Patent ID: 7872519
Filing Date: 2011-01-18
Classification: G05F,H03F

Abstract:
1. A voltage divider circuit, comprising: a first resistor; a constant current circuit for outputting a constant current flowing through the first resistor correspondingly to an input voltage; a first current mirror circuit responsive to the constant current to output a first constant current; a second current mirror circuit responsive to the first constant current to output a second constant current; a second resistor through which the second constant current flows, wherein a potential difference across the second resistor is a function of a current mirror ratio between the first current mirror circuit and the second current mirror circuit, and a resistance ratio between the second resistor and the first resistor; and a MOS transistor having a source connected to the second resistor and turned on to flow the second constant current through the second resistor, the MOS transistor having a gate being biased at the input voltage so that the potential difference becomes a divided voltage of the input voltage.