Patent ID: 7019499

Claim:
A low noise voltage regulator circuit for generating a stable voltage signal with low noise, the low noise voltage regulator circuit comprising: a reference voltage generator, electrically coupled to a first node, for generating a first voltage signal and outputting the first voltage signal to the first node; a switching circuit, electrically coupled to the first node, a second node, and a switching control signal, for receiving the first voltage signal from the first node, processing the first voltage signal to generate a second voltage signal, and outputting the second voltage signal to the second node, wherein the switching circuit switches between a first state and a second state, when the switching circuit is at the first state, it is substantially equivalent to a voltage follower, the first voltage signal is coupled to become the second voltage signal without being filtered, when the switching circuit is at the second state, it is substantially equivalent to a RC low pass filter, the first voltage signal is filtered to become the second voltage signal; and a stabilizing circuit electrically coupled between the second node and a third node and including a negative feedback path, the stabilizing circuit receives the second voltage signal from the second node and provides the stable voltage signal to the third node.