Patent ID: 6184721
Filing Date: 2001-02-06
Classification: H03K

Abstract:
A voltage comparator circuit comprising:a pair of switching elements;a first input element that receives input voltages for comparison;a second input element that receives a strobe signal that indicates a transition from a reset mode to a comparison mode; anda comparison element coupled to the first and second input elements to receive the input voltages and configured to determine which of the input voltages is larger, said comparison element including:a pair of source-coupled input transistors configured to draw current from a supply voltage, the current being proportional to the input voltages applied at the gate terminals of the input transistors, anda pair of cross-coupled load transistors configured to pass the current drawn by the input transistors, where more current is passed by the load transistor whose gate terminal is drawn by the input transistor with higher input voltage,where each of said pair of switching elements are arranged across source and drain terminals of each of said pair of cross-coupled load transistors to prevent any charge or current conduction through the load transistors during the reset mode, which reduces threshold mismatch in the load transistors during the comparison mode.