Oscillator, electronic apparatus, and moving object

• US 9,537,448 B2
• Filed: 02/02/2016
• Issued: 01/03/2017
• Est. Priority Date: 02/04/2015
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Fukuzawa, Akihiro
• Primary Examiner(s): Gannon, Levi
• Application Number:
  US15/013,160
• Publication Number:
  US 20160226446A1
• Time in Patent Office: 336 Days
• Field of Search: 331/36.C, 331/44, 331/105, 331/154, 331/158, 331/175, 331/177.V, 332/124
• US Class Current: 1/1
• CPC Class Codes: H03B 2200/0092 Measures to linearise or reduce distortion of oscillator characteristics
• CPC Class Codes: H03B 2201/0266 the means comprising a transistor
• CPC Class Codes: H03B 5/124 the means comprising a voltage dependent capacitance
• CPC Class Codes: H03B 5/32 being a piezoelectric resonator selection of piezoelectric material H10N30/00
• CPC Class Codes: H03B 5/366 and comprising means for varying the frequency by a variable voltage or current
• CPC Class Codes: H03L 2207/05 Compensating for non-linear characteristics of the controlled oscillator

Abstract

An oscillator includes: an oscillation circuit whose oscillation frequency changes based on a voltage that is applied to a variable capacitance element; and a voltage generation unit that generates the voltage which is applied to the variable capacitance element based on a control signal, in which the voltage that is generated by the voltage generation unit changes nonlinearly with respect to a change in the control signal such that a change in the oscillation frequency with respect to the change in the control signal is adjusted to come close to be linear.

Claims

1. An oscillator comprising:

an oscillation circuit that includes a variable capacitance element and whose oscillation frequency changes based on a voltage that is applied to the variable capacitance element; and

a voltage generation unit that generates the voltage which is applied to the variable capacitance element based on a control signal, wherein the voltage generation unit includes a D/A conversion circuit and the control signal is a digital signal,

wherein the voltage that is generated by the voltage generation unit changes nonlinearly with respect to a change in the control signal such that a change in the oscillation frequency with respect to the change in the control signal is adjusted to come close to being linear.

2. The oscillator according to claim 1,

wherein an output voltage of the D/A conversion circuit changes nonlinearly with respect to a change in an input signal.

3. An electronic apparatus comprising:

the oscillator according to claim 2.

4. A moving object comprising:

the oscillator according to claim 2.

5. The oscillator according to claim 1,

wherein an output voltage of the D/A conversion circuit changes linearly with respect to a change in an input signal, and

wherein the voltage generation unit includes a signal conversion unit that converts the control signal into a signal that changes nonlinearly with respect to the change in the control signal and outputs the signal to the D/A conversion circuit.

6. The oscillator according to claim 5,

wherein the signal conversion unit converts the control signal into the signal that changes nonlinear, using a lookup table.

7. An electronic apparatus comprising:

the oscillator according to claim 6.

8. A moving object comprising:

the oscillator according to claim 6.

9. An electronic apparatus comprising:

the oscillator according to claim 5.

10. A moving object comprising:

the oscillator according to claim 5.

11. An electronic apparatus comprising:

the oscillator according to claim 1.

12. A moving object comprising:

the oscillator according to claim 1.

13. An oscillator comprising:

an oscillation circuit that includes a variable capacitance element and whose oscillation frequency changes based on a voltage that is applied to the variable capacitance element; and

a voltage generation unit that generates the voltage which is applied to the variable capacitance element based on a control signal, wherein;

the control signal is an analog signal, and

the voltage generation unit includes

an A/D conversion circuit that converts the control signal into a digital signal, and

a D/A conversion circuit that converts the digital signal converted by the A/D conversion circuit into the voltage that is applied to the variable capacitance element,

wherein the A/D conversion circuit converts the control signal into the digital signal that changes nonlinearly with respect to the change in the control signal.

14. An electronic apparatus comprising:

the oscillator according to claim 13.

15. A moving object comprising:

the oscillator according to claim 13.

16. An oscillator comprising:

an oscillation circuit that includes a variable capacitance element and whose oscillation frequency changes based on a voltage that is applied to the variable capacitance element; and

a voltage generation unit that generates the voltage which is applied to the variable capacitance element based on a control signal, wherein;

the control signal is an analog signal,

the voltage generation unit includes

an A/D conversion circuit that converts the control signal into a digital signal, and

a D/A conversion circuit that converts the digital signal converted by the A/D conversion circuit into the voltage that is applied to the variable capacitance element, and

wherein the D/A conversion circuit converts the digital signal converted by the A/D conversion circuit into the voltage that changes nonlinearly with respect to the change in the digital signal.