LOW-LOSS STEP-UP AND STEP-DOWN VOLTAGE CONVERTER

摘要

A switch-mode DC-DC voltage converter including a boost stage in the form of a charge pump and a buck stage. Control circuitry is provided that enables the operation of the buck stage while the charge pump stage is also enabled, followed by disabling of the charge pump stage as the input voltage and output voltage increase. The buck converter stage is constructed so that it regulates the output voltage at a voltage above that which disables the charge pump stage. Conduction losses in the main current path, due to the necessity of a power FET or other switching device, are avoided.

主权项

1. A voltage converter circuit, comprising:
a buck converter stage coupled to an input terminal and to an output terminal, for driving a voltage at the output terminal responsive to an input voltage at the input terminal; a charge pump stage, coupled to the input terminal and to the output terminal, for driving a voltage at the output terminal responsive to an input voltage at the input terminal; and control circuitry, for disabling the charge pump stage responsive to the voltage at the output terminal being above a first output voltage level, and for controlling the buck converter stage to regulate the output voltage at a second output voltage level, wherein the second output voltage level is above the first output voltage level.