Differential thermistor circuit

Patent metadata

Field	Value
Publication number	US-9772233-B2
Application number	US-201414272832-A
Country	US
Kind code	B2
Filing date	May 8, 2014
Priority date	Apr 19, 2010
Publication date	Sep 26, 2017
Grant date	Sep 26, 2017

Abstract

This document discusses, among other things, an apparatus and method for providing temperature information. In an example, an integrated circuit apparatus can include a first resistor configured to be coupled to a first terminal of a temperature-sensitive resistance, a second resistor configured to be coupled to a second terminal of the temperature-sensitive resistance, and a temperature information circuit configured to receive a first voltage from the first terminal of the temperature-sensitive resistance and a second voltage from the second terminal of the temperature-sensitive resistance. The temperature information circuit can provide the temperature information using the first and second voltages.

First claim

What is claimed is:

1. A method comprising:
receiving a first voltage from a first resistor coupled to a first terminal of a temperature-sensitive resistance at a temperature information circuit;
receiving a second voltage from a second resistor coupled to second terminal of the temperature-sensitive resistance at the temperature information circuit;
providing an output signal indicative of a difference between the first and second voltages; and
comparing the output signal to a reference voltage to provide an indication of temperature.

2. The method of claim 1 , wherein comparing the output signal to a reference voltage includes receiving the reference voltage from a reference resistor.

3. The method of claim 1 , wherein comparing the output signal to a reference voltage includes receiving the reference voltage from a reference diode.

4. The method of claim 1 , wherein a value of the first resistor substantially corresponds to a value of the second resistor.

5. The method of claim 1 , wherein the providing includes amplifying a difference between the first and second voltages using a differential amplifier of the temperature information circuit to provide temperature information.

6. The method of claim 1 , wherein the comparing includes comparing the output signal to a reference voltage using a comparator of the temperature information circuit to provide the indication of temperature.

7. The method of claim 1 , wherein the comparing the output signal to the reference voltage includes comparing an output signal of a differential amplifier of the temperature information circuit with the reference voltage.

8. The method of claim 7 , wherein comparing the output signal of a differential amplifier of the temperature information circuit to a reference voltage includes receiving the reference voltage from a reference resistor.

9. The method of claim 7 , wherein comparing the output signal of a differential amplifier of the temperature information circuit to a reference voltage includes receiving the reference voltage from a reference diode.

10. The method of claim 1 , including receiving the reference voltage from a reference generator of the temperature information circuit.

11. The method of claim 10 , wherein the reference generator includes a band-gap reference circuit.

12. The method of claim 10 , wherein the reference generator includes a diode based reference circuit.

13. The method of claim 10 , wherein the receiving the reference voltage includes applying a voltage across a voltage divider to provide the reference voltage.

14. The method of claim 13 , wherein applying the voltage includes applying the voltage across a voltage divider including an external resistance.

15. The method of claim 13 , wherein the applying the voltage includes applying the voltage across a voltage divider including a programmable resistance to provide a programmable reference voltage.

Assignees

• Fairchild Semiconductor

Inventors

• Snowdon Kenneth P
• Yarbrough Roy

Classifications

• G05D23/1906 Primary

  using an analogue comparing device · CPC title

• G05D23/24

  the sensing element having a resistance varying with temperature, e.g. a thermistor · CPC title

• G01K7/22 Primary

  the element being a non-linear resistance, e.g. thermistor (G01K7/26 takes precedence) · CPC title

• G01K7/24 Primary

  in a specially-adapted circuit, e.g. bridge circuit · CPC title

• H01C7/02

  having positive temperature coefficient · CPC title