Patent ID: 6232829
Filing Date: 2001-05-15
Classification: G05F

Abstract:
A voltage reference circuit comprising:a first current source that outputs a first current and a second current; anda difference circuit connected to the first current source, the difference circuit having:a first transistor having a collector connected to receive the first current, a base, and an emitter that outputs a first emitter current;a second transistor having a collector connected to receive the second current, a base connected to the base of the first transistor, and an emitter, the base of the first transistor and the base of the second transistor being electrically coupled to the collector of the second transistor;a third transistor having a collector connected to the emitter of the first transistor, a base coupled to the collector of the third transistor, and an emitter;a fourth transistor having a collector connected to the emitter of the second transistor, a base coupled to the collector of the fourth transistor, and an emitter; anda first resistor having a first end connected to the emitter of the third transistor, and a second end connected to the emitter of the fourth transistor, the first resistor having a first difference voltage across the first and second ends, the first difference voltage having a positive temperature coefficient.