Patent ID: 6121824
Filing Date: 2000-09-19
Classification: G01K,G05F

Abstract:
A low-voltage bandgap reference circuit, comprising:a first bipolar transistor having a first collector, a first base, and a first emitter occupying a first emitter area;a second bipolar transistor having a second collector, a second base, and a second emitter occupying a second emitter area;a first resistor having a first high terminal and a first low terminal;a second resistor having a second high terminal and a second low terminal;a third resistor having a third high terminal and a third low terminal;a fourth resistor having a fourth high terminal and a fourth low terminal;a fifth resistor having a fifth high terminal and a fifth low terminal;a first operational amplifier having a positive first op amp input, a negative first op amp input, and a first op amp output;a first current source for supplying a first current; anda second current source for supplying a second current;wherein the first current source is coupled to the negative op amp input and the first collector;wherein the second current source is coupled to the positive op amp input and the second collector;wherein the first high terminal is coupled to the second emitter;wherein the first low terminal is coupled to the first emitter and the second high terminal;wherein the third high terminal is coupled to the first base;wherein the third low terminal is coupled to the fourth high terminal;wherein the fourth low terminal is coupled to the second base and the fifth high terminal;wherein the fifth low terminal is coupled to the first op amp output;wherein the first current and second current are equal in magnitude; andwherein the second emitter area is a predetermined multiple of the first emitter area.