Patent ID: 6693458
Filing Date: 2004-02-17
Classification: H03K

Abstract:
An apparatus for comparing an input signal to a reference voltage, comprising:(a) a high comparator that is operable to resolve up to a positive rail of a power supply, wherein the high comparator is employable to compare the reference voltage to the input signal; (b) a low comparator that is operable to resolve up to a negative rail of the power supply, wherein the low comparator is employable to compare the reference voltage to the input signal; and (c) in response to the input signal, a selector that is operable to select one of the high comparator and the low comparator to compare the input signal to the reference voltage, wherein an unselected one of the high comparator and the low comparator is disabled by the selector, and wherein in response to comparing the input signal to the reference voltage, a comparison signal is generated by the selected one of the high comparator and the low comparator.