US 11,480,989 B2Granted

High accuracy zener based voltage reference circuit

AssigneeNXP USA, Inc.

InventorsHongwei Liu, Yuan Gao, Estelle Huynh

Life of this patent

Estimating the term…

Loading patent…

Abstract

A voltage reference circuit is disclosed comprising: a supply terminal; a ground terminal; a first current source and a Zener diode connected in series between the supply and ground terminals and having a first node therebetween and configured to supply a Zener voltage at the first node; an output node configured to provide a voltage reference; and a CTAT, circuit connected between the first node and the output node; wherein the CTAT circuit comprises: two bipolar transistors, having their respective emitters connected at a second node, and configured to, in operation, have equal collector-emitter currents, the base of the first bipolar transistor being connected to the first node, the base of the second bipolar transistor being connected to a centre node of a first voltage divider; and wherein the first voltage divider is connected between the emitter of the second bipolar transistor and the output node.

Claims20

Dependent claims

A voltage reference circuit comprising:

a supply terminal configured to be connected to a supply voltage;
a ground terminal configured to be connected to a ground voltage;
a first current source and a Zener diode connected in series between the supply terminal and the ground terminal and having a first node therebetween and configured to supply a Zener voltage at the first node;
an output node configured to provide a voltage reference;
and
a complementary to absolute temperature, CTAT, circuit connected between the first node and the output node;
wherein the CTAT circuit comprises:
a first bipolar transistor and a second bipolar transistor, each having a base, a collector and an emitter, having their respective emitters connected at a second node, and configured to, in operation, have equal collector-emitter currents,
wherein the base of the first bipolar transistor is connected to the first node and the base of the second bipolar transistor is connected to a centre node of a first voltage divider, and
wherein the first voltage divider consists of a first resistance connected between the output node and the centre node and a second resistance connected between the centre node and the emitter of the second bipolar transistor.

7 more elements

A voltage reference circuit comprising:

a supply terminal configured to be connected to a supply voltage;
a ground terminal configured to be connected to a ground voltage;
a first current source and a Zener diode connected in series between the supply terminal and the ground terminal and having a first node therebetween and configured to supply a Zener voltage;
an output node configured to provide the voltage reference;
and
a complementary to absolute temperature, CTAT, circuit connected between the first node and the output node;
wherein the CTAT circuit comprises a first bipolar transistor and a second bipolar transistor having matched emitter currents wherein the first bipolar transistor is configured to receive the Zener voltage at its base, and the voltage reference is derived from a voltage at the base of the second bipolar transistor.

4 more elements

Dependencies are inferred from the claim text.