JP2009182805A - Temperature compensation piezoelectric oscillator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a temperature compensation piezoelectric oscillator which has little power consumption, starts in a short period of time without newly providing electrode terminals for external connection on the surface of the temperature compensation piezoelectric oscillator even if the temperature compensation piezoelectric oscillator mounted with a piezoelectric vibration element is further reduced in size. <P>SOLUTION: A first switch connects or disconnects a supply voltage terminal and a second inverter by a signal input from a function terminal, a second switch switches connection between the first switch or a cathode of a varactor diode, and a function terminal by a switching signal from a switching signal control circuit, and a third switch switches connection between a memory or the second switch and the function terminal by a switching signal from a chip select circuit. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a temperature compensated piezoelectric oscillator used in electronic equipment and the like.

A conventional temperature compensated piezoelectric oscillator mainly includes a package having a recessed space, a piezoelectric vibration element, an integrated circuit element, and a lid.
The package is formed of a substantially rectangular parallelepiped made of a ceramic material or the like, and a recessed space that is open on one main surface is formed. A mounting portion that is positioned higher than the bottom surface in the recessed space is formed in the recessed space. .
The piezoelectric vibration element is mounted on a piezoelectric vibration element mounting pad provided in the mounting portion.
The integrated circuit element is mounted on an integrated circuit element mounting pad formed on the bottom surface in the recess space of the package.
A structure is known in which the lid is hermetically sealed in the recessed space by being placed on one main surface of the package and fixed to the top of the side wall of the package.
In such a piezoelectric oscillator, a power supply voltage terminal, a ground terminal, an output terminal, and a frequency control terminal, which are external connection electrode terminals, are respectively formed at four corners of the other main surface of the package. Is known (see, for example, Patent Document 1).

FIG. 8 is a block diagram showing an integrated circuit element constituting a conventional temperature compensated piezoelectric oscillator.
As shown in FIG. 8, the integrated circuit element has a memory unit for storing temperature compensation data, a temperature sensor unit for detecting ambient temperature, a variable capacitance diode Cv, and a predetermined voltage based on the predetermined temperature compensation data. A third-order function generation circuit unit for supplying the variable capacitance diode Cv to the variable capacitance, a temperature compensation control circuit unit X including a processor unit for controlling these operations, an oscillation circuit unit Y including a load capacitor, an inverter INV1, and a feedback resistor, and an inverter An amplifier circuit unit Z composed of INV2 is provided.
The chip select terminal CS and the write / read terminal INPUT / OUTPUT are connected to the memory section of the temperature compensation control circuit section X.
The chip select terminal CS is for inputting a chip select signal to make the memory unit writable.
The write / read terminals INPUT / OUTPUT are used to write and read temperature compensation control data in the memory unit (see, for example, Patent Document 2).

Further, FIG. 9 is a circuit diagram showing a conventional piezoelectric oscillator having an inhibit terminal.
As shown in FIG. 9, the piezoelectric oscillator includes a piezoelectric vibration element Xtal, an inverter INV1 serving as an oscillation circuit, C1 and C2 serving as load capacitors, a resistor R, and an inverter INV2 serving as an amplifier circuit. A structure is known in which an inhibit terminal INH for temporarily stopping the operation of the inverter INV2 is formed (see, for example, Patent Document 3).

JP 2003-198310 A JP 2003-163542 A Model registration No. 2597382

However, when a conventional temperature compensated piezoelectric oscillator is mounted on a module used in an electronic device such as a mobile phone, the temperature compensated piezoelectric oscillator is used to reduce power consumption when the output from the temperature compensated piezoelectric oscillator is unnecessary. The intermittent operation was performed by turning ON / OFF the power supply voltage applied to the power supply voltage terminal Vdd of the piezoelectric oscillator. However, when the power supply voltage is turned ON to the temperature compensated piezoelectric oscillator, the temperature compensated piezoelectric oscillator is in the non-oscillating state. Since a predetermined rise time is required until a stable oscillation frequency is output from the start of the operation, the module does not start during the rise time.
Considering the rise time of the temperature compensated piezoelectric oscillator, the power supply voltage is applied to the temperature compensated piezoelectric oscillator prior to other electronic components mounted on the module. There is a problem that power consumption is consumed.

However, by providing a switch between the amplification inverter of the amplification circuit unit Z of the conventional temperature compensation type piezoelectric oscillator and the power supply voltage terminal Vdd and turning the switch off, the power supply voltage from the power supply voltage terminal Vdd is supplied to the amplifier circuit unit. By not applying the voltage to the inverter INV2, only the amplifier circuit unit Z is stopped, and when the temperature compensated piezoelectric oscillator oscillates, the power supply voltage is applied to the inverter INV2 of the amplifier circuit unit and the oscillation frequency is immediately output. In order to take this configuration, a new terminal called an inhibit terminal as shown in FIG. 9 is used as an external connection electrode terminal on the surface of the piezoelectric oscillator. It must be provided separately from the connection electrode terminal.
In addition, in the temperature compensated piezoelectric oscillator, a write / read terminal for writing temperature compensation data in the memory unit must be provided on the surface of the piezoelectric oscillator. Further, in the temperature compensated piezoelectric oscillator, it is necessary to provide a chip select terminal on the surface of the piezoelectric oscillator so that temperature compensation data can be written in the memory unit.
However, as the temperature-compensated piezoelectric oscillator becomes smaller, the surface area of the temperature-compensated piezoelectric oscillator also decreases, and terminals such as inhibit terminals, chip select terminals, and write / read terminals are connected to the surface of the piezoelectric oscillator as external connection electrode terminals. There was a problem that it could not be provided separately.

  Accordingly, the present invention has been made in view of the above problems, and even if the temperature-compensated piezoelectric oscillator equipped with the piezoelectric vibration element is miniaturized, the power consumption is low, and the surface of the temperature-compensated piezoelectric oscillator rises in a short time. Another object of the present invention is to provide a temperature compensated piezoelectric oscillator that does not newly provide an external connection electrode terminal.

  A temperature-compensated piezoelectric oscillator according to the present invention includes a piezoelectric vibration element, an integrated circuit element, an external connection electrode terminal, a package containing the piezoelectric vibration element and the integrated circuit element, and a hermetically sealed package. A temperature-compensated piezoelectric oscillator including a lid, and the external connection electrode terminal includes a frequency control terminal, an inhibit terminal, a function terminal that serves as a write / read terminal, a power supply voltage terminal, an output terminal, The integrated circuit element includes a first inverter that outputs an oscillation signal based on the resonance frequency of the piezoelectric vibration element, an oscillation circuit unit that includes a variable capacitance diode serving as a load capacitor, and an input An amplifying circuit unit including a second inverter for amplifying the oscillation signal to be output and outputting the output signal to the output terminal, and a first switch disposed between the second inverter of the amplifying circuit unit and the power supply voltage terminal. A second switch disposed between the first switch, the third switch, and the cathode of the variable capacitance diode, temperature compensation control data, and switching control data for switching the second switch Temperature compensation based on temperature compensation control data in the memory unit, a third switch disposed between the functional terminal, the second switch, and the connection of the memory unit Based on the temperature compensation signal control circuit unit, the switching control data in the memory unit, the switching signal control circuit unit for generating the switching signal for switching the second switch, and the power supply voltage input from the power supply voltage terminal, Switching control data for switching the second switch to the memory section, a chip select signal for enabling the temperature compensation control data to be written, and a third switch And a chip select circuit unit for outputting a switching signal for switching between the first and second switches, and the first switch connects or disconnects the power supply voltage terminal and the second inverter of the amplifier circuit unit by a signal input from the function terminal. The second switch switches the connection between the first switch or the cathode of the variable capacitance diode and the function terminal according to the switching signal from the switching signal control circuit unit, and the third switch switches the chip select circuit unit. The connection between the memory unit or the second switch and the functional terminal is switched by a switching signal from

  The chip select circuit unit compares the reference voltage generation circuit unit that generates the reference voltage, the reference voltage input from the reference voltage generation circuit unit, and the power supply voltage input from the power supply voltage terminal. The comparator is configured to output a switching signal and a chip select signal when the value is larger than the voltage or the power supply voltage and the reference voltage are the same value.

According to the temperature compensated piezoelectric oscillator of the present invention, the chip select circuit section for switching the third switch is provided, and the chip select signal is stored in the memory section by applying the power supply voltage from the power supply voltage terminal. To enable the memory unit to be written and read.
The switching signal output from the chip select circuit is input to the third switch, controls the third switch so as to connect the function terminal and the memory portion, and sets the function terminal as a write / read terminal.

In addition, when switching control data for switching the second switch is input to the memory unit from the function terminal, a switching signal for switching the second switch is generated from the switching signal control circuit unit connected to the memory unit. And the second switch is switched by this switching signal. After that, by switching the third switch from the memory unit to the second switch, it is possible to freely switch whether the function terminal becomes the inhibit terminal or the frequency control terminal.
Thus, since the output of the oscillation frequency of the piezoelectric oscillator can be stopped while the oscillation circuit unit is operating, when the power supply voltage is applied to the second inverter of the amplification circuit unit, the power supply voltage is applied to the oscillation circuit unit. Therefore, the oscillation frequency can be output immediately and the rise time can be shortened.
In addition, it is not necessary to consider the rise time of the piezoelectric oscillator, and it is not necessary to apply a power supply voltage to the piezoelectric oscillator before other electronic components mounted on the module, thus reducing the power consumption of the piezoelectric oscillator. be able to.
When the function terminal is a frequency control terminal, when a voltage is applied to the function terminal, the temperature characteristic of the piezoelectric vibration element can be corrected by changing the load capacity of the variable capacitance diode of the oscillation circuit unit.

With such a configuration, an inhibit terminal for operating a switch such as a conventional piezoelectric oscillator is separately provided as a new electrode terminal, and an external connection electrode terminal is not provided on the surface of the piezoelectric oscillator. It can be used as an inhibit terminal.
In addition, since the read / write terminal can be used as the frequency control terminal and the inhibit terminal, the write / read terminal, the frequency control terminal and the inhibit terminal are provided on the surface of the piezoelectric oscillator as new electrode terminals provided in the temperature compensated piezoelectric oscillator. Since it is not provided, it is possible to cope with further downsizing of the temperature compensated piezoelectric oscillator.
In addition, since the power supply voltage terminal and the chip select terminal can be used together, the chip select terminal is not provided on the surface of the piezoelectric oscillator as a new electrode terminal provided in the temperature compensated piezoelectric oscillator. It can cope with further miniaturization.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
For the sake of clarity, a part of the structure unnecessary for the description is not shown. Further, the illustrated dimensions are partially exaggerated.

FIG. 1 is an exploded perspective view showing a temperature compensated piezoelectric oscillator according to an embodiment of the present invention. FIG. 2 is a perspective view showing the temperature compensated piezoelectric oscillator according to the embodiment of the present invention with the other main surface of the package facing up. First, the structure of the temperature compensated piezoelectric oscillator will be described, and then the integrated circuit element will be described.
As shown in FIGS. 1 and 2, the temperature compensated piezoelectric oscillator 100 according to the embodiment of the present invention includes a piezoelectric vibration element 20, an integrated circuit element 30, and a power supply voltage terminal Vdd / that is an external connection electrode terminal 13. A package 10 for housing the piezoelectric vibration element 20 and the integrated circuit element 30, and a lid 50 for hermetically sealing the package 10, including a CS, an output terminal OUT, a ground terminal GND, and a function terminal FUNC. Consists mainly of.

For example, a quartz base plate is used as the piezoelectric vibration element 20. Excitation electrodes 21 are formed on both the front and back main surfaces of the quartz base plate, and an alternating voltage from the outside passes through the excitation electrode 21. When applied to a quartz base plate, excitation occurs in a predetermined vibration mode and frequency.
The quartz base plate is a substantially flat plate shape that is cut from an artificial crystalline lens at a predetermined cut angle and is subjected to external processing, and has a planar shape of, for example, a quadrangle.
Such a piezoelectric vibration element 20 includes an excitation electrode 21 attached to both main surfaces of the piezoelectric vibration element 20 and a piezoelectric vibration element mounting pad 15 formed on the opening side surface of the mounting portion 16 in the recessed space 11. It is mounted on the mounting portion 16 by being electrically and mechanically connected via a conductive adhesive. The mounting portion 16 is formed to be higher than the bottom surface of the recessed space 11. In addition, the piezoelectric vibration element mounting pad 15 is electrically connected to the integrated circuit element 30 via the wiring conductor and via hole conductor inside the package 10 and the integrated circuit element connection electrode pad 14 formed on the bottom surface in the recessed space. Connected.

  The conductive adhesive contains a conductive filler in a silicone resin. As the conductive powder, aluminum (Al), molybdenum (Mo), tungsten (W), platinum (Pt), palladium Those containing (Pd), silver (Ag), titanium (Ti), nickel (Ni), nickel iron (NiFe), or any combination thereof are used.

  The integrated circuit element 30 is provided with an electronic circuit including an oscillation circuit unit that generates an oscillation output from the piezoelectric vibration element 20 and a temperature compensation circuit on the circuit formation surface, and an output signal generated by the oscillation circuit is The signal is output to the outside of the piezoelectric oscillator through the output terminal OUT of the external connection electrode terminals 13, and is used as a reference signal such as a clock signal, for example. The integrated circuit element 30 is mounted on the integrated circuit element mounting pad 14 formed in the recessed space 11 of the package 10.

The package 10 is formed, for example, by laminating a plurality of insulating layers made of a ceramic material such as alumina ceramics or glass-ceramic, and a rectangular shape opening in the central region is formed on one main surface of the package 10. A recessed space 11 is formed. An annular sealing conductor pattern 12 is formed on the entire periphery of the opening side top surface of the side wall portion of the package 10 that surrounds the recessed space 11. In the recessed space 11, a mounting portion 16 provided at a position higher than the step from the bottom surface of the recessed space 11, a piezoelectric vibration element mounting pad 15 formed on the mounting portion 16, and a bottom surface of the recessed space 11 are provided. The integrated circuit element mounting pad 12 is provided. Further, the other main surface of the package 10 is provided with a power supply voltage terminal Vdd / CS, which is an external connection electrode terminal 13, a ground terminal GND, an output terminal OUT, and a function terminal FUNC. The function terminal FUNC is used as a write / read terminal INPUT / OUTPUT, an inhibit terminal INH, and a frequency control terminal Vcont.
The power supply voltage terminal Vdd is also used as a chip select terminal CS.

As shown in FIG. 1, the integrated circuit element mounting pad 14 is formed on the inner bottom surface of the recessed space 11 of the package 10.
The integrated circuit element mounting pad 14 is electrically and mechanically connected to a connection pad formed on the integrated circuit element 30, and is a wiring conductor (not shown) or via hole conductor formed inside the package 10. Etc. (not shown) are electrically connected to the power supply voltage terminal Vdd / CS, the ground terminal GND, the output terminal OUT, and the function terminal FUNC of the external connection electrode terminal 13.

  As shown in FIG. 2, the external connection electrode terminal 13 includes a power supply voltage terminal Vdd / CS, a ground terminal GND, an output terminal OUT, and a function terminal FUNC. When the oscillator 100 is mounted on an external electric circuit such as a mother board, it is electrically connected to the circuit wiring of the external electric circuit by soldering or the like.

  In addition, the sealing conductor pattern 12 formed on the top surface of the side wall portion of the package 10 has, for example, a nickel (Ni) layer and gold (Au) on the surface of a base layer made of tungsten (W), molybdenum (Mo), or the like. The layers are formed in a thickness of 10 μm to 25 μm by sequentially depositing the layers so as to surround the package 10 in an annular shape, and the sealing conductor pattern 12 has a lid 50 described later on the lid 50. It is for bonding to the top surface of the side wall portion of the package 10 through the formed sealing member 51, and a Ni layer and a surface of a base layer made of W or Mo are formed on the sealing conductor pattern 12. The structure in which the Au layer is sequentially deposited improves the wettability of the sealing member 51 with respect to the sealing conductor pattern 12, and improves the hermetic reliability and productivity of the piezoelectric oscillator 100. Improve.

  Further, as shown in FIG. 1, the lid 50 is manufactured by forming a metal such as 42 alloy into a predetermined shape by using a conventionally known metal processing method. On the upper surface of the lid 50, nickel (Ni ) Layer is formed, and a gold tin (Au—Sn) layer, which is the sealing member 51, is formed on the upper surface of the nickel (Ni) layer corresponding to the conductor pattern 12 for sealing. The thickness of the gold tin (Au—Sn) layer is 10 μm to 40 μm. For example, the component ratio is 80% gold and 20% tin. Moreover, such a sealing member 51 can relieve unevenness of the sealing conductor pattern 12 and prevent a decrease in hermeticity. Further, if the sealing member 51 is too thin, the function is not sufficiently exhibited.

FIG. 3 is a block diagram showing an example of a circuit in the integrated circuit element of the temperature compensated piezoelectric oscillator according to the embodiment of the present invention. FIG. 4 is a block diagram showing another example of a circuit in the integrated circuit element of the temperature compensated piezoelectric oscillator according to the embodiment of the present invention. FIG. 5 is a block diagram showing another example of a circuit in the integrated circuit element of the temperature compensated piezoelectric oscillator according to the embodiment of the present invention. FIG. 6 is a block diagram showing another example of a circuit in the integrated circuit element of the temperature compensated piezoelectric oscillator according to the embodiment of the present invention. FIG. 7 is a diagram showing a register map of the memory unit of the temperature compensated piezoelectric oscillator according to the embodiment of the present invention.
As shown in FIGS. 3 to 5, the integrated circuit element 30 includes an oscillation circuit unit X, an amplifier circuit unit Y, a first switch SW1, a second switch SW2, a third switch SW3, a memory It is configured to have an electronic circuit in which a part M, a temperature compensation signal control circuit part T, a switching signal control circuit part C, and a chip select circuit part CS are integrated.

  As shown in FIGS. 3 to 6, a constant voltage is applied to the oscillation circuit unit X and the amplification circuit unit Y by the power supply voltage applied to the power supply voltage terminal Vdd. 3 to 5, the power supply voltage terminal Vdd, the first inverter INV1, and the second inverter INV2 are connected to each other.

As shown in FIG. 3 to FIG. 6, the oscillation circuit unit X includes a first inverter INV1, a resistor R3, and variable capacitance diodes Cv1 and Cv2.
The first inverter INV1 of the oscillation circuit section X and the power supply voltage terminal Vdd are connected.
The resistor R3 is connected in parallel between the input and output of the first inverter INV1.
XT1, which is one end of the piezoelectric vibration element 20, is connected to the input side of the first inverter INV1, one end of the resistor R3, and the cathode of the variable capacitance diode Cv1 serving as a load capacitance. The anode of the variable capacitance diode Cv1 is connected to the ground terminal GND.
XT2, which is the other end of the piezoelectric vibration element 20, is connected to the output side of the first inverter INV1, the other end of the resistor R3, and the cathode of the variable capacitance diode Cv2 serving as a load capacitance. The anode of the variable capacitance diode Cv2 is connected to the ground terminal GND.
The function terminal FUNC is connected to the cathodes of the variable capacitance diodes Cv1 and Cv2 via the second switch SW2.

As illustrated in FIGS. 3 to 6, the amplifier circuit unit Y includes a second inverter INV2.
The input side of the second inverter INV2 of the amplifier circuit unit Y is connected to the output side of the first inverter 11 of the oscillation circuit unit X.
The output side of the second inverter INV2 of the amplifier circuit unit Y is connected to the output terminal OUT.
The second inverter INV2 of the amplifier circuit unit Y and the power supply voltage terminal Vdd are connected via the switch SW1.

As shown in FIGS. 3 to 6, the first switch SW <b> 1 is disposed between the connection between the power supply voltage terminal Vdd and the second inverter INV <b> 2 of the amplifier circuit unit Y.
The second switch SW2 is arranged between the connection of the first switch SW1, the function terminal FUNC, and the switching signal generation circuit unit C.
The third switch SW3 is disposed between the memory unit M, the function terminal FUNC, and the connection of the second switch SW2.

As shown in FIGS. 3 to 6, the memory M for storing the temperature compensation control data is composed of PROM or EEPROM.
Temperature compensation control for parameters that are the basis of a cubic function represented by the following equation 1 as a temperature compensation function, for example, a third-order component adjustment value α, a first-order component adjustment value β, and a zero-order component adjustment value γ Data is input from the write / read terminals INPUT / OUTPUT and stored in the memory unit M.
f = α (T−T ₀ ) ³ + β (T−T ₀ ) + γ (Expression 1)
Note that f indicates a frequency, α indicates a constant of a third-order component, β indicates a constant of a first-order component, γ indicates a constant of a zero-order component, and T and T ₀ indicate temperatures.
The memory unit M stores a register map.
The register map indicates how the temperature compensation signal control unit and the switching signal control circuit unit C read the control data and output a signal when the control data is input to each address data, and what kind of operation is performed. Is.
For example, as shown in FIG. 7, the address data “000” which is the temperature compensation voltage zero-order component adjustment value is associated with the temperature compensation control data “□□□”. Note that the temperature compensation control data obtained by converting the actual value corresponding to the zeroth-order component constant γ into binary, decimal, hexadecimal or the like is input as control data.
The address data “001”, which is the temperature compensation voltage primary component adjustment value, is associated with the temperature compensation control data “OO”. The temperature compensation control data obtained by converting the value corresponding to the constant β of the primary component into binary, decimal, hexadecimal or the like is input as control data.
Further, the address data “010”, which is the temperature compensation voltage tertiary component adjustment value, is associated with the temperature compensation control data “ΔΔΔ”. Note that the temperature compensation control data obtained by converting the value corresponding to the actual constant α of the third-order component into binary, decimal, hexadecimal or the like is input as control data.
Further, the address data “011” is associated with the switching control data “◇◇◇” as switching of the terminal Vcont / inhibit terminal INH used as the frequency control function. Note that switching control data converted into actual binary, decimal, hexadecimal, etc. is input as control data. The switching control data is also stored in the memory unit M together with the temperature compensation control data.
This register map is used as follows.
In order to control the function terminal FUNC to switch the frequency control terminal Vcont / inhibit terminal INH, for example, the switching control data set to switch to the inhibit terminal INH in the address data “011” is “001”. When this is input from the function terminal FUNC to the memory unit M, the second switch SW2 is switched, and the third switch SW3 and the first switch SW1 are connected. Thereafter, the third switch SW3 is switched and the function terminal FUNC and the second switch SW2 are connected, so that the function terminal FUNC and the first switch SW1 are connected, and the function terminal FUNC becomes the inhibit terminal INH.
Further, when the address data “011” is the switching control data used for switching to the frequency control terminal Vcont, and “010” is input to the memory unit M from the function terminal FUNC, the second switch SW2 is switched, The third switch SW3 and the cathodes of the variable capacitance diodes Cv1 and Cv2 are connected. Thereafter, the third switch SW3 is switched, and the function terminal FUNC and the second switch SW2 are connected, so that the function terminal FUNC and the cathodes of the variable capacitance diodes Cv1, Cv2 are connected, and the function terminal FUNC is connected to the frequency control terminal Vcont. It becomes.

The temperature compensation signal control circuit unit T includes a cubic function generation circuit, a quintic function generation circuit, and the like. For example, in the case of a cubic function generating circuit, the temperature compensation control data input to the memory unit M is read, and a voltage derived from the temperature compensation control data with a cubic function is generated for each temperature. . The external ambient temperature at this time is obtained from a temperature sensor (not shown) in the integrated circuit element.
The temperature compensation signal control circuit unit T is connected to the cathodes of the variable capacitance diodes Cv1 and Cv2, and the voltage from the temperature compensation signal control circuit unit T is applied thereto.
As described above, by applying the voltage from the temperature compensation signal control circuit T to the variable capacitance diodes Cv1 and Cv2, the frequency temperature characteristic of the piezoelectric vibration element 20 is corrected to flatten the frequency temperature characteristic.

The chip select circuit unit CS is connected to the memory unit M and the third switch SW3. A power supply voltage higher than a certain level is applied to the power supply voltage terminal Vdd, and a chip select signal CS1 is output to the memory unit M based on the power supply voltage.
Further, a power supply voltage higher than a certain level is applied to the power supply voltage terminal Vdd, and a switching signal S3 is output to the third switch SW3 based on the power supply voltage.
As a result, the memory unit M can write temperature compensation control data and switching control data, and the function terminal FUNC is connected to the memory unit M by switching the third switch SW3 by the switching signal CS1. Therefore, it can function as a write / read terminal INPUT / OUTPUT.

As illustrated in FIG. 6, the chip select circuit unit CS includes, for example, resistors R1 and R2, a comparator COMP1, and a reference voltage generation circuit unit R.
One end of the resistor R1 is connected to the power supply voltage terminal Vdd, and the other end of the resistor R1 is connected to one end of the resistor R2. The other end of the resistor R2 is connected to the ground terminal GND.
The positive input side of the comparator COMP1 is connected to the other end of the resistor R1 and one end of the resistor R2. The negative input side of the comparator COMP1 is connected to a reference voltage generation circuit unit R for applying the reference voltage Vref.
The output side of the comparator COMP1 is connected to the memory unit M and the third switch SW3.

With such a circuit configuration, the reference voltage Vref input from the reference voltage generation circuit R is compared with the power supply voltage input from the power supply voltage terminal Vdd, and the power supply voltage is greater than the reference voltage Vref or the power supply voltage is When the value is the same as the reference voltage Vref, the chip select signal CS1 is input from the comparator COMP1 to the memory unit M so that temperature compensation control data and switching control data can be written to the memory unit M.
Similarly, the switching signal S3 is output from the comparator COMP1, and the third switch SW3 is switched so that the function terminal FUNC is connected to the memory unit M.
As a result, the temperature compensation control data and the switching control data can be written or read from the function terminal FUNC that has become the write / read terminal INPUT / OUTUT in the memory unit M.

The switching signal control circuit unit C is connected to the second switch SW2. The switching control data input to the memory unit M is read, and a switching signal S2 is output to the second switch SW2 based on the switching control data.
As a result, as shown in FIGS. 3 and 4, the second switch SW2 is switched, and the third switch SW3 is switched so that the function terminal FUNC and the second switch SW2 are connected. The FUNC serves both as the inhibit terminal INH and the frequency control terminal Vcont.

Here, the write / read terminal INPUT / OUTUT writes temperature compensation control data and switching control data into the memory unit M, and reads temperature compensation control data and switching control data written in the memory unit M. It is a terminal to do.
When this function is applied, a certain voltage or more is applied from the power supply voltage terminal Vdd to the chip select circuit unit CS, and the chip select signal CS1 is input from the chip select circuit unit CS to the memory unit M. Enable to write temperature compensation control data and switching control data.
Similarly, the switching signal S3 from the chip select circuit unit CS is input to the third switch SW3, the function terminal FUNC and the memory unit M are connected, and the function terminal FUNC and the second switch SW2 are disconnected.

The inhibit terminal INH stops the supply of the power supply voltage from the power supply voltage terminal Vdd to the second inverter INV2 of the amplifier circuit unit Y, stops only the second inverter INV2 of the amplifier circuit unit Y, and the oscillation frequency of the piezoelectric oscillator A terminal that stops output.
That is, the switching signal S2 from the switching signal control circuit unit C is input to the second switch SW2, and the function becomes the inhibit terminal INH in a state where the switching is performed so as to connect the first switch SW1 and the function terminal FUNC. A constant voltage is applied to the terminal FUNC. When a constant voltage is applied, the signal S1 is input to the switch SW1 disposed between the second inverter INV2 of the amplifier circuit unit and the power supply voltage terminal Vdd, and the second inverter INV2 of the amplifier circuit unit and the power supply voltage terminal Vdd is disconnected.

The frequency control terminal Vcont is a terminal for correcting the temperature characteristics of the piezoelectric vibration element.
That is, the switching signal S2 from the switching signal control circuit unit C is input to the second switch SW2, and is switched so as to connect the cathodes of the variable capacitance diodes Cv1 and Cv2 of the oscillation circuit unit X and the function terminal FUNC. Then, a constant voltage is applied to the function terminal FUNC that has become the frequency control terminal Vcont. When a constant voltage is applied, it is connected to the cathodes of the variable capacitance diodes Cv1 and Cv2 of the oscillation circuit section X, and the load capacitance of the variable capacitance diodes Cv1 and Cv2 of the oscillation circuit section X is varied.

The switching signal S1 is switched so that the third switch SW3 is connected to the second switch SW2, and the second switch SW2 is switched so as to be connected to the first switch SW1 and the function terminal FUNC. This signal is output when a voltage is applied to the function terminal FUNC.
The switching signal S2 is transmitted from the write / read terminal INPUT / OUTPUT to the memory unit M in a state where the third switch SW3 is switched to connect the memory unit M and the write / read terminal INPUT / OUTPUT. When the switching signal control circuit unit C reads the switching control data from the memory unit M, the switching signal control circuit unit C outputs the switching data to the second switch SW2 based on the switching control data. Signal.
The switching signal S3 is a signal that is output from the chip select circuit unit CS to the third switch SW3 based on the power supply voltage when a power voltage of a certain level or higher is applied from the power supply voltage terminal Vdd.
The chip select signal CS1 is a signal that is output from the chip select circuit unit CS to the memory unit M based on the power supply voltage by applying a certain power supply voltage from the power supply voltage terminal Vdd.

As shown in FIG. 3, when the function terminal FUNC is used as the frequency control terminal Vcont, first, when switching control data is input from the write / read terminal INPUT / OUTPUT to the memory unit M, the switching signal control circuit unit C Then, the switching control data input to the memory unit M is read, and the switching signal S2 is output to the connected second switch SW2.
The third switch SW3 is switched by the output switching signal S3, and the second switch SW2 is switched by the output switching signal S2, so that the function terminals FUNC are variable capacitance diodes Cv1 and Cv2 of the oscillation circuit section X. As a result, the function terminal FUNC becomes the frequency control terminal Vcont.
As shown in FIG. 3, the load capacity is adjusted by applying a constant voltage to the function terminal FUNC that has become the frequency control terminal Vcont. Thus, by adjusting the load capacity, the oscillation characteristic of the piezoelectric vibration element 20 (Xtal) is compensated to the reference frequency.
That is, in the wide temperature range region, the voltage supplied to the variable capacitance diodes Cv1 and Cv2 is controlled, and the inherent temperature frequency characteristic of the piezoelectric vibration element 20 can be flattened over a wide temperature range.

As shown in FIG. 4, when the function terminal FUNC is used as the inhibit terminal INH, first, when switching control data is input from the write / read terminal INPUT / OUTPUT to the memory unit M, the switching signal control circuit unit C The switching control data input from the memory unit M is read, and the switching signal S2 is output to the connected second switch SW2.
The third switch SW3 is switched by the output switching signal S3, and the second switch SW2 is switched by the output switching signal S2, so that the function terminal FUNC is connected to the first switch SW1. The function terminal FUNC becomes the inhibit terminal INH.
When the function terminal FUNC becomes the inhibit terminal INH, the first switch SW1 is disconnected by the signal S1 from the function terminal FUNC. Accordingly, the power supply voltage from the power supply voltage terminal Vdd is not applied to the second inverter INV2 of the amplifier circuit unit Y, and only the second inverter INV2 of the amplifier circuit unit Y is stopped. As a result, the oscillation of the temperature compensated piezoelectric oscillator can be stopped.

  That is, by applying a voltage to the function terminal FUNC that has become the inhibit terminal INH, the piezoelectric oscillator 20 can be vibrated while the output as the piezoelectric oscillator can be stopped, so that the rise time of the piezoelectric oscillator can be shortened.

Further, as shown in FIG. 5, when the function terminal FUNC is used as the write / read terminal INPUT / OUTPUT, a voltage of a certain level or more is applied from the power supply voltage terminal Vdd to the chip select circuit unit CS, and the chip select circuit unit CS A chip select signal is output. The chip select signal CS1 is input to the memory unit M, and the memory unit M is brought into a state where control data for temperature compensation and control data for switching can be written.
Similarly, the switching signal S3 is output from the chip select circuit unit CS and input to the third switch SW3. Thereby, the third switch SW3 functions, the function terminal FUNC and the second switch SW2 are disconnected, and the function terminal FUNC is connected to the memory unit M, so that the function terminal FUNC is connected to the write / read terminal INPUT / OUTPUT. It becomes.
When the function terminal FUNC becomes the writing / reading terminal INPUT / OUTPUT, the temperature compensation control data and the switching control data can be input to the memory unit M.
When the function terminal FUNC becomes the inhibit terminal INH or the frequency control terminal Vcont, the memory unit M can be disconnected from the function terminal FUNC by the third switch SW3, and unnecessary signals are sent to the memory unit M. It is possible to prevent input.

As described above, the temperature compensated piezoelectric oscillator according to the embodiment of the present invention provides the function terminal FUNC with the frequency control terminal Vcont without providing a new terminal such as the inhibit terminal INH unlike the conventional temperature compensated piezoelectric oscillator. By also using the inhibit terminal INH, the switch SW1 disposed between the second inverter INV2 of the amplifier circuit unit Y and the power supply voltage terminal Vdd can be switched.
For example, if the function switch FUNC is switched to the inhibit terminal INH by switching the second switch SW2 and the third switch SW3, when a voltage is applied to the function terminal FUNC, the power supply voltage is applied to the second inverter INV2 of the amplifier circuit unit Y. The power supply voltage from the terminal Vdd is no longer applied, and only the second inverter INV2 of the amplifier circuit unit Y can be stopped. Accordingly, the output of the oscillation frequency of the piezoelectric oscillator can be stopped while the oscillation circuit unit X is operating. Therefore, when the power supply voltage is applied to the second inverter INV2 of the amplification circuit unit Y, the oscillation circuit unit X Since the power supply voltage is still applied, the oscillating frequency can be output immediately and the rise time can be shortened.
In addition, it is not necessary to consider the rise time of the temperature compensated piezoelectric oscillator, and it is not necessary to apply a power supply voltage to the temperature compensated piezoelectric oscillator before other electronic components mounted on the module. The power consumption applied to the piezoelectric oscillator can be reduced.
Further, by adopting such a configuration, the write / read terminal INPUT / OUTPUT, the frequency control terminal Vcont, and the inhibit terminal INH can be used together, so that the new electrode terminal provided in the temperature-compensated piezoelectric oscillator can be written / read. Since the terminal INPUT / OUTPUT, the frequency control terminal Vcont, and the inhibit terminal INH are not provided on the surface of the temperature compensated piezoelectric oscillator, it is possible to cope with further downsizing of the temperature compensated piezoelectric oscillator.
Further, since the power supply voltage terminal Vdd and the chip select terminal CS can be used together, the chip select terminal CS is not provided on the surface of the temperature compensated piezoelectric oscillator as a new electrode terminal provided in the temperature compensated piezoelectric oscillator. It is possible to cope with further downsizing of the temperature compensated piezoelectric oscillator.
Also, since the number of electrode terminals for external connection electrode terminals of the temperature compensated piezoelectric oscillator does not increase, when mounting on a motherboard that constitutes a module such as a cellular phone, wiring on the motherboard and piezoelectric oscillator are mounted. It is not necessary to change the position of the mounting pad for this purpose, and it is possible to cope with this problem by changing the software that activates the module so as to adjust the timing of applying a voltage to the mounting pad.
The chip select circuit unit CS compares the reference voltage Vref input from the reference voltage generation circuit unit R with the power supply voltage input from the power supply voltage terminal Vdd, and the power supply voltage is greater than the reference voltage Vref or the power supply voltage. When the switching signal S3 from the chip select circuit unit CS is not input to the third switch SW3 by being configured by the comparator COMP that outputs the switching signal S3 when the voltage and the reference voltage Vref have the same value, The third switch SW3 can disconnect between the function terminal FUNC and the memory unit, and can prevent an unnecessary signal from being input to the memory unit M from the function terminal FUNC.

In addition, this invention is not limited to the said embodiment, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention.
For example, in the above-described embodiment, the case where crystal is used as the piezoelectric material constituting the piezoelectric vibration element 20 has been described. However, as other piezoelectric materials, lithium niobate, lithium tantalate, or piezoelectric ceramics is used as the piezoelectric material. The piezoelectric vibration element used may be used.

  In the temperature compensated piezoelectric oscillator 100 of the present invention, the piezoelectric vibration element 20 and the integrated circuit element 30 are accommodated in the recessed space of the package 10 and hermetically sealed with a lid. A piezoelectric vibration element is mounted in the first recess space formed in the package, and an integrated circuit element is mounted in the second recess space formed on the other main surface of the package. .

1 is an exploded perspective view showing a temperature compensated piezoelectric oscillator according to an embodiment of the present invention. 1 is a perspective view showing a temperature compensated piezoelectric oscillator according to an embodiment of the present invention. It is a block diagram which shows an example of the circuit in the integrated circuit element of the temperature compensation type | mold piezoelectric oscillator which concerns on embodiment of this invention. It is a block diagram which shows another example of the circuit in the integrated circuit element of the temperature compensation type | mold piezoelectric oscillator which concerns on embodiment of this invention. It is a block diagram which shows another example of the circuit in the integrated circuit element of the temperature compensation type | mold piezoelectric oscillator which concerns on embodiment of this invention. It is a block diagram which shows an example of the circuit in the integrated circuit element of the temperature compensation type | mold piezoelectric oscillator which concerns on embodiment of this invention. It is a figure which shows the register map of the memory part of the temperature compensation type | mold piezoelectric oscillator which concerns on embodiment of this invention. It is a block diagram which shows the conventional temperature compensation type | mold piezoelectric oscillator. It is a circuit diagram which shows the conventional piezoelectric oscillator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Package 11 ... Recessed space 12 ... Conductive pattern for sealing 13 ... Electrode terminal for external connection 14 ... Piezoelectric vibration element mounting pad 15 ... Integrated circuit element mounting pad 16 ... -Mounting part 20 ... Piezoelectric vibration element 21 ... Excitation electrode 30 ... Integrated circuit element 50 ... Lid 51 ... Sealing member 100 ... Piezoelectric oscillator X ... Oscillation circuit part Y: Amplifier circuit M: Memory C: Switching signal control circuit T: Temperature compensation signal control circuit CS: Chip select circuit Cv1, Cv2: Variable capacitance diode R1 , R2, R3... Resistor INV1... First inverter INV2... Second inverter SW1... First switch SW2... Second switch SW3.・ ・Comparator Vdd ... Power supply voltage terminal CS ... Chip select terminal FUNC ... Function terminal Vcont ... Frequency control terminal INH ... Inhibit terminal OUTPUT / INPUT ... Write / read terminal OUT ... Output Terminal GND ... Ground terminal XT1, XT2 ... Piezoelectric vibration element terminal CS1 ... Chip select signal S1, S2, S3 ... Switching signal

Claims (2)

A temperature having a piezoelectric vibration element, an integrated circuit element, a package having an external connection electrode terminal, housing the piezoelectric vibration element and the integrated circuit element, and a lid for hermetically sealing the package Compensated piezoelectric oscillator,
The external connection electrode terminal is composed of a function terminal that doubles as a frequency control terminal, an inhibit terminal, and a read / write terminal, a power supply voltage terminal, an output terminal, and a ground terminal.
The integrated circuit element includes a first inverter that outputs an oscillation signal based on a resonance frequency of the piezoelectric vibration element, an oscillation circuit unit that includes a variable capacitance diode serving as a load capacitance,
An amplification circuit unit including a second inverter that amplifies the input oscillation signal and outputs the amplified oscillation signal to the output terminal;
A first switch disposed between the connection of the second inverter of the amplifier circuit unit and the power supply voltage terminal;
A second switch disposed between the connection of the first switch, the third switch, and the cathode of the variable capacitance diode;
A memory unit for storing temperature compensation control data and switching control data for switching the second switch;
A third switch disposed between the functional terminal, the second switch, and the memory unit;
A temperature compensation signal control circuit unit for performing temperature compensation based on the temperature compensation control data in the memory unit;
A switching signal control circuit unit for generating a switching signal for switching the second switch based on the switching control data in the memory unit;
Based on a power supply voltage input from the power supply voltage terminal, the switching control data for switching the second switch to the memory unit, and a chip select signal for enabling the temperature compensation control data to be written A chip select circuit unit for outputting a switching signal for switching the third switch,
The first switch connects or disconnects the power supply voltage terminal and the second inverter of the amplifier circuit unit according to a signal input from the function terminal,
The second switch switches connection between the functional terminal and the cathode of the first switch or the variable capacitance diode according to a switching signal from the switching signal control circuit unit,
The temperature-compensated piezoelectric oscillator, wherein the third switch switches connection between the memory unit or the second switch and the functional terminal according to a switching signal from the chip select circuit unit. The chip select circuit unit includes a reference voltage generation circuit unit that generates a reference voltage;
When the reference voltage input from the reference voltage generation circuit unit is compared with the power supply voltage input from the power supply voltage terminal, the power supply voltage is greater than the reference voltage or the power supply voltage and the reference voltage are the same value. 2. The temperature compensated piezoelectric oscillator according to claim 1, comprising a comparator that outputs the switching signal and the chip select signal.

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