Patent ID: 6091287
Filing Date: 2000-07-18
Classification: G05F

Abstract:
A voltage regulator, comprising:a comparator having a first input terminal for receiving a first reference voltage, a second input terminal, and an output terminal for providing a control signal, wherein the first reference voltage is provided by a circuit which causes the first reference voltage to be relatively constant;a voltage source controlled by a power supply voltage, and in response, providing a second reference voltage to the second input terminal of the comparator, wherein the voltage source causes the second reference voltage to vary as a function of the power supply voltage; anda current-to-voltage converter, comprising:a current mirror circuit having a first input terminal for receiving a reference current, a second input terminal for receiving the power supply voltage, and an output terminal;a first transistor having a first current electrode coupled to the output terminal of current mirror circuit, a control electrode coupled to the output terminal of the comparator, and a second current electrode for providing a first output voltage;a first resistor having a first terminal coupled to the first current electrode of the first transistor, and a second terminal;a second transistor having a first current electrode coupled to the second terminal of the first resistor, a control electrode coupled, via an inverter, to the output terminal of the comparator, and a second current electrode coupled to the second current electrode of the first transistor for providing a second output voltage; anda second resistor having a first terminal coupled to the first current electrode of the second transistor, and a second terminal coupled to a ground terminal, wherein the first output voltage is provided in response to the second reference voltage being lower than the first reference voltage and the second output voltage is provided in response to the second reference voltage being higher than the first reference voltage.