltage, and wherein the first charge pump output voltage meets the first power supply voltage requirement of the first functional circuit and the first charge pump output current meets the first power supply current requirement of the first functional circuit; and receiving at least one output of the first charge pump at an input of a second charge pump, the second charge pump generating a second charge pump output voltage and a second charge pump output current on a second output of the second charge pump, wherein the second charge pump output voltage is greater than the first charge pump output voltage, and wherein the second charge pump output current is less than the first charge pump output current; coupling the second charge pump output voltage and the second charge pump output current to a second power supply input of a second functional circuit, the second functional circuit having a second power supply voltage requirement and a second power supply current requirement, wherein the first power supply voltage requirement is less than the second power supply voltage requirement and the first power supply current requirement is greater than the second power supply current requirement, and wherein the second charge pump output voltage meets the second power supply voltage requirement of the second functional circuit and the second charge pump output current meets the second power supply current requirement of the second functional circuit, wherein the first functional circuit, the second functional circuit, the first charge pump, and the second charge pump are on a single integrated circuit; wherein the first power supply voltage varies across a range of voltage values; wherein the first charge pump transitions between different modes of operation in response to different values of the first power supply voltage; and wherein the different modes of operation increase the first power supply voltage by different amounts to maintain the first charge pump output voltage above a minimum voltage.