Reference circuit for supplying a reference current with a predetermined temperature coefficient

Claim 1

A reference circuit for supplying a reference current with a predetermined temperature coefficient, which circuit comprises first means for generating a first reference current with a negative temperature coefficient, second means for generating a second reference current with a positive temperature coefficient, and third means for generating the reference current with the predetermined temperature coefficient on the basis of the first and the second reference current, characterised in that the first means include a first non-linear current mirror comprising at least a first unipolar input transistor having a gate, having a drain coupled to the gate of the first unipoilar input transistor, and having a source, a first unipolar output transistor having a gate coupled to the gate of the first unipolar input transistor, having a drain, and having a source coupled to a first supply terminal, and a unidirectional unipolar element coupled between the source of the first unipolar input transistor and the first supply terminal, and a first further current mirror having at least a first input terminal coupled to the drain of the first unipolar output transistor, having a first output terminal coupled to the drain of the first unipolar input transistor, and having a first emitter terminal coupled to a second supply terminal, in that the second means include a second non-linear currrent mirror comprising at least a second unipolar input transistor having a gate, having a drain coupled to the gate of the second unipolar input transistor, and having a source, a second unipolar output transistor having a gate coupled to the gate of the second unipolar input transistor, having a drain, and having a source, a first unidirectional bipolar element coupled between the source of the second unipolar input transistor and a third supply terminal, and a second unidirectional bipolar element coupled between the source of the second unipolar output transistor and the third supply terminal, and a second further current mirror comprising at least a second input terminal coupled to the drain of the second unipolar output transistor, a second output terminal coupled to the drain of the second unipolar input transistor, and a second emitter terminal coupled to a fourth supply terminal, and in that the third means have a third input terminal coupled to the first input terminal, a fourth input terminal coupled to the second input terminal, and a reference terminal for supplying the reference current with the predetermined temperature coefficient.