Patent ID: 6522114
Filing Date: 2003-02-18
Classification: G05F

Abstract:
A low dropout voltage regulator comprising:an input port for receiving an input voltage signal; an output port for providing a regulated output voltage signal; a bandgap reference interposed between the input port and ground for providing a reference voltage signal; a voltage divider comprising a first and a second resistor interposed between the input port and ground; an error amplifier having a first input terminal coupled to the band gap reference, an output terminal coupled to a first node interposed between the voltage divider and the input port and a second input terminal coupled to a second node interposed between the first and the second resistor of the voltage divider, the error amplifier for comparing a bandgap reference signal received at the first input terminal with a feedback signal received at the second input terminal and for providing a first output voltage signal in dependence thereupon; a X1 buffer having a first input terminal coupled to the output terminal of the error amplifier, a second input terminal coupled to the output port and an output terminal coupled to a gate terminal of a pass transistor, the pass transistor having a source terminal connected to the input port and a drain terminal connected to the output port, the X1 buffer for providing gain to the first output voltage signal in order to drive a load connected to the output port; and, a low pass filter interposed between the first node and the X1 buffer for filtering the first output voltage signal.