Oscillation circuit, oscillator, method of manufacturing oscillator, electronic device, and moving object

Patent metadata

Field	Value
Publication number	US-9628022-B2
Application number	US-201414527123-A
Country	US
Kind code	B2
Filing date	Oct 29, 2014
Priority date	Oct 30, 2013
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

An oscillation circuit includes a terminal XO, a terminal XI, an oscillation unit, and a voltage generation circuit that generates a first voltage and a second voltage. The oscillation unit includes a variable capacitive element connected to the terminal XO or the terminal XI. In a first mode, a signal having a first amplitude is applied between the terminal XO and the terminal XI, and a first voltage is applied to the other end of the variable capacitive element. In a second mode, a signal having a second amplitude larger than an amplitude of the signal having the first amplitude is applied between the terminal XO and the terminal XI, a second voltage is applied to the other end of the variable capacitive element, and a voltage applied to the both ends of the variable capacitive element is lower than the maximum rated voltage of the variable capacitive element.

First claim

What is claimed is:

1. An oscillation circuit comprising:
a first terminal which is connected to one end of a resonator;
a second terminal which is connected to the other end of the resonator;
an oscillation unit which is electrically connected to the first terminal and the second terminal, wherein the oscillation unit includes at least one first electronic element of which a first end of the first electronic element is electrically connected to the first terminal or the second terminal, and the oscillation unit is operable in a normal mode or a test mode;
a first voltage generation circuit that includes a control voltage generation circuit and an overdrive voltage generation circuit, wherein the control voltage generation circuit generates a control voltage signal based on a temperature, the overdrive voltage generation circuit generates an overdrive voltage signal that has a voltage value less than the maximum rated voltage of the first electronic element and greater than a voltage outputted by the control voltage generation circuit, and an amplitude of the control voltage signal is less than that of the overdrive voltage signal; and
a first switching unit configured to electrically couple and decouple the oscillation unit to one of the control voltage generation circuit and the overdrive voltage generation circuit based on an operation mode of the oscillation unit, wherein the first switching unit is connected to a second end of the first electronic element,
wherein, in the normal mode, the first switching unit connects the second end of the first electronic element to the control voltage generation circuit to apply the control voltage signal based on the temperature to the first terminal and the second terminal by way of the first electronic element,
wherein, in the test mode, the first switching unit connects the second end of the first electronic element to the overdrive voltage generation circuit to apply, to the first terminal and the second terminal by way of the first electronic element, the overdrive voltage signal having the voltage value less than the maximum rated voltage of the first electronic element and greater than the voltage outputted by the control voltage generation circuit,
wherein the at least one first electronic element includes two first electronic elements, wherein one of the first electronic elements has the first end connected to the first terminal and the other one of the first electronic elements has the first end connected to the second terminal, and
wherein the overdrive voltage signal from the overdrive voltage generation circuit satisfies the following condition in which Vod is the voltage of the overdrive voltage signal, Vop1 is a maximum rated voltage of the one of the first electronic elements, Vmin is a minimum voltage value applied to the first end of the one of the first electronic elements by way of the first terminal, Vop2 is a maximum rated voltage of the other one of the first electronic elements, and Vmax is a maximum voltage value applied to the first end of the other one of the first electronic elements by way of the second terminal:
V op1 >|V od− V min| and V op2 >|V max− V od|.

2. The oscillation circuit according to claim 1 , wherein the first electronic elements are variable capacitive element.

3. The oscillation circuit according to claim 1 , further comprising a second voltage generation circuit that generates a third voltage,
wherein the voltage value of the control voltage signal is provided as a first voltage and the voltage value of the overdrive voltage signal is provided as a second voltage,
wherein the oscillation unit further includes at least one second electronic element of which one end is connected to the first terminal or the second terminal,
wherein the third voltage is applied to the other end of the second electronic element in the normal mode,
wherein the second voltage is applied to the other end of the second electronic element in the test mode, and
wherein a voltage applied to the both ends of the second electronic element in the test mode is lower than the maximum rated voltage of the second electronic element.

4. The oscillation circuit according to claim 3 , wherein the second electronic element is a variable capacitive element.

5. The oscillation circuit according to claim 1 , further comprising:
a third terminal; and
a fourth terminal which is connected to the second terminal,
wherein the first switching unit is controlled so that the first terminal and the third terminal are electrically separated from each other in the normal mode, and is controlled so that the first terminal and the third terminal are electrically connected to each other in the test mode.

6. The oscillation circuit according to claim 5 , wherein the third terminal is grounded.

7. The oscillation circuit according to claim 5 , further comprising a second switching unit,
wherein the second switching unit is controlled so that the second terminal and the fourth terminal are electrically separated from each other in the normal mode, and is controlled so that the second terminal and the fourth terminal are electrically connected to each other in the test mode.

8. The oscillation circuit according to claim 1 , wherein the first terminal is connected to an input terminal side of the oscillation unit.

9. The oscillation circuit according to claim 1 , wherein switching between the normal mode and the test mode is performed on the basis of a clock signal which is input during a period in which a power supply voltage is equal to or greater than a reference value.

10. An oscillator comprising:
the oscillation circuit according to claim 1 ; and
a resonator.

11. The oscillator according to claim 10 , further comprising a package that accommodates the oscillation circuit and the resonator.

12. An electronic device comprising the oscillation circuit according to claim 1 .

13. A moving object comprising the oscillation circuit according to claim 1 .

Assignees

• Seiko Epson Corp

Inventors

• Itasaka Yosuke
• Ishikawa Masayuki
• Yamamoto Takehiro
• Fukuzawa Akihiro

Classifications

• H03B5/368

  the means being voltage variable capacitance diodes · CPC title

• H03B5/362

  the amplifier being a single transistor (H03B5/364 - H03B5/368 take precedence) · CPC title

• H03B5/1231

  the amplifier comprising one or more bipolar transistors · CPC title

• Y10T29/42

  Piezoelectric device making · CPC title

• H03B5/04

  Modifications of generator to compensate for variations in physical values, e.g. power supply, load, temperature · CPC title