Patent ID: 6969981
Filing Date: 2005-11-29
Classification: G05F,H02J,H02M,Y02B

Abstract:
1. An apparatus that is arranged to conserve power in a circuit that includes a regulator that provides an output voltage from an input voltage, the apparatus comprising: a window comparator that is selectively enabled in response to a first control signal, wherein the window comparator is arranged to select a reference mode when enabled, wherein the reference mode corresponds to a first mode when the input voltage is within a predetermined range and a second mode when the input voltage is outside of the predetermined range; a reference circuit that is selectively enabled in response to a second control signal, wherein the reference circuit is arranged to provide a reference voltage when enabled; an output comparator that is selectively enabled in response to a third control signal, wherein the output comparator is arranged to selectively activate the regulator by evaluating a reference signal and the output voltage when enabled; a switching circuit that is arranged to select the reference signal based on the reference mode such that the reference signal is associated with the input voltage in the first mode and the reference signal is associated with the reference voltage in the second mode; and a power management unit that is arranged to provide the first control signal, the second control signal, and the third control signal such that the reference circuit and the window comparator are enabled to evaluate the input voltage, the reference circuit is disabled when the first mode is selected, and the output comparator is enabled between switching cycles of the regulator.