Patent ID: 7268529
Filing Date: 2007-09-11
Classification: G05F

Abstract:
1. A reference voltage generating circuit having a band gap part and an output part, wherein the band gap part has: a first resistor and a first bipolar transistor connected in series between a first power supply voltage terminal and a second power supply voltage terminal; a second resistor, a second bipolar transistor, and a third resistor connected in series between the first power supply voltage terminal and the second power supply voltage terminal; and a differential amplifier that receives voltages generated by the first and second resistors, wherein one end of the first resistor is connected to the first power supply voltage terminal, the first bipolar transistor is connected to the second power supply voltage terminal, one end of the second resistor is connected to the first power supply voltage terminal, one end of the third resistor is connected to the second power supply voltage terminal, the second bipolar transistor is connected between the second and third resistors, wherein potential at a connection point between the first resistor and the first bipolar transistor is applied to a first input terminal of the differential amplifier circuit, potential at a connection point between the second resistor and the second bipolar transistor is applied to a second input terminal of the differential amplifier circuit, an output of the differential amplifier is applied to the bases of the first and second bipolar transistors, and wherein the output part has a third bipolar transistor having a base to which the output of the differential amplifier is applied, a fourth resistor connected in series with the third bipolar transistor, a current mirror circuit for transferring current flowing in the third bipolar transistor, and a fifth resistor and a junction type passive element connected in series for converting the transferred current to voltage.