Temperature detection circuit

• US 20060056486A1
• Filed: 08/23/2005
• Published: 03/16/2006
• Est. Priority Date: 09/14/2004
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: NEC Electronics Corporation (Renesas Electronics Corporation)
• Inventors: Mikuni, Takeshi, Tamagawa, Akio
• Granted Patent: US 7,350,974 B2
• Time in Patent Office: Days
• US Class Current: 374/178
• CPC Class Codes: G01K 7/01 using semiconducting elements having PN junctions G01K7/02, G01K7/16, G01K7/30 take precedence

Abstract

A temperature detection circuit according to the present invention includes a potential generating part and a temperature detection part. The potential generating part generates a potential according to an environmental temperature, and the temperature detection part detects a temperature based on a detection potential generated in the potential generated part. The temperature detection part is a resistive load type inverter circuit that outputs a detection signal when the generated potential reaches a threshold voltage. The potential generating part applies the detection potential to the inverter circuit through a temperature sensor including cascaded diodes and an NchMOSFET. The threshold voltage of the inverter circuit is determined based on the NchMOSFET in the inverter circuit, and the NchMOSFET is a MOSFET having the same characteristic as the NchMOSFET of the potential generating part.

Claims

1. A temperature detection circuit, comprising:

a potential generating part generating a potential corresponding to a detection temperature; and

a temperature detection part detecting a temperature based on a generated potential in the potential generating part,

wherein the temperature detection part includes a detection device composed of a semiconductor device detecting a temperature based on the generated potential, and

the potential generating part includes a semiconductor device having substantially the same characteristic as the detection device.

2. The temperature detection circuit according to claim 1, wherein the potential generating part includes a constant current circuit and a temperature sensor supplied with a constant current from the constant current circuit, and the temperature sensor includes the semiconductor device.

3. The temperature detection circuit according to claim 1, wherein the potential generating part includes a constant current circuit, a diode supplied with a constant current from the constant current circuit, and a transistor series-connected with the diode, and the temperature detection part is an inverter circuit including the detection device.

4. The temperature detection circuit according to claim 1, wherein the temperature detection part is a resistive load type inverter circuit.

5. The temperature detection circuit according to claim 1, wherein the temperature detection part is a constant-current load type inverter circuit.

6. A temperature detection circuit, comprising:

a potential generating part including a constant current circuit, and a temperature sensor supplied with a constant current from the constant current circuit, and generating a potential corresponding to a detection temperature; and

a temperature detection part detecting a temperature based on a generated potential in the potential generating part,

wherein the temperature detection part includes a detection device composed of a semiconductor device detecting a temperature based on the generated potential, and

the potential generating part includes a semiconductor device having substantially the same characteristic as the detection device.

7. The temperature detection circuit according to claim 6, wherein the semiconductor devices included in the potential generating part and in the temperature detection part are transistors of substantially the same threshold characteristics.

8. The temperature detection circuit according to claim 6, wherein the temperature sensor includes cascaded diodes, and a transistor connected with the cascaded diodes, as the detection device.

9. The temperature detection circuit according to claim 6, wherein the potential generating part includes a constant current circuit, a diode supplied with a constant current from the constant current circuit, and a transistor series-connected with the diode as the semiconductor device, and the temperature detection part is an inverter circuit including a transistor as the detection device.

10. The temperature detection circuit according to claim 6, wherein the temperature detection part is a resistive load type inverter circuit.

11. The temperature detection circuit according to claim 6, wherein the temperature detection part is a constant-current load type inverter circuit.

12. The temperature detection circuit according to claim 7, wherein the transistors are N-channel MOSFETs.

13. The temperature detection circuit according to claim 7, wherein the transistors are manufactured based on the same design.

14. The temperature detection circuit according to claim 7, wherein the transistors are manufactured through the same process.