JP2010130142A - Voltage-controlled piezoelectric oscillator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To widen the adjustment range of the oscillation frequency of a voltage-controlled piezoelectric oscillator. <P>SOLUTION: The voltage-controlled piezoelectric oscillator 100 includes: a piezoelectric vibrator 100, including a first terminal P1 and a second terminal P2; an oscillation circuit 200, including varactors VC1 and VC2 whose electrostatic capacity is changed by a control voltage Vc applied from the outside, and a third terminal P3 and a fourth terminal P4, and for oscillating the piezoelectric vibrator 100 and outputting the oscillation signals of a prescribed frequency; a package 10 including the piezoelectric vibrator and the oscillation circuit 200; a first switching part 310, which is connected between the first terminal P1 and the third terminal P3, capable of changing the capacitance value and inductance value of wiring, and is formed on the package 10; and a second switching part 320, which is connected in between the second terminal P2 and the fourth terminal P4, capable of changing the capacitance value and inductance value of wiring, and is formed on the package 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a voltage controlled piezoelectric oscillator capable of changing an oscillation frequency.

  A voltage controlled piezoelectric oscillator (VCXO) is an oscillator that can adjust a small amount of frequency by changing a control voltage. However, in order to match the specifications of the customer's electronic equipment incorporating the VCXO, it may not be possible to adjust by a small amount of frequency adjustment using the control voltage.

  In order to solve this problem, for example, Patent Document 1 describes a method of expanding a frequency adjustment amount by incorporating two crystal resonators having different characteristics into a voltage-controlled piezoelectric oscillator and switching between them. However, since two crystal resonators are incorporated, there is a problem that the package size is increased, and further, the matching of the characteristics of the crystal resonator is complicated.

  In order to solve this problem, for example, Patent Document 2 describes a method of preparing three series circuits of a crystal resonator, a variable coil, and a variable capacitance diode and switching them.

JP 63-260304 A Japanese Utility Model Publication No. 56-17711

  However, in the conventional method, it is difficult to design a combination of a series circuit of a crystal resonator, a variable coil, and a variable capacitance diode, and there is a problem that the package size becomes large.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
A piezoelectric vibrator including a first terminal and a second terminal; a variable capacitance element whose capacitance is changed by a control voltage applied from the outside; a third terminal; and a fourth terminal. An oscillation circuit that oscillates and outputs an oscillation signal of a predetermined frequency, a package including the piezoelectric vibrator and the oscillation circuit, and a capacitance value of a wiring connected between the first terminal and the third terminal And the first switching unit formed on the package capable of changing the inductance value, and the capacitance value and the inductance value of the wiring connected between the second terminal and the fourth terminal can be changed. And a second switching portion formed on the package.

  According to this configuration, the capacitance value and inductance value of the wiring from the oscillation circuit to the piezoelectric vibrator can be changed by a combination of switching between the first switching unit and the second switching unit, so that the frequency can be adjusted flexibly. Further, since the first switching unit and the second switching unit are formed on the package, the package size can be suppressed.

[Application Example 2]
In the voltage controlled piezoelectric oscillator described above, the first switching unit includes a fifth terminal connected to the first terminal, a fifth + K terminal (N is an integer equal to or greater than 1, and K is 1 ≦ K). ≦ N, all integers), and K-th wirings having different capacitance values and inductance values for connecting the fifth terminal and the fifth + K terminal, and the second switching unit includes the second switching unit, A 6 + N terminal connected to the second terminal, a 6 + N + L terminal (M is an integer equal to or greater than 1 and L is an integer of 1 ≦ L ≦ M), the 6 + N terminal, and the 6 + N + L terminal N + L wirings having different capacitance values and inductance values for connecting the terminals, the third terminal and the fifth + K terminal are connected by bonding, and the fourth terminal and the fourth terminal are connected. Bonding with any of 6 + N + L terminals Voltage controlled piezoelectric oscillator, wherein the connection to it.

  According to this configuration, the capacitance value and inductance value of the wiring from the oscillation circuit to the piezoelectric vibrator can be changed by the bonding combination of the terminals of the oscillation circuit and the first switching unit and the second switching unit. The frequency can be adjusted flexibly after delivery first, and the first switching unit and the second switching unit are formed on the package, so that the package size can be suppressed.

  Hereinafter, embodiments of a voltage-controlled piezoelectric oscillator will be described with reference to the drawings.

(First embodiment)
<Configuration of voltage controlled piezoelectric oscillator>
First, the configuration of the voltage controlled piezoelectric oscillator according to the first embodiment will be described with reference to FIG. FIG. 1 is a configuration diagram illustrating the configuration of the voltage controlled piezoelectric oscillator according to the first embodiment.

  As shown in FIG. 1, a voltage controlled piezoelectric oscillator 1 includes a piezoelectric vibrator 100, an oscillation circuit 200, a first switching unit 310, and a second switching unit on a package 10 made of a ceramic material or the like. 320 is mounted and configured.

  The piezoelectric vibrator 100 includes a vibrator 110 connected to the first terminal P1 and the second terminal P2.

  The oscillation circuit 200 includes two variable capacitance elements VC1, VC2, three resistors R1, R2, R3, an inverter IN1, a third terminal P3, a fourth terminal P4, and a control voltage from the outside. And a control voltage terminal Vc to be applied. The variable capacitor VC1 is connected between the third terminal P3 and the ground potential line GND, and is connected to the control voltage terminal Vc through the resistor R1. The variable capacitor VC2 is connected between the fourth terminal P4 and the ground potential line GND, and is connected to the control voltage terminal Vc through the resistor R2. The inverter IN1 is connected between the third terminal P3 and the fourth terminal P4. The resistor R3 is connected between the third terminal P3 and the fourth terminal P4.

  The first switching unit 310 connects the fifth terminal P5, the sixth terminal P6, the seventh terminal P7 (when N = 2), and the fifth terminal P5 and the sixth terminal P6. And a second wiring 312 connecting the fifth terminal P5 and the seventh terminal P7. The first wiring 311 and the second wiring 312 have different wiring lengths and different wiring capacitance values and inductance values.

  The second switching unit 320 connects the eighth terminal P8, the ninth terminal P9, the tenth terminal P10 (when M = 2), and the eighth terminal P8 and the ninth terminal P9. The third wiring 321 and the fourth wiring 322 connecting the eighth terminal P8 and the tenth terminal P10. The third wiring 321 and the fourth wiring 322 have different wiring lengths and different wiring capacitance values and inductance values.

  The first terminal P 1 of the piezoelectric vibrator 100 and the fifth terminal P 5 of the first switching unit 310 are connected by the wiring material 101. The second terminal P <b> 2 of the piezoelectric vibrator 100 and the eighth terminal P <b> 8 of the second switching unit 320 are connected by the wiring member 102.

  The third terminal P3 of the oscillation circuit 200 is connected to either the sixth terminal P6 or the seventh terminal P7 of the first switching unit 310 by a bonding wire 301. The fourth terminal P4 of the oscillation circuit 200 is connected to either the ninth terminal P9 or the tenth terminal P10 of the second switching unit 320 by a bonding wire 302.

  FIG. 2 is an equivalent circuit diagram of the first switching unit 310 and the second switching unit 320 of the voltage controlled piezoelectric oscillator 1.

  As shown in FIG. 2, the first wiring 311 of the first switching unit 310 can be represented by an inductance La1 and two capacitors Ca11 and Ca12. The second wiring 312 of the first switching unit 310 can be represented by an inductance La2 and two capacitors Ca21 and Ca22. As shown in FIG. 1, since the wiring length of the first wiring 311 <the wiring length of the second wiring 312, the inductance value of the inductance La1 <the inductance value of the inductance La2, the capacitance value of the capacitors Ca11 and Ca12 <the capacitors Ca21 and Ca22. Capacity value.

  The third wiring 321 of the second switching unit 320 can be represented by an inductance Lb1 and two capacitors Cb11 and Cb12. The fourth wiring 322 of the second switching unit 320 can be represented by an inductance Lb2 and two capacitors Cb21 and Cb22. As shown in FIG. 1, since the wiring length of the third wiring 321 <the wiring length of the fourth wiring 322, the inductance value of the inductance Lb1 <the inductance value of the inductance Lb2, the capacitance value of the capacitors Cb11, Cb12 <the capacitors Cb21, Cb22 Capacity value.

  As shown in FIG. 2, the inductance La1 is connected between the first terminal P1 and the third terminal P3 by connecting the third terminal P3 and the sixth terminal P6 with a bonding wire 301. The value and the capacitance value of the capacitors Ca11 and Ca12 are added. Further, by connecting the fourth terminal P4 and the tenth terminal P10 with the bonding wire 302, the inductance value of the inductance Lb2 and the capacitor Cb21, between the second terminal P2 and the fourth terminal P4, A capacitance value of Cb22 is added.

  There are two methods for connecting the bonding wire 301, that is, between the third terminal P3 and the sixth terminal P6 and between the third terminal P3 and the seventh terminal P7. Since there are two types of terminal P4 to the ninth terminal P9 and between the fourth terminal P4 to the tenth terminal P10, there are a total of four combinations between the first terminal P1 and the third terminal P3. It is possible to switch between the inductance value and the capacitance value and the inductance value and the capacitance value between the second terminal P2 and the fourth terminal P4.

  FIG. 3 is a top view illustrating an example of a wiring method of the first switching unit 310 and the second switching unit 320 on the package 10 of the voltage controlled piezoelectric oscillator 1.

  As shown in FIG. 3, on the package 10, a fifth terminal P5, a sixth terminal P6, a seventh terminal P7, a first wiring 311 and a second wiring constituting the first switching unit 310 are provided. 312 and an eighth terminal P8, a ninth terminal P9, a tenth terminal P10, a third wiring 321 and a fourth wiring 322 constituting the second switching unit 320 are formed. The oscillation circuit 200 is bonded to the bottom of the package 10. The piezoelectric vibrator 100 is placed on the top of the package 10, the first terminal P1 and the fifth terminal P5 are connected by the wiring material 101 (black circle portion), and the second terminal P2 and the eighth terminal. P8 is connected to the wiring member 102 (black circle portion).

  In FIG. 3, the third terminal P3 and the sixth terminal P6 of the oscillation circuit 200 are connected by the bonding wire 301, and the fourth terminal P4 and the tenth terminal P10 of the oscillation circuit 200 are connected by the bonding wire 302. The state that has been done.

  According to the present embodiment described above, the following effects can be obtained.

  In the present embodiment, the capacitance value and the inductance value of the wiring from the oscillation circuit 200 to the piezoelectric vibrator 100 are changed by the bonding combination of the terminals of the oscillation circuit 200 and the first switching unit 310 and the second switching unit 320. Therefore, the frequency can be adjusted flexibly even after delivery to the customer, and the package size can be reduced because the first switching unit 310 and the second switching unit 320 are formed on the package 10.

  The embodiments of the voltage controlled piezoelectric oscillator have been described above. However, the embodiments are not limited to these embodiments, and can be implemented in various forms without departing from the spirit of the present invention. Hereinafter, a modification will be described.

  (Modification 1) Modification 1 of the voltage controlled piezoelectric oscillator will be described. In the first embodiment, as the first switching unit 310, the fifth terminal P5, the sixth terminal P6, the seventh terminal P7, the first wiring 311 and the second wiring 312 (when N = 2). The case of the eighth terminal P8, the ninth terminal P9, the tenth terminal P10, the third wiring 321 and the fourth wiring 322 (when M = 2) has been described as the second switching unit 320. However, other combinations (one or more of N and M) may be used.

  FIG. 4 is a configuration diagram illustrating a configuration of the voltage controlled piezoelectric oscillator according to the first modification. As shown in FIG. 4, the voltage controlled piezoelectric oscillator 4 connects the first wiring 411 that connects the fifth terminal P5 and the sixth terminal P6, and the fifth terminal P5 and the seventh terminal P7. A first switching unit 410 composed of a second wiring 412 to be connected, a third wiring 413 (in the case of N = 3) for connecting the fifth terminal P5 and the eighth terminal P8, The fourth wiring 421 connecting the ninth terminal P9 and the tenth terminal P10, the fifth wiring 422 connecting the ninth terminal P9 and the eleventh terminal P11, the ninth terminal P9 and the ninth terminal P9. The second switching unit 420 is configured to include a sixth wiring 423 (when M = 3) that connects the twelve terminals P12.

  According to this configuration, the first terminal P <b> 1-the third terminal P <b> 3 with nine combinations including the three wiring methods of the first switching unit 410 and the three wiring methods of the second switching unit 420. The inductance value and capacitance value between the second terminal P2 and the fourth terminal P4 can be switched, and the frequency can be adjusted more flexibly.

  (Modification 2) Modification 2 of the voltage controlled piezoelectric oscillator will be described. In the first modification, the first switching unit 410 and the second switching unit 420 as illustrated in FIG. 4 are described, but another wiring method may be used.

  FIG. 5 is a configuration diagram showing the configuration of the voltage controlled piezoelectric oscillator according to the second modification. As shown in FIG. 5, the voltage controlled piezoelectric oscillator 5 connects the first wiring 511 connecting the fifth terminal P5 and the sixth terminal P6, and the sixth terminal P6 and the seventh terminal P7. A first switching unit 510, a ninth terminal P9, and a tenth wiring line 513, and a third wiring line 513 connecting the seventh terminal P7 and the eighth terminal P8. The fourth wiring 521 connecting the terminal P10, the fifth wiring 522 connecting the tenth terminal P10 and the eleventh terminal P11, and the eleventh terminal P11 and the twelfth terminal P12. And a second switching unit 520 configured from the sixth wiring 523.

  According to this configuration, the first switching unit 510 and the second switching unit 520 can make the wiring length shorter than the first switching unit 410 and the second switching unit 420 of the first modification. Package size can be reduced.

The block diagram which shows the structure of the voltage control piezoelectric oscillator which concerns on 1st Embodiment. The equivalent circuit diagram of the 1st switching part and 2nd switching part of a voltage control piezoelectric oscillator. The top view which shows an example of the wiring method of the 1st switching part and the 2nd switching part on the package of a voltage control piezoelectric oscillator. FIG. 6 is a configuration diagram showing a configuration of a voltage controlled piezoelectric oscillator according to a first modification. FIG. 9 is a configuration diagram showing a configuration of a voltage controlled piezoelectric oscillator according to a second modification.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,4,5 ... Voltage controlled piezoelectric oscillator, 10 ... Package, 100 ... Piezoelectric vibrator, 101, 102 ... Wiring material, 110 ... Vibrator, 200 ... Oscillator circuit, 301, 302 ... Bonding wire, 310 ... First Switching unit, 311 ... first wiring, 312 ... second wiring, 320 ... second switching unit, 321 ... third wiring, 322 ... fourth wiring, 410 ... first switching unit, 411 ... first 1 wiring, 412 ... 2nd wiring, 413 ... 3rd wiring, 420 ... 2nd switching part, 421 ... 4th wiring, 422 ... 5th wiring, 423 ... 6th wiring, 510 ... 5th. 1 switching unit, 511... 1st wiring, 512... 2nd wiring, 513... 3rd wiring, 520... 2nd switching unit, 521... 4th wiring, 522. 6th wiring.

Claims (2)

A piezoelectric vibrator including a first terminal and a second terminal;
An oscillation circuit including a variable capacitance element whose capacitance is changed by a control voltage applied from the outside, a third terminal, and a fourth terminal, and oscillating the piezoelectric vibrator and outputting an oscillation signal of a predetermined frequency;
A package including the piezoelectric vibrator and the oscillation circuit;
A first switching unit connected between the first terminal and the third terminal and formed on the package capable of changing a capacitance value and an inductance value of a wiring;
A second switching unit formed on the package connected between the second terminal and the fourth terminal and capable of changing a capacitance value and an inductance value of a wiring;
including,
A voltage-controlled piezoelectric oscillator. The voltage controlled piezoelectric oscillator according to claim 1.
The first switching unit includes a fifth terminal connected to the first terminal, a fifth + K terminal (N is an integer equal to or greater than 1 and K is an integer of 1 ≦ K ≦ N), and A K-th wiring having a different capacitance value and inductance value for connecting a fifth terminal and the fifth + K terminal,
The second switching unit includes a 6 + N terminal connected to the second terminal, a 6 + N + L terminal (M is an integer of 1 or more, and L is an integer of 1 ≦ L ≦ M), and N + L wirings having different capacitance values and inductance values for connecting the 6 + N terminals and the 6 + N + L terminals, respectively,
The third terminal and any of the fifth + K terminals are connected by bonding,
Connecting the fourth terminal and any one of the sixth + N + L terminals by bonding;
A voltage-controlled piezoelectric oscillator.

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