LOW POWER VOLTAGE REGULATOR CIRCUIT FOR USE IN AN INTEGRATED CIRCUIT DEVICE

摘要

A voltage regulator circuit that receives an input signal and provides an output signal that is clamped at a specified voltage desired for an internal circuit. The disclosed voltage regulator circuit includes a plurality of subcircuits including a voltage tracking subcircuit in which the output voltage tracks the input voltage with no voltage drop when the input voltage starts to rise from zero volts. If the input voltage increases to a desired voltage level for the internal circuit, the voltage tracking subcircuit clamps the output voltage to remain at that voltage. If the input voltage further increases to a higher voltage, the voltage tracking subcircuit is disabled and one of a plurality of voltage maintaining subcircuit takes control so that the output voltage remains at the desired voltage for the internal circuit.