US 5,349,286 A · Compensation for low gain bipolar transistors in voltage and current reference circuits

Abstract

A bandgap reference circuit 30 includes a current generation circuit 32, a voltage generation circuit 34 connected to current generation circuit 32, and a compensation circuit connected to current generation circuit 32 and voltage generation circuit 34. Current generation circuit 32 sources a current to voltage generation circuit 34 which translates the current into a voltage. Compensation circuit 36 monitors current generation circuit 32 and provides a supplemental current to voltage generation circuit 34. Voltage generation circuit 34 receives the supplemental current and translates it into a supplemental voltage. The summation of the voltage produced by the current received by current generation circuit 32 and the supplemental voltage produced by the supplemental current received by compensation circuit 36 produces a stable reference voltage.

Claims13

Dependent claims

A bandgap reference circuit, comprising:

a current generation circuit having a bipolar transistor;
a voltage generation circuit connected to the current generation circuit;
and
a compensation circuit connected to the current generation circuit and the voltage generation circuit, wherein the compensation circuit monitors a current magnitude of the current generation circuit and provides a supplemental current to the voltage generation circuit in response to the current magnitude of the current generation circuit, the supplemental current creating a supplemental voltage in the voltage generation circuit, the supplemental voltage having a magnitude that cancels an error associated with a finite gain of the bipolar transistor.

1 more element

A method of providing a stable reference signal, comprising the steps of:

generating a base-emitter voltage difference between a base-emitter voltage of a first bipolar transistor and a base-emitter voltage of a second bipolar transistor;
translating the difference in base-emitter voltages of the two bipolar transistors into a preliminary reference current, wherein the preliminary reference current is proportional to the difference in base-emitter voltages of the two bipolar transistors;
measuring a summation of a base current of the first bipolar transistor and a base current of the second bipolar transistor;
generating a supplemental current, wherein the supplemental current is a ratio of the base current required by two bipolar transistors;
and
adding the supplemental current to the preliminary reference current, wherein the sum of the preliminary reference current and the supplemental current form a stable reference current that is independent of variations in the gains of the two bipolar transistors.

3 more elements

Dependencies are inferred from the claim text.

Compensation for low gain bipolar transistors in voltage and current reference circuits

Life of this patent

Compensation for low gain bipolar transistors in voltage and current reference circuits

Life of this patent

Abstract

Claims13