Patent ID: 7411443

Claim:
A circuit for producing a reversed bandgap reference voltage V RBGP , comprising: (a) a first transistor and a second transistor having an emitter area substantially greater than that of the first transistor; (b) first and second resistors coupled in series between a reference voltage conductor and a first conductor, a base of the first transistor being coupled to a junction between the first and second resistors, for producing a first voltage V BE1 (1+1/M) between the first conductor and the reference voltage conductor, wherein V BE1 is a base-emitter voltage of the first transistor and M is a ratio of the resistances of the first and second resistors; (c) a third resistor across which the reversed bandgap reference voltage V RBGP is produced being coupled between the second transistor and the reference voltage conductor, for producing a second voltage V BE2 +V RBGP between a second conductor and the reference voltage conductor, wherein V BE2 is the base-emitter voltage of the second transistor; (d) first circuitry coupled to effectuate forcing collector current of the first transistor to be equal to collector current of the second transistor; and (e) second circuitry coupled to effectuate forcing the first voltage V BE1 (1+1/M) to be equal the second voltage V BE2 +V RBGP .