CIRCUIT DEVICE, OSCILLATOR, ELECTRONIC APPARATUS, VEHICLE, AND MANUFACTURING METHOD FOR CIRCUIT DEVICE

• US 20180241344A1
• Filed: 02/20/2018
• Published: 08/23/2018
• Est. Priority Date: 02/23/2017
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: KIYOHARA, Atsushi, KANO, Shinnosuke, ISOZAKI, Shigenori, NONOYAMA, Mihiro
• Granted Patent: US 10,461,694 B2
• Time in Patent Office: Days
• CPC Class Codes: H03B 5/04 Modifications of generator to compensate for variations in physical values, e.g. power supply, load, temperature
• CPC Class Codes: H03B 5/32 being a piezoelectric resonator selection of piezoelectric material H10N30/00
• CPC Class Codes: H03L 1/02 against variations of temperature only
• CPC Class Codes: H03L 7/00 Automatic control of frequency or phase; Synchronisation
• CPC Class Codes: H03M 1/12 Analogue/digital converters H03M1/001 – H03M1/10 take precedence

Abstract

A circuit device includes an A/D conversion circuit that performs A/D conversion on a temperature detection voltage from a temperature sensor so as to output temperature detection data, and a digital signal processing circuit that performs a temperature compensation process on the basis of the temperature detection data, in which the A/D conversion circuit operates in a first mode, and switches to a second mode in a case where a predetermined condition is established.

Claims

1. A circuit device comprising:

an A/D conversion circuit configured to perform A/D conversion on a temperature detection voltage from a temperature sensor so as to output temperature detection data; and

a digital signal processing circuit configured to perform a temperature compensation process based on the temperature detection data,

wherein the A/D conversion circuit

operates in a first mode so as to obtain the temperature detection data by performing an A/D conversion process according to a first A/D conversion method, and

switches to a second mode so as to obtain the temperature detection data by performing an A/D conversion process according to a second A/D conversion method which is different from the first A/D conversion method in a case where a predetermined condition is established.

2. The circuit device according to claim 1,

wherein, in a case where the minimum resolution of data in A/D conversion is indicated by LSB, the first A/D conversion method is a process of obtaining the temperature detection data such that a change in the temperature detection data at a second output timing following a first output timing with respect to the temperature detection data at the first output timing is equal to or less than k×

LSB (where k is a positive integer satisfying k<

j; and

j is a positive integer representing a resolution in A/D conversion).

3. The circuit device according to claim 1,

wherein the A/D conversion circuit includes

a register portion in which intermediate result data or final result data is stored as result data,

a D/A converter that performs D/A conversion on the result data so as to output a D/A conversion voltage,

a comparison circuit that compares the temperature detection voltage from the temperature sensor with the D/A conversion voltage from the D/A converter, and

a processing circuit that performs a determination process on the basis of a comparison result in the comparison circuit, and performs an update process of the result data on the basis of the determination process,

wherein the processing circuit outputs the final result data which is a result of the update process as the temperature detection data.

4. The circuit device according to claim 3,

wherein the second A/D conversion method is a process in which the determination process is performed on an MSB side of the result data in a first determination period, and the determination process on an LSB side of the result data is performed in a second determination period which is longer than the first determination period.

5. The circuit device according to claim 1, further comprising:

an interface; and

a storage unit to which circuit constant setting information of the circuit device is written via the interface,

wherein the A/D conversion circuit switches to the second mode in a case where the circuit constant setting information is written via the interface.

6. The circuit device according to claim 5,

wherein the circuit constant setting information is at least one of reference voltage adjustment information, reference current adjustment information, and oscillation frequency adjustment information.

7. The circuit device according to claim 1, further comprising:

an interface,

wherein the A/D conversion circuit switches to the second mode in a case where a command for switching to the second mode is input via the interface.

8. The circuit device according to claim 5,

wherein the A/D conversion circuit switches to the second mode on the basis of a switching signal from the interface.

9. The circuit device according to claim 1,

wherein the A/D conversion circuit includes a temperature change detection circuit, and switches to the second mode in a case where a predetermined temperature change is detected by the temperature change detection circuit.

10. The circuit device according to claim 1,

wherein the A/D conversion circuit switches to the second mode in a case where the predetermined condition is established, and switches to the first mode after the temperature detection data which is an A/D conversion result in the second mode is output.

11. The circuit device according to claim 1,

wherein the A/D conversion circuit

operates in the second mode in an activation period, and switches to the first mode after the temperature detection data which is an A/D conversion result in the second mode is output, and

switches to the second mode in a case where the predetermined condition is established after switching to the first mode occurs.

12. The circuit device according to claim 1, further comprising:

an oscillation signal generation circuit

wherein the digital signal processing circuit performs a temperature compensation process on an oscillation frequency from the oscillation signal generation circuit on the basis of the temperature detection data, and outputs frequency control data of the oscillation frequency, and

wherein the oscillation signal generation circuit generates an oscillation signal with the oscillation frequency set by the frequency control data by using the frequency control data from the digital signal processing circuit and a resonator.

13. An oscillator comprising:

the circuit device according to claim 12; and

the resonator.

14. An electronic apparatus comprising the circuit device according to claim 1.

15. An electronic apparatus comprising the circuit device according to claim 2.

16. An electronic apparatus comprising the circuit device according to claim 3.

17. A vehicle comprising the circuit device according to claim 1.

18. A vehicle comprising the circuit device according to claim 2.

19. A vehicle comprising the circuit device according to claim 3.

20. A manufacturing method for a circuit device which performs A/D conversion on a temperature detection voltage from a temperature sensor, so as to output temperature detection data, and includes an A/D conversion circuit, a storage unit, and an interface, the method comprising:

performing measurement for determining circuit constant setting information; and

causing an operation of the A/D conversion circuit to switch from a first mode in which an A/D conversion process is performed according to a first A/D conversion method in order to obtain the temperature detection data to a second mode in which an A/D conversion process is performed according to a second A/D conversion method which is different from the first A/D conversion method in order to obtain the temperature detection data, when the circuit constant setting information is written to the storage unit via the interface on the basis of a result of the measurement.