Circuit apparatus, electronic apparatus, and moving object

Patent metadata

Field	Value
Publication number	US-10190918-B2
Application number	US-201615131183-A
Country	US
Kind code	B2
Filing date	Apr 18, 2016
Priority date	Apr 28, 2015
Publication date	Jan 29, 2019
Grant date	Jan 29, 2019

Abstract

A circuit apparatus includes a voltage output circuit that outputs a first output voltage when a first current of first temperature characteristics flows in a resistance element, and a second output voltage when a second current of second temperature characteristics different from the first temperature characteristics flows in the resistance element, an A/D conversion circuit that outputs a first digital value by performing A/D conversion on the first output voltage, and outputs a second digital value by performing A/D conversion on the second output voltage, and a processing unit that obtains temperature data by digital calculation processing of the first digital value and the second digital value.

First claim

What is claimed is:

1. A circuit apparatus comprising:
a voltage output circuit that outputs a first output voltage when a first current of first temperature characteristics flows in a resistance element, and a second output voltage when a second current of second temperature characteristics different from the first temperature characteristics flows in the resistance element, wherein the voltage output circuit includes
a first transistor configured to selectively provide the first current to the resistance element in a first period such that the voltage output circuit outputs the first output voltage in the first period, and
a second transistor configured to selectively provide the second current to the resistance element in a second period such that the voltage output circuit outputs the second output voltage in the second period;

an A/D conversion circuit that outputs a first digital value by performing A/D conversion on the first output voltage, and outputs a second digital value by performing A/D conversion on the second output voltage; and
a processing unit that obtains temperature data by digital calculation processing based on the first digital value and the second digital value.

2. The circuit apparatus according to claim 1 ,
wherein the processing unit performs the digital calculation processing that reduces dependence of the temperature data with respect to a resistance value of the resistance element.

3. The circuit apparatus according to claim 2 ,
wherein the processing unit obtains the temperature data by the digital calculation processing including division processing that divides the second digital value by the first digital value.

4. The circuit apparatus according to claim 1 ,
wherein the processing unit performs the digital calculation processing that reduces at least one variation of first variation of the temperature data by variation of a resistance value of the resistance element, and second variation of the temperature data by temperature characteristics of the resistance element.

5. The circuit apparatus according to claim 4 ,
wherein the processing unit obtains the temperature data by the digital calculation processing including division processing that divides the second digital value by the first digital value.

6. The circuit apparatus according to claim 1 ,
wherein the processing unit obtains the temperature data by the digital calculation processing including division processing that divides the second digital value by the first digital value.

7. The circuit apparatus according to claim 6 ,
wherein in a case where the first digital value is D REF , the second digital value is D PTAT , and a given constant is m, the processing unit performs processing that calculates, as the division processing, (D PTAT +m)/(D REF +m).

8. The circuit apparatus according to claim 1 , further comprising:
a first current generation circuit that generates the first current; and
a second current generation circuit that generates the second current,
wherein the voltage output circuit outputs a voltage, as the first output voltage, when the first current generated by the first current generation circuit flows in the resistance element, and outputs a voltage, as the second output voltage, when the second current generated by the second current generation circuit flows in the resistance element.

9. The circuit apparatus according to claim 1 ,
wherein the first current is a reference current with flat temperature characteristics, and
wherein the second current is a current having one of positive temperature characteristics and negative temperature characteristics.

10. The circuit apparatus according to claim 9 ,
wherein in a case where the second current has the positive temperature characteristics, the resistance element is a resistance element having the positive temperature characteristics, and in a case where the second current has the negative temperature characteristics, the resistance element is a resistance element having the negative temperature characteristics.

11. The circuit apparatus according to claim 9 ,
wherein the second current has the positive temperature characteristics, and
wherein the resistance element is a well resistance or a diffusion resistance.

12. The circuit apparatus according to claim 1 ,
wherein the processing unit performs digital low-pass filter processing with respect to the temperature data obtained by the digital calculation processing.

13. The circuit apparatus according to claim 12 ,
wherein the processing unit performs the digital low-pass filter processing where a cut-off frequency is varied with respect to the temperature data obtained by the digital calculation processing.

14. The circuit apparatus according to claim 13 ,
wherein the processing unit sets the cut-off frequency to a first frequency during a first period after starting, and sets the cut-off frequency to a second frequency lower than the first frequency during a second period after the first period has elapsed.

15. The circuit apparatus according to claim 1 ,
wherein the A/D conversion circuit is a differential A/D conversion circuit that receives a differential input signal configured with a first input signal and a second input signal,
wherein the voltage output circuit includes, as the resistance element, a first resistance element and a second resistance element, and
wherein the voltage output circuit outputs, as a voltage of the first input signal, an output voltage when the first current flows in the first resistance element to the A/D conversion circuit, and outputs, as a voltage of the second input signal, an output voltage when the first current flows in the second resistance element to the A/D conversion circuit, in a case where the first output voltage is output, and outputs, as a voltage of the first input signal, an output voltage when the second current flows in the first resistance element to the A/D conversion circuit, and outputs, as a voltage of the second input signal, an output voltage when the second current flows in the second resistance element to the A/D conversion circuit, in a case where the second output voltage is output.

16. The circuit apparatus according to claim 1 , further comprising:
a detection circuit that outputs physical quantity data corresponding to physical quantity based on a detection signal corresponding to the physical quantity output from a physical quantity transducer; and
a drive circuit that drives the physical quantity transducer,
wherein the processing unit performs correction processing based on the temperature data with respect to the physical quantity data from the detection circuit.

17. An electronic apparatus comprising:
the circuit apparatus according to claim 1 .

18. A moving object comprising:
the circuit apparatus according to claim 1 .

19. A circuit apparatus comprising:
a voltage output circuit that outputs a first output voltage when a first current of first temperature characteristics flows in a first resistance element and a second resistance element, and a second output voltage when a second current of second temperature characteristics different from the first temperature characteristics flows in the first resistance element and the second resistance element, wherein the voltage output circuit includes
a first transistor configured to selectively provide the first current to the first resistance element in a first period such that the voltage output circuit outputs the first output voltage in the first period,

Assignees

• Seiko Epson Corp

Inventors

• Higuchi Teppei
• Haneda Hideo

Classifications

• G01K1/20

  Compensating for effects of temperature changes other than those to be measured, e.g. changes in ambient temperature · CPC title

• G01K2219/00

  Thermometers with dedicated analog to digital converters · CPC title

• G01K13/00

  Thermometers specially adapted for specific purposes · CPC title

• G01K7/24

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

• G01K7/42

  Circuits effecting compensation of thermal inertia; Circuits for predicting the stationary value of a temperature · CPC title