Bandgap reference circuit including resistivity temperature coefficient cancellation circuit, and oscillator circuit including the bandgap reference circuit

Patent metadata

Field	Value
Publication number	US-11789482-B2
Application number	US-202217702482-A
Country	US
Kind code	B2
Filing date	Mar 23, 2022
Priority date	Mar 26, 2021
Publication date	Oct 17, 2023
Grant date	Oct 17, 2023

Abstract

A bandgap reference circuit includes a reference current generation circuit configured to output a bandgap reference current insensitive to a temperature change, by using a first voltage inversely proportional to temperature and a third voltage proportional to temperature. The third voltage is a difference between the first voltage and a second voltage. The bandgap reference circuit further includes a resistivity temperature coefficient cancellation circuit configured to remove a first current proportional to temperature from the bandgap reference current by using the third voltage, and a reference voltage generation circuit configured to output a bandgap reference voltage insensitive to a temperature change by using a second current inversely proportional to temperature and a first resistance proportional to temperature. The second current is generated by removing the first current from the bandgap reference current.

First claim

What is claimed is:

1. A bandgap reference circuit comprising:
a reference current generation circuit configured to output a bandgap reference current insensitive to a temperature change, by using a first voltage inversely proportional to temperature and a third voltage proportional to temperature, wherein the third voltage is a difference between the first voltage and a second voltage;
a resistivity temperature coefficient cancellation circuit configured to remove a first current proportional to temperature from the bandgap reference current by using the third voltage; and
a reference voltage generation circuit configured to output a bandgap reference voltage insensitive to a temperature change, by using a second current inversely proportional to temperature and a first resistor proportional to temperature, the second current being generated by removing the first current from the bandgap reference current.

2. The bandgap reference circuit of claim 1 , wherein the resistivity temperature coefficient cancellation circuit includes a second resistor having both ends to which the first and second voltages are respectively applied from the reference current generation circuit, the second resistor being proportional to a temperature and having one end connected to a first node of the reference voltage generation circuit to which the bandgap reference current is applied, wherein the first current due to the third voltage flows through the second resistor.

3. The bandgap reference circuit of claim 2 , wherein the reference current generation circuit includes a first bipolar junction transistor (BJT) generating the first voltage, a second BJT generating the second voltage, and a first operational amplifier.

4. The bandgap reference circuit of claim 2 , wherein the reference current generation circuit includes a third resistor to which the third voltage is applied, the first current flowing through the second resistor in the resistivity temperature coefficient cancellation circuit having Proportional To Absolute Temperature (PTAT) characteristics identical to those of a current flowing through the third resistor.

5. The bandgap reference circuit of claim 3 , wherein the resistivity temperature coefficient cancellation circuit further includes a first transistor and a second operational amplifier, wherein an input terminal of the second operational amplifier is connected to the third node of the reference current generation circuit and an end of the second resistor to apply an output voltage to a gate terminal of the first transistor, and the first transistor is connected between the end of the second resistor and a ground node.

6. The bandgap reference circuit of claim 4 , wherein the reference current generation circuit includes a fourth resistor to which the first voltage is applied, wherein a current flowing through the fourth resistor has Complementary To Absolute Temperature (CTAT) characteristics that are identical to those of the second current flowing through the first resistor in the reference voltage generation circuit.

7. The bandgap reference circuit of claim 2 , wherein the second current is a current flowing through the first resistor, and the bandgap reference voltage is a voltage applied to the first resistor, wherein the bandgap reference voltage is determined by the first resistor and the second resistor.

8. A bandgap reference circuit comprising:
a reference current generator including first and second bipolar junction transistors (BJTs) and first and second operational amplifiers, the reference current generator being configured to generate a reference current insensitive to a temperature change by using a difference between a base-emitter voltage of the first BJT and a base-emitter voltage of the second BJT;
a resistivity temperature coefficient cancellation circuit including a first Proportional To Absolute Temperature (PTAT) resistor and a third operational amplifier, the resistivity temperature coefficient cancellation circuit being configured to remove a PTAT current from the reference current; and
a reference voltage generator including a second PTAT resistor through which a Complementary To Absolute Temperature (CTAT) current generated by removing the PTAT current from the reference current flows, the reference voltage generator being configured to output a voltage of the second PTAT resistor as a reference voltage,
wherein the base-emitter voltages of the first and second BJTs are respectively applied to both ends of the first PTAT resistor by using the second and third operational amplifiers, and the PTAT current flows through the first PTAT resistor.

9. The bandgap reference circuit of claim 8 , wherein, with respect to the first PTAT resistor, the base-emitter voltages of the first and second BJTs from the reference current generator are respectively applied to both ends of the first PTAT resistor, one end of the first PTAT resistor is connected to a first node of the reference voltage generator to which the reference current is applied, and the PTAT current flows through the first PTAT resistor due to the difference between the base-emitter voltage of the first BJT and the base-emitter voltage of the second BJT.

10. The bandgap reference circuit of claim 9 , wherein, with respect to the first PTAT resistor, a second node of the reference current generator to which the base-emitter voltage of the first BJT is applied and a third node of the reference current generator to which the base-emitter voltage of the second BJT is applied are respectively connected to both ends of the first PTAT resistor.

11. The bandgap reference circuit of claim 8 , wherein the reference current generator comprises:
a third PTAT resistor to which the difference between the base-emitter voltage of the first BJT and the base-emitter voltage of the second BJT is applied; and
a fourth PTAT resistor to which the base-emitter voltage of the first BJT is applied, wherein the reference current is determined by the third PTAT resistor and the fourth PTAT resistor.

12. The bandgap reference circuit of claim 8 , wherein the resistivity temperature coefficient cancellation circuit further comprises a first transistor, wherein an input terminal of the third operational amplifier is connected to a node of the reference current generator and an end of the first PTAT resistor to apply an output voltage to a gate terminal of the first transistor, and the first transistor is connected between the end of the first PTAT resistor and a ground node.

13. The bandgap reference circuit of claim 11 , wherein the PTAT current flowing through the first PTAT resistor in the resistivity temperature coefficient cancellation circuit has PTAT characteristics identical to those of a current flowing through the third PTAT resistor.

14. The bandgap reference circuit of claim 11 , wherein the CTAT current flowing through the second PTAT resistor in the reference voltage generator has CTAT characteristics identical to those of a current flowing through the fourth PTAT resistor.

15. The bandgap reference circuit of claim 8 , wherein the CTAT current is a current flowing through the second PTAT resistor, and the reference voltage is a voltage applied to the second PTAT resistor, wherein the reference voltage is determined by the first PTAT resistor and the second PTAT resistor.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Lee Jusung
• Kim Wooseok
• Kim Taeik
• Jeong Chanyoung

Classifications

• G05F3/30 Primary

  Regulators using the difference between the base-emitter voltages of two bipolar transistors operating at different current densities (G05F3/26 takes precedence) · CPC title

• G05F1/56

  using semiconductor devices in series with the load as final control devices (G05F1/461 takes precedence) · CPC title

• H03K3/011

  Modifications of generator to compensate for variations in physical values, e.g. voltage, temperature {(to maintain energy constant H03K3/015)} · CPC title

• H03K5/24

  the characteristic being amplitude · CPC title

• G05F1/567 Primary

  for temperature compensation · CPC title