High-accuracy CMOS temperature sensor and operating method

• US 10,642,305 B2
• Filed: 03/06/2019
• Issued: 05/05/2020
• Est. Priority Date: 03/08/2018
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Joo Sung, Kim, Joo Seong, Kim, Kwang Ho, Kim, Sang Ho
• Primary Examiner(s): Nash, Gary A
• Application Number:
  US16/294,704
• Publication Number:
  US 20190278316A1
• Time in Patent Office: 426 Days
• Field of Search: 323281, 323313-317, 327539
• CPC Class Codes: G01K 7/01 using semiconducting elements having PN junctions G01K7/02, G01K7/16, G01K7/30 take precedence
• CPC Class Codes: G05F 3/26 Current mirrors
• CPC Class Codes: G05F 3/265 using bipolar transistors only
• CPC Class Codes: G05F 3/267 using both bipolar and field-effect technology
• CPC Class Codes: G05F 3/30 Regulators using the difference between the base-emitter voltages of two bipolar transistors operating at different current densities G05F3/26 takes precedence
• CPC Class Codes: H03M 1/46 with digital/analogue converter for supplying reference values to converter

Abstract

A CMOS temperature sensor is provided. The CMOS temperature sensor, comprises: a bandgap reference circuit outputting a constant bandgap reference voltage regardless of temperature using a first voltage inversely proportional to temperature and a second voltage proportional to temperature and generating a first current proportional to temperature using the second voltage; a reference voltage generator copying the first current and outputting a reference voltage generated using the first voltage and the copied first current; and a temperature information voltage generator copying the first current and outputting a temperature information voltage proportional to temperature.

Claims

1. A CMOS temperature sensor, comprising:

a bandgap reference circuit providing a bandgap reference voltage regardless of temperature using a first voltage inversely proportional to temperature and a second voltage proportional to temperature, and further providing a first current proportional to temperature using the second voltage;

a reference voltage generator copying the first current and providing a reference voltage generated using the first voltage and the copied first current; and

a temperature information voltage generator copying the first current and providing a temperature information voltage proportional to temperature,

wherein the temperature information voltage generator includes a current source controlling a level of the temperature information voltage in response to the reference voltage.

2. The CMOS temperature sensor of claim 1, wherein the bandgap reference circuit includes a first BJT and a second BJT having commonly connected base terminals, and

the first voltage is a base-emitter voltage of the first BJT, and the second voltage is a difference between the first voltage and a base-emitter voltage of the second BJT.

3. The CMOS temperature sensor of claim 2, wherein the bandgap reference circuit comprises a first resistor connected to the second BJT, and the first current is a current flowing through the first resistor in response to the second voltage.

4. The CMOS temperature sensor of claim 1, wherein the current source controls the level of the temperature information voltage, such that the level of the temperature information voltage is not higher than a level of the reference voltage.

5. The CMOS temperature sensor of claim 1, wherein the bandgap reference circuit includes a first transistor and a second transistor having gates commonly connected at a node and equally dividing the first current.

6. The CMOS temperature sensor of claim 5, wherein the reference voltage generator and the temperature information voltage generator respectively receive a voltage level at the node, and respectively copy the first current using the voltage level at the node.

7. The CMOS temperature sensor of claim 5, wherein the reference voltage generator further includes a current source receiving a voltage level at the node and providing the first current.

8. The CMOS temperature sensor of claim 7, wherein the current source includes at least one transistor having a size different from a size of the first transistor.

9. The CMOS temperature sensor of claim 1, further comprising:

an analog-digital converter (ADC) receiving the reference voltage and the temperature information voltage, and performing an analog-to-digital conversion of the temperature information voltage to provide a temperature information signal.

10. The CMOS temperature sensor of claim 1, wherein the reference voltage is generated using the first voltage, the copied first current and a first resistance of a first resistor in the reference voltage generator, and

the temperature information voltage is generated by using the copied first current, the reference voltage, a second resistance of a second resistor in the current source and a third resistance of a third resistor in the temperature information voltage generator.

11. A CMOS temperature sensor, comprising:

a bandgap reference circuit providing a bandgap reference voltage regardless of temperature in relation to a first voltage inversely proportional to temperature and a second voltage proportional to temperature;

a reference voltage generator providing a reference voltage generated by correcting the first voltage into the second voltage; and

a temperature information voltage generator generating a temperature information voltage proportional to temperature on the basis of the second voltage.

12. The CMOS temperature sensor of claim 11, wherein the bandgap reference circuit includes a first BJT and a second BJT having commonly connected base terminals, and the first voltage is a base-emitter voltage of the first BJT, and the second voltage is a difference between the first voltage and a base-emitter voltage of the second BJT.

13. The CMOS temperature sensor of claim 11, wherein the temperature information voltage generator includes a current source controlling a level of the temperature information voltage in response to the reference voltage.

14. The CMOS temperature sensor of claim 13, wherein the current source controls the level of the temperature information voltage such that the level of the temperature information voltage is not higher than a level of the reference voltage.

15. The CMOS temperature sensor of claim 11, wherein the bandgap reference circuit includes a first transistor and a second transistor having gates commonly connected at a node.

16. The CMOS temperature sensor of claim 15, wherein the reference voltage generator and the temperature information voltage generator respectively receive a voltage level at the node in order to copy the first current.

17. The CMOS temperature sensor of claim 15, the reference voltage generator comprises a current source receiving a voltage level at the node and providing the first current.

18. The CMOS temperature sensor of claim 17, wherein the current source includes at least one transistor having size different from a size of the first transistor.

19. A CMOS temperature sensor, comprising:

a bandgap reference circuit including a first BJT and a second BJT whose base terminals are connected to each other, the bandgap reference circuit generating a temperature-proportional current using a first voltage, which is a base-emitter voltage of the first BJT, and a second voltage based on a difference between the first voltage and a base-emitter voltage of the second BJT;

a reference voltage generator generating a reference voltage on the basis of the temperature-proportional current and the first voltage; and

a temperature information voltage generator generating a temperature information voltage on the basis of the temperature-proportional current, and including a current source controlling a level of the temperature information voltage on the basis of the reference voltage.

20. The CMOS temperature sensor of claim 19, wherein the current source controls a level of the temperature information voltage, such that the level of the temperature information voltage is not higher than a level of the reference voltage.