US 7,071,767 B2Granted

Precise voltage/current reference circuit using current-mode technique in CMOS technology

AssigneeIntegrated Device Technology, Inc.

InventorsQing Ou-yang, Howard Yang, YuFei Gu

Life of this patent

Estimating the term…

Loading patent…

Abstract

A voltage/current reference circuit includes a first bipolar transistor and a second bipolar transistor that exhibit a first voltage drop VBE1 and a second voltage drop VBE2, respectively. A first resistor, having a resistance R1, is configured to draw a first current equal to (VBE1−VBE2)/R1. A second resistor, having a resistance R2, is configured to draw a second current equal to VBE1/R2. A first transistor supplies the first and second currents to the first and second resistors. A second transistor, having a current mirror configuration with respect to the first transistor, directly provides a reference current equal to (VBE1−VBE2)/R1+VBE1/R2. A third transistor, having a current mirror configuration with respect to the first transistor, provides a current equal to the reference current to a third resistor having a resistance R3 and a third bipolar transistor that exhibits a third voltage drop VBE3, thereby generating a reference voltage.

Claims18

Dependent claims

A reference circuit comprising:

a first bipolar transistor that exhibits a first voltage drop VBE1;
a second bipolar transistor that exhibits a second voltage drop VBE2;
a first resistor having a resistance R1, the first resistor being configured to draw a first current proportional to (VBE1−VBE2)/R1;
a second resistor having a resistance R2, the second resistor being configured to draw a second current proportional to VBE1/R2;
a first transistor configured to supply the first and second currents;
and
a second transistor configured in a current mirror circuit with the first transistor, wherein the second transistor provides a reference current proportional to (VBE1−VBE2)/R1+VBE1/R2.
a third resistor having a resistance R3 and being coupled in parallel with the first bipolar transistor, the third resistor being configured to draw a third current proportional to VBE1/R3, wherein the third resistance R3 is greater than the second resistance R2;
a third transistor configured to supply current to the third resistor and the first bipolar transistor;
and
an operational amplifier having input terminals coupled to drains of the first and third transistors, and an output terminal coupled to gates of the first, second and third transistors.

8 more elements

A reference circuit comprising:

a first circuit branch including a first bipolar transistor and a first resistor connected in parallel between a first control terminal and a first voltage supply terminal, wherein the first bipolar transistor exhibits a first voltage drop VBE1, and the first resistor exhibits a first resistance R1;
a second circuit branch including a second resistor connected between a second control terminal and the first voltage supply terminal, and a second bipolar transistor and a third resistor connected in series between the second control terminal and the first voltage supply terminal, in parallel with the second resistor, wherein the second bipolar transistor exhibits a second voltage drop VBE2, and the second resistor exhibits a second resistance R2, and the third resistor exhibits a third resistance R3, wherein R1>R2>R3;
and
a third circuit branch including a third bipolar transistor and a fourth resistor connected in series between a reference voltage output terminal and the first voltage supply terminal, wherein the first, second and third circuit branches are connected in a current mirror configuration, such that a reference voltage is provided on the reference output voltage terminal.

1 more element

Dependencies are inferred from the claim text.