JP2020099102A - Oscillation module, electronic apparatus, and mobile body - Google Patents

Abstract

To provide an oscillation module capable of reducing deterioration of an oscillation signal caused by influences of magnetic field coupling generated between an oscillation circuit and a filter circuit.SOLUTION: An oscillation module includes: an oscillation circuit that has a first coil and a second coil; and a filter circuit provided at a latter stage from the oscillation circuit and that has a third coil. The first coil, the second coil and the third coil form a part of an integrated circuit. In a plan view of the integrated circuit, the third coil is arranged so as to cross a virtual straight line that is equidistant from the center of the first coil and the center of the second coil.SELECTED DRAWING: Figure 15

Description

The present invention relates to an oscillation module, an electronic device and a moving body.

Patent Document 1 discloses an oscillation differential amplifier configured by an ECL line receiver, a feedback buffer differential amplifier configured by an ECL line receiver whose output terminal is terminated by an emitter termination resistor, a switch circuit, and a voltage. A control type phase shift circuit, a SAW resonator having a predetermined resonance frequency, and an impedance circuit, and at least an oscillation differential amplifier, a feedback buffer differential amplifier, a voltage control type phase shift circuit, and a SAW resonator. Discloses an oscillation circuit in which a positive feedback oscillation loop is formed. According to this oscillator circuit, the emitter termination resistance of the feedback buffer differential amplifier is varied to increase the drive level of the SAW resonator, so that the amplitude of the signal from the SAW resonator is higher than that of noise superimposed on the signal amplitude. It becomes relatively large. In other words, since the SN ratio can be made large, it is possible to reduce the jitter caused by the noise superimposed on the signal from the SAW resonator.

JP, 2004-040509, A

This oscillating circuit outputs an oscillating signal of a frequency (fundamental frequency) near the resonance frequency of the SAW resonator, but a multiplying circuit may be provided in the subsequent stage to generate a signal of N times the frequency. The oscillation signal output from the multiplier circuit includes the fundamental frequency component in addition to the N-fold frequency component, but the fundamental frequency component can be reduced by providing a filter circuit after the multiplier circuit. In such a case, the coil included in the oscillation circuit and the coil included in the filter circuit may be magnetically coupled, and the oscillation signal may deteriorate.

The present invention has been made in view of the above problems, and according to some aspects of the present invention, deterioration of an oscillation signal due to the influence of magnetic field coupling generated between the oscillation circuit and the filter circuit is suppressed. An oscillation module that can be reduced can be provided. Further, according to some aspects of the present invention, it is possible to provide an electronic device and a moving body using the oscillation module.

The present invention has been made to solve at least a part of the problems described above, and can be realized as the following aspects or application examples.

[Application example 1]
An oscillation module according to this application example includes an oscillation circuit having a first coil and a second coil, and a filter circuit provided at a stage subsequent to the oscillation circuit and having a third coil, The first coil, the second coil, and the third coil are a part of an integrated circuit, and the third coil is a center of the first coil in a plan view of the integrated circuit. It is arranged so as to intersect a virtual straight line that is equidistant from the center of the second coil.

In the oscillation module according to this application example, the direction of the magnetic field generated by the first coil and the second coil are generated on a virtual straight line that is equidistant from the center of the first coil and the center of the second coil. The directions of the magnetic fields are reversed and weaken each other. Therefore, according to the oscillation module of this application example, it is possible to reduce the deterioration of the oscillation signal due to the influence of the magnetic field coupling between the first coil and the second coil of the oscillation circuit and the third coil of the filter circuit. You can

[Application example 2]
In the oscillation module according to the application example described above, the oscillation circuit includes a variable capacitance element, the variable capacitance element is a part of the integrated circuit, and in a plan view of the integrated circuit, the variable capacitance element is the It may be arranged between the first coil and the second coil.

According to the oscillation module of this application example, when the third coil is brought closer to the first coil and the second coil, the influence of the magnetic field generated by the first coil and the magnetic field generated by the second coil is exerted. Although it becomes easier, a variable capacitance element that is not easily affected by the magnetic field is arranged between the first coil and the second coil, so that the deterioration of the oscillation signal is reduced while suppressing an unnecessary increase in the layout area. Can be made.

[Application example 3]
In the oscillation module according to the application example, the oscillation circuit includes a differential amplifier, the differential amplifier is a part of the integrated circuit, and the differential amplifier is the planar view of the integrated circuit. It may be arranged between the variable capacitance element and the third coil.

According to the oscillation module of this application example, the variable capacitance element is arranged between the first coil and the second coil, and the differential amplifier is provided between the variable capacitance element and the third coil. Since they are arranged, the distance between the first coil and the second coil and the third coil can be increased while suppressing an unnecessary increase in the layout area. Therefore, according to the oscillation module of this application example, the magnetic field coupling between the first coil and the second coil and the third coil of the filter circuit becomes smaller, so that the oscillation signal is deteriorated due to the influence of the magnetic field coupling. Can be further reduced.

[Application example 4]
In the oscillation module according to the application example, the integrated circuit includes a first pad connected to the first coil and a second pad connected to the second coil, The distance between the first coil and the first pad is shorter than the distance between the third coil and the first pad, and the distance between the second coil and the second pad is The distance may be shorter than the distance between the third coil and the second pad.

According to the oscillation module of this application example, it is possible to shorten the length of the wiring connecting the first pad and the first coil and the length of the wiring connecting the second pad and the second coil. it can. Further, according to the oscillation module of this application example, the first pad and the second pad can be separated from the third coil, so that the frequency component of the current flowing through the first coil and the second coil can be separated. However, it is possible to reduce the risk of being coupled to the current flowing through the third coil via the first pad and the second pad. Therefore, according to the oscillation module of this application example, it is possible to further reduce the deterioration of the oscillation signal.

[Application example 5]
In the oscillation module according to the application example, the oscillation circuit has a SAW filter having a first input port, a second input port, a first output port, and a second output port, The first pad may be connected to the first output port, and the second pad may be connected to the second output port.

According to this application example, it is possible to reduce the deterioration of the oscillation signal due to the influence of the magnetic field coupling.
An AW oscillator can be realized.

[Application example 6]
In the oscillation module according to the above application example, a signal propagating from the first output port to the first input port and a signal propagating from the second output port to the second input port have opposite phases to each other. May be

According to the oscillation module of this application example, since the pair of signals propagating on the feedback path in the oscillation circuit is a differential signal, the pair of signals (differential signal) is generated by the first differential amplifier. The power supply noise that is amplified and is superimposed as common mode noise is greatly reduced. Therefore, according to the oscillation module of this application example, the frequency accuracy and S/N of the oscillation signal can be improved.

[Application example 7]
In the oscillation module according to the above application example, the oscillation circuit may operate differentially.

According to the oscillation module of this application example, since the oscillation circuit operates differentially, the power supply noise superimposed as the common mode noise on the pair of signals (oscillation signal) propagating on the feedback path in the oscillation circuit is large. Will be reduced. Therefore, according to the oscillation module of this application example, the frequency accuracy and S/N of the oscillation signal can be improved.

[Application example 8]
The oscillation module according to the application example includes an output circuit provided at a stage subsequent to the filter circuit, the oscillation circuit outputs a differential signal, and is provided on a signal path from the oscillation circuit to the output circuit. Some circuits may operate differentially.

According to the oscillation module of this application example, the power supply noise generated by the operation of the oscillation circuit is superimposed as the common mode noise on the differential signal input to each circuit provided in the subsequent stage of the oscillation circuit. Each circuit can output a differential signal whose power supply noise is greatly reduced by operating differentially. Therefore, according to the oscillation module of this application example, it is possible to output an oscillation signal with high frequency accuracy in which deterioration due to the influence of power supply noise is reduced.

[Application example 9]
An electronic device according to this application example includes any one of the oscillation modules described above.

[Application Example 10]
The moving body according to this application example includes any one of the oscillation modules described above.

According to these application examples, since the oscillation module capable of reducing the deterioration of the oscillation signal due to the influence of the magnetic field coupling generated between the oscillation circuit and the filter circuit is provided, for example, a highly reliable electronic device is provided. It is also possible to realize a mobile body.

The perspective view of the oscillation module 1 of this embodiment. Sectional drawing which cut|disconnected the oscillation module 1 by A-A' of FIG. Sectional drawing which cut|disconnected the oscillation module 1 by B-B' of FIG. The top view of SAW filter 2 and integrated circuit 3. Explanatory drawing of the effect of the oscillation module 1 of this embodiment. The block diagram which shows an example of a functional structure of the oscillation module 1 of this embodiment. The figure which shows an example of the circuit structure of the differential amplifier 20. The figure which shows an example of the input/output waveform of SAW filter 2. The figure which shows an example of the circuit structure of the differential amplifier 40. The figure which shows an example of the circuit structure of the multiplication circuit 60. The figure which shows an example of the circuit structure of the high pass filter 70. The figure which shows an example of the frequency characteristic of the high pass filter 70. The figure which shows an example of the circuit structure of the output circuit 80. FIG. 6 is a diagram showing an example of a layout arrangement of an integrated circuit 3. FIG. 6 is an enlarged view of a part of the layout arrangement of the integrated circuit 3. The figure which shows the example of arrangement|positioning of the coil 74 in a modification. The figure which shows the example of arrangement|positioning of the coil 74 in another modification. The functional block diagram which shows an example of a structure of the electronic device 300 of this embodiment. The figure which shows an example of the mobile body 400 of this embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the embodiments described below do not unduly limit the content of the invention described in the claims. Moreover, not all of the configurations described below are essential configuration requirements of the invention.

1. Oscillation module 1-1. Structure of Oscillation Module FIG. 1 is a diagram showing an example of the structure of the oscillation module 1 of the present embodiment, and is a perspective view of the oscillation module 1. 2 is a sectional view of the oscillation module 1 taken along the line AA′ in FIG. 1, and FIG. 3 is a sectional view of the oscillation module 1 taken along the line BB′ in FIG. Although FIG. 1 to FIG. 3 show the oscillation module 1 without a lid (lid), in actuality, the opening of the package 4 is covered with a lid (lid) (not shown) to form the oscillation module 1. Is configured.

As shown in FIG. 1, the oscillation module 1 of this embodiment is a SAW (Surface Acoustic Wave) oscillator, and includes a SAW filter (surface acoustic wave filter) 2, an integrated circuit (IC) 3 and a package 4. It is composed of.

The package 4 is, for example, a laminated package such as a ceramic package, and accommodates the SAW filter 2 and the integrated circuit 3 in the same space. Specifically, an opening is provided in the upper part of the package 4, and a storage chamber is formed by covering the opening with a lid (lid) (not shown), and the SAW filter 2 and the integrated unit are housed in the storage chamber. A circuit 3 is housed.

As shown in FIG. 2, the lower surface of the integrated circuit 3 is bonded and fixed to the upper surface of the first layer 4A of the package 4. Then, the electrodes (pads) 3B provided on the upper surface of the integrated circuit 3 and the electrodes 6B provided on the upper surface of the second layer 4B of the package 4 are bonded by wires 5B.

The SAW filter 2 has one end fixed to the package 4. More specifically, the lower surface of one end portion (first end portion) 2A in the longitudinal direction of the SAW filter 2 is adhesively fixed to the upper surface of the third layer 4C of the package 4 with the adhesive 7. Further, the other end (second end) 2B in the longitudinal direction of the SAW filter 2 is not fixed, and a gap is provided between the second end 2B and the inner surface of the package 4. That is, the SAW filter 2 is cantilevered and fixed to the package 4.

As shown in FIG. 1, the upper surface of the SAW filter 2 functions as a first input port IP1, a second input port IP2, a first output port OP1 and a second output port OP2 at the first end 2A. Four electrodes are provided. Then, as shown in FIGS. 1 and 3, the first input port IP1, the second input port IP2, the first output port OP1 and the second output port OP2 of the SAW filter 2 and the third layer of the package 4 are provided. Four electrodes 6A provided on the upper surface of 4C are bonded by wires 5A.

Inside the package 4, wirings (not shown) for electrically connecting the four electrodes 6A and the predetermined four electrodes 6B are provided. That is, the first input port IP1, the second input port IP2, the first output port OP1 and the second output port OP2 of the SAW filter 2 are connected via the wires 5A, 5B and the internal wiring of the package 4, It is connected to four different electrodes (pads) 3B of the integrated circuit 3, respectively.

A plurality of external electrodes (not shown) functioning as a power supply terminal, a ground terminal, or an output terminal are provided on the surface (outer surface) of the package 4, and each of the plurality of external electrodes is provided inside the package 4. Wiring (not shown) for electrically connecting each of the plurality of predetermined electrodes 6B with each other is also provided.

FIG. 4 is a plan view of the SAW filter 2 and the integrated circuit 3 when the oscillation module 1 of FIG. 1 is viewed from above from above.

As shown in FIG. 4, the SAW filter 2 includes a first IDT (Interdigital Transducer) 201, a second IDT 202, a first reflector 203, and a second IDT provided on the surface of the piezoelectric substrate 200. And a reflector 204.

The piezoelectric substrate 200 is, for example, a single crystal material such as quartz, lithium niobate (LiNbO ₃ ), lithium tantalate (LiTaO ₃ ), lithium tetraborate (Li ₂ B ₄ O ₇ , LBO), or zinc oxide (ZnO). , A piezoelectric thin film such as aluminum nitride (AlN), a piezoelectric ceramic material, or the like.

The first IDT 201 and the second IDT 202 are between the first reflector 203 and the second reflector 204, and two comb-shaped electrodes each having a plurality of electrode fingers provided at regular intervals. Are arranged so as to be interleaved with each other. Then, as shown in FIG. 2, both the electrode finger pitch of the first IDT 201 and the electrode finger pitch of the second IDT 202 are constant values d ₁ .

In addition, the SAW filter 2 includes a first input port IP1 provided on the surface of the piezoelectric substrate 200 and connected to the first IDT 201, and a second input port IP2 connected to the first IDT 201. , And has a first output port OP1 connected to the second IDT 202 and a second output port OP2 connected to the second IDT 202.

Specifically, the first wiring 205 and the second wiring 206 are provided on the surface of the piezoelectric substrate 200, and the first input port IP1 is connected to the first IDT 201 by the first wiring 205. One electrode (the upper electrode in FIG. 4) is connected, and the second input port IP2 is connected to the other electrode (the lower electrode in FIG. 4) of the first IDT 201 by the second wiring 206. There is. Further, a third wiring 207 and a fourth wiring 208 are provided on the surface of the piezoelectric substrate 200, and the first output port OP1 is connected to the one electrode of the second IDT 202 by the third wiring 207. The second output port OP2 is connected to the other electrode (the lower electrode in FIG. 4) of the second IDT 202 by the fourth wiring 208.

In the SAW filter 2 thus configured, f=v/(2d ₁ ) from the first input port IP1 and the second input port IP2 (v is the speed at which the surface acoustic wave propagates on the surface of the piezoelectric substrate 200). When an electric signal having a frequency in the vicinity is input, the first IDT 201 excites a surface acoustic wave having one wavelength equal to 2d ₁ . Then, the surface acoustic wave excited by the first IDT 201 is reflected between the first reflector 203 and the second reflector 204 to become a standing wave. The standing wave is converted into an electric signal in the second IDT 202, and is output from the first output port OP1 and the second output port OP2. That is, the SAW filter 2 functions as a narrow band bandpass filter having a center frequency of f=v/(2d ₁ ).

In the present embodiment, as shown in FIG. 4, at least a part of the SAW filter 2 overlaps with the integrated circuit 3 in a plan view. Further, the first end portion 2A of the SAW filter 2 (the hatched portion in FIG. 4) does not overlap with the integrated circuit 3 in a plan view. As described above, in the present embodiment, the SAW filter 2 is cantilevered by fixing the first end 2A of the SAW filter 2 to the package 4, and the integrated circuit 3 is arranged in the space formed below the SAW filter 2. The miniaturization of the oscillation module 1 is realized.

Further, according to the oscillation module 1 of the present embodiment, the first end 2A which is a part of the SAW filter 2 is fixed to the package 4, not the entire surface of the SAW filter 2. Therefore, the area of the fixed portion is small, There are few parts that are easily deformed by the stress applied from the package 4. Therefore, according to the oscillation module 1 of the present embodiment, it is possible to reduce the deterioration of the oscillation signal due to the stress applied to the SAW filter 2.

Further, since the back surface of the piezoelectric substrate 200 at the first end 2A of the SAW filter 2 is fixed to the package 4 by the adhesive 7, the first end 2A is easily deformed by the contraction of the adhesive 7. Therefore, in the present embodiment, as shown in FIG. 4, the first IDT 201, the second IDT 202, the first reflector 203, and the second reflector 204 are the surface of the piezoelectric substrate 200 at the first end 2A. Not provided in. As a result, the deformation of the first IDT 201 and the second IDT 202 is greatly alleviated. Therefore, according to the present embodiment, it is possible to reduce the error with respect to the target value of the electrode finger pitch d ₁ caused by the deformation of the first IDT 201 and the second IDT 202 caused by the stress due to the contraction of the adhesive 7. The oscillation module 1 with high frequency accuracy can be realized.

Further, in the present embodiment, the SAW filter 2 is cantilevered, so that stress due to contact with the package 4 is not applied to the second end 2B which is the free end. Therefore, according to the present embodiment, since the first IDT 201 and the second IDT 202 are not deformed due to the stress caused by the contact with the package 4, the oscillation module 1 with high frequency accuracy can be realized.

Further, in the present embodiment, the first input port IP1, the second input port IP2, the first output port OP1 and the second output port OP2 whose characteristics do not change due to deformation are the first end portion of the SAW filter 2. It is provided on the surface of the piezoelectric substrate 200 in 2A. As a result, the SAW filter 2 is prevented from becoming unnecessarily large and the oscillation module 1 can be downsized.

Further, in the present embodiment, as shown in FIG. 4, the SAW filter 2 has a rectangular shape having a long side 2X and a short side 2Y, and has a first input port IP1 and a second input port IP2 in a plan view. The first output port OP1 and the second output port OP2 are arranged along the long side 2X of the SAW filter 2. Therefore, according to the present embodiment, as shown in FIG. 1, the first input port IP1, the second input port IP2, the first output port OP1 and the second output port are provided outside the SAW filter 2. Since all of the four wires 5A connected to OP2 can be provided on the long side 2X side, the space on the long side of the SAW filter 2 inside the package 4 can be efficiently used and the space on the short side can be used. Since the size can be reduced, the size of the oscillation module 1 can be reduced.

Further, in the present embodiment, as shown in FIG. 4, the first input port IP1 and the second input port IP2 are arranged equidistant from the long side 2X and the first output port is seen in a plan view. OP1 and the second output port OP2 are arranged equidistant from the long side 2X. Therefore, according to the present embodiment, the length of the wiring (wire 5A and substrate wiring) connected to the first input port IP1 and the length of the wiring connected to the second input port IP2 can be easily aligned, and the first The length of the wiring connected to the output port OP1 and the length of the wiring connected to the second output port OP2 can be easily aligned, and the phase difference of 180° of the phase difference of the differential signal input to or output from the SAW filter 2 can be obtained. The deviation can be reduced.

Further, in the present embodiment, as shown in FIG. 4, the first input port IP1, the second input port IP2, the first output port OP1 and the second output port OP2 are seen from the long side 2X in plan view. They are equidistant. Therefore, the heights of the four wires 5A connected to the first input port IP1, the second input port IP2, the first output port OP1 and the second output port OP2 are easily aligned. Particularly, in the present embodiment, the first input port IP1, the second input port IP2, the first output port OP1 and the second output port OP2 are provided at positions close to the long side 2X along the long side 2X. Therefore, as shown in the sectional view on the left side of FIG. 5 (a sectional view showing a part of FIG. 3), it is possible to reduce the height H1 from the upper surface of the SAW filter 2 to the highest portion of the wire 5A. it can. On the right side of FIG. 5, it is assumed that the first input port IP1, the second input port IP2, the first output port OP1 and the second output port OP2 are provided at positions farther from the long side 2X. As shown, the height H2 from the upper surface of the SAW filter 2 to the highest part of the wire 5A is larger than H1. As described above, according to the present embodiment, the wire 5A can be lowered, so that the size of the package 4 in the height direction can be reduced, and the oscillation module 1 can be downsized.

Further, in the present embodiment, as shown in FIG. 4, in plan view, the first input port IP1, the first output port OP1, the second output port OP2, and the second input port IP1 are arranged in the direction along the long side 2X. The input ports IP2 are arranged in this order. Accordingly, when the first IDT 201 and the second IDT 202 are arranged in the direction along the long side 2X, the first wiring 205, the second wiring 206, the third wiring 207, and the fourth wiring 208 are formed. Are easily provided without crossing each other, and the length of these wirings can be shortened.

The SAW filter 2 is not limited to the configuration shown in FIG. 4, and is, for example, a transversal SAW filter that does not have a reflector and in which a surface acoustic wave propagates between an input IDT and an output IDT. Good.

1-2. Functional Configuration of Oscillation Module FIG. 6 is a block diagram showing an example of the functional configuration of the oscillation module 1 of the present embodiment. As shown in FIG. 6, the oscillation module 1 of the present embodiment includes a SAW filter 2, a phase shift circuit 10, a differential amplifier 20 (first differential amplifier), a capacitor 32, a capacitor 34, and a differential amplifier 40 (first differential amplifier). 2 differential amplifier), a condenser 52, a condenser 54, a multiplication circuit 60, a high-pass filter 70 (filter circuit), and an output circuit 80. Note that the oscillation module 1 of the present embodiment may have a configuration in which some of these elements are omitted or changed or other elements are added as appropriate.

The phase shift circuit 10, the differential amplifier 20, the capacitor 32, the capacitor 34, the differential amplifier 40, the capacitor 52, the capacitor 54, the multiplier circuit 60, the high pass filter 70, and the output circuit 80 are included in the integrated circuit 3. That is, each of these circuits is a part of the integrated circuit 3.

The first output port OP1 of the SAW filter 2 is connected to the input terminal T1 of the integrated circuit 3. Further, the second output port OP2 of the SAW filter 2 is connected to the input terminal T2 of the integrated circuit 3. Further, the first input port IP1 of the SAW filter 2 is connected to the output terminal T3 of the integrated circuit 3. Further, the second input port IP2 of the SAW filter 2 is connected to the output terminal T4 of the integrated circuit 3.

The power supply terminal T7 of the integrated circuit 3 is connected to the VDD terminal which is an external terminal (external electrode provided on the surface of the package 4) of the oscillation module 1, and the power supply terminal T7 is connected to a desired power supply via the VDD terminal. An electric potential is supplied. Further, the ground terminal T8 of the integrated circuit 3 is connected to the VSS terminal which is the external terminal of the oscillation module 1, and the ground potential (0V) is supplied to the ground terminal T8 via the VSS terminal. The phase shift circuit 10, the differential amplifier 20, the condenser 32, the condenser 34, the differential amplifier 40, the condenser 52, the condenser 54, the multiplier circuit 60, the high-pass filter 70, and the output circuit 80 have a power supply terminal T7 and a ground terminal T8. It operates using the potential difference between the two as a power supply voltage. Each power supply terminal and each ground terminal of the differential amplifier 20, the differential amplifier 40, the multiplication circuit 60, the high-pass filter 70, and the output circuit 80 are connected to the power supply terminal T7 and the ground terminal T8, respectively. Are not shown in the figure.

The phase shift circuit 10 and the differential amplifier 20 are provided on the feedback path from the first output port OP1 and the second output port OP2 of the SAW filter 2 to the first input port IP1 and the second input port IP2. ing.

The phase shift circuit 10 includes a coil 11 (first coil), a coil 12 (second coil), and a variable capacitance element 13. The inductance of the coil 11 and the inductance of the coil 12 may be the same (a difference due to manufacturing variations is allowed) or about the same.

One end of the coil 11 is connected to the input terminal T1 of the integrated circuit 3, and the other end of the coil 11 is connected to one end of the variable capacitance element 13 and the non-inverting input terminal of the differential amplifier 20. Further, one end of the coil 12 is connected to the input terminal T2 of the integrated circuit 3, and the other end of the coil 12 is connected to the other end of the variable capacitance element 13 and the inverting input terminal of the differential amplifier 20.

The variable capacitance element 13 may be, for example, a varactor (also referred to as a varicap or a variable capacitance diode) whose capacitance value changes according to an applied voltage, or may be a plurality of capacitors and at least one of a plurality of capacitors. The circuit may include a plurality of switches for selecting a unit, and the capacitance value is switched according to the selected capacitor by opening and closing the plurality of switches according to a selection signal.

The differential amplifier 20 amplifies the potential difference between a pair of signals input to the non-inverting input terminal and the inverting input terminal and outputs the pair of signals from the non-inverting output terminal and the inverting output terminal. The non-inverting output terminal of the differential amplifier 20 is connected to the output terminal T3 of the integrated circuit 3 and one end of the capacitor 32. The inverting output terminal of the differential amplifier 20 is connected to the output terminal T4 of the integrated circuit 3 and one end of the capacitor 34.

FIG. 7 is a diagram showing an example of a circuit configuration of the differential amplifier 20. In the example of FIG. 7, the differential amplifier 20 includes a resistor 21, a resistor 22, and an NMOS (Negative-channel Metal Oxide Semiconductor).
The transistor 23, the NMOS transistor 24, the constant current source 25, the NMOS transistor 26, the NMOS transistor 27, the resistor 28, and the resistor 29 are included. In FIG. 7, for example, the input terminal IP20 is a non-inverting input terminal and the input terminal IN20 is an inverting input terminal. The output terminal OP20 is a non-inverting output terminal, and the output terminal ON20 is an inverting output terminal.

The NMOS transistor 23 has a gate terminal connected to the input terminal IP20, a source terminal connected to one end of the constant current source 25, and a drain terminal connected to the power supply terminal T7 (see FIG. 6) via the resistor 21.

The NMOS transistor 24 has a gate terminal connected to the input terminal IN20, a source terminal connected to one end of the constant current source 25, and a drain terminal connected to the power supply terminal T7 (see FIG. 6) via the resistor 22.

The other end of the constant current source 25 is connected to the ground terminal T8 (see FIG. 6).

The NMOS transistor 26 has a gate terminal connected to the drain terminal of the NMOS transistor 23, a source terminal connected to the ground terminal T8 (see FIG. 6) through the resistor 28, and a drain terminal connected to the power supply terminal T7 (see FIG. 6). It is connected.

The NMOS transistor 27 has a gate terminal connected to the drain terminal of the NMOS transistor 24, a source terminal connected to the ground terminal T8 (see FIG. 6) through the resistor 29, and a drain terminal connected to the power supply terminal T7 (see FIG. 6). It is connected.

The source terminal of the NMOS transistor 26 is connected to the output terminal OP20, and the source terminal of the NMOS transistor 27 is connected to the output terminal ON20.

The differential amplifier 20 configured as described above non-inverts and amplifies a pair of signals input to the input terminal IP20 and the input terminal IN20 and outputs the signals from the output terminal OP20 and the output terminal ON20.

Returning to FIG. 6, in the present embodiment, the SAW filter 2, the phase shift circuit 10, and the differential amplifier 20 allow the first output port OP1 and the second output port OP2 of the SAW filter 2 to move to the first input port IP1 and A pair of signals propagates on the signal path reaching the second input port IP2 to form a positive feedback closed loop, and the pair of signals becomes an oscillation signal. That is, the SAW filter 2, the phase shift circuit 10, and the differential amplifier 20 constitute the oscillation circuit 100. The oscillator circuit 100 may have a configuration in which some of these elements are omitted or changed or other elements are added as appropriate.

In the upper part of FIG. 8, the waveform of the signal (frequency f ₀ ) output from the first output port OP1 of the SAW filter 2 is shown by a solid line, and the signal output from the second output port OP2 of the SAW filter 2 (frequency The waveform of f ₀ ) is shown by a broken line. In the lower part of FIG. 8, the waveform of the signal (frequency f ₀ ) input to the first input port IP1 of the SAW filter 2 is shown by a solid line, and the signal input to the second input port IP2 of the SAW filter 2 is shown. The waveform of (frequency f ₀ ) is indicated by a broken line.

As shown in FIG. 8, a signal (solid line) propagating from the first output port OP1 of the SAW filter 2 to the first input port IP1 and the second output port OP2 of the SAW filter 2 to the second input port IP2. The signals (dashed line) propagating in the signal have opposite phases. Here, the term "opposite phase to each other" means not only the case where the phase difference is exactly 180°, but also the SAW filter 2
Of the wiring of the feedback path from the first output port OP1 to the first input port IP1 of the SAW filter 2 and the wiring of the feedback path from the first output port OP1 of the SAW filter 2 to the first input port IP1 The concept also includes the case where the phase difference differs from 180° by the difference in the characteristics of the elements included in the differential amplifier 20 caused by the difference in resistance and capacitance and the manufacturing error.

As described above, the oscillation circuit 100 of the present embodiment differentially outputs the differential signals (a pair of signals having opposite phases to each other) output from the first output port OP1 and the second output port OP2 of the SAW filter 2. Amplification by the amplifier 20 and feedback to the first input port IP1 and the second input port IP2 of the SAW filter 2 constitute a closed loop feedback path to oscillate. That is, the oscillator circuit 100 operates differentially and oscillates at a frequency f ₀ according to the electrode finger pitch d ₁ of the first IDT 201 and the second IDT 202.

Then, the differential signal propagating on the feedback path from the first output port OP1 and the second output port OP2 of the SAW filter 2 to the first input port IP1 and the second input port IP2 is passed through the power supply line. The superimposed power supply noise is common mode noise, and thus is significantly reduced by the differential amplifier 20. Therefore, according to the oscillation circuit 100, it is possible to reduce the deterioration of the oscillation signal due to the influence of the power supply noise, and improve the frequency accuracy and S/N of the oscillation signal.

Further, the oscillation circuit 100 according to the present embodiment changes the capacitance value of the variable capacitance element 13 of the phase shift circuit 10 so as to respond to the inductance of the coil 11 and the inductance of the coil 12 within the pass band of the SAW filter 2. The frequency f ₀ of the oscillation signal can be changed with a variable width. The larger the inductance of the coil 11 and the larger the inductance of the coil 12, the larger the variable width of the frequency f ₀ .

Further, in the oscillation circuit 100 of the present embodiment, currents of opposite phases flow in the coil 11 and the coil 12. Therefore, since the direction of the magnetic field generated by the coil 11 and the direction of the magnetic field generated by the coil 12 are opposite and weaken each other, deterioration of the oscillation signal due to the influence of the magnetic field can be reduced.

Further, the SAW resonator has a steep frequency characteristic with respect to the reactance, whereas the SAW filter 2 has a linear (gentle) frequency characteristic with respect to the reactance. Therefore, the oscillation circuit 100 according to the present embodiment has a SAW resonator. It has an advantage that the control of the variable range of the frequency f ₀ is easy as compared with the oscillation circuit using.

Returning to FIG. 6, the oscillation module 1 includes capacitors 32, 34, a differential amplifier 40, a capacitor 52, a capacitor 54, a multiplication circuit 60, a high-pass filter 70, and an output circuit 80 in a stage subsequent to the oscillation circuit 100. There is.

One end of the capacitor 32 is connected to the non-inverting output terminal of the differential amplifier 20 (output terminal OP20 in FIG. 7), and the other end is connected to the non-inverting input terminal of the differential amplifier 40. The capacitor 34 has one end connected to the inverting output terminal of the differential amplifier 20 (output terminal ON20 in FIG. 7) and the other end connected to the inverting input terminal of the differential amplifier 40. The capacitors 32 and 34 function as DC cut capacitors and are output from the non-inverting output terminal (output terminal OP20 of FIG. 7) and the inverting output terminal (output terminal ON20 of FIG. 7) of the differential amplifier 20. The DC component of each signal is removed.

The differential amplifier 40 is provided on the signal path from the oscillation circuit 100 to the multiplication circuit 60. The differential amplifier 40 amplifies the differential signal input to the non-inverting input terminal and the inverting input terminal and outputs a differential signal from the non-inverting output terminal and the inverting output terminal.

FIG. 9 is a diagram showing an example of a circuit configuration of the differential amplifier 40. In the example of FIG. 9, the differential amplifier 40 includes a resistor 41, a resistor 42, an NMOS transistor 43, an NMOS transistor 44, and a constant current source 45. In FIG. 9, for example, the input terminal IP40 is a non-inverting input terminal and the input terminal IN40 is an inverting input terminal. The output terminal OP40 is a non-inverting output terminal, and the output terminal ON40 is an inverting output terminal.

The NMOS transistor 43 has a gate terminal connected to the input terminal IP40, a source terminal connected to one end of the constant current source 45, and a drain terminal connected to the power supply terminal T7 (see FIG. 6) via the resistor 41.

The NMOS transistor 44 has a gate terminal connected to the input terminal IN40, a source terminal connected to one end of the constant current source 45, and a drain terminal connected to the power supply terminal T7 (see FIG. 6) via the resistor 42.

The other end of the constant current source 45 is connected to the ground terminal T8 (see FIG. 6).

The drain terminal of the NMOS transistor 43 is connected to the output terminal OP40, and the drain terminal of the NMOS transistor 44 is connected to the output terminal ON40.

The differential amplifier 40 configured as described above inverts and amplifies the differential signal input to the input terminal IP40 and the input terminal IN40, and outputs the amplified differential signal from the output terminal OP40 and the output terminal ON40. ..

Returning to FIG. 6, one end of the capacitor 52 is connected to the non-inverting output terminal (output terminal OP40 of FIG. 9) of the differential amplifier 40, and the other end is connected to the non-inverting input terminal of the multiplier circuit 60. The capacitor 54 has one end connected to the inverting output terminal of the differential amplifier 40 (output terminal ON40 in FIG. 9) and the other end connected to the inverting input terminal of the multiplication circuit 60. The capacitors 52 and 54 function as capacitors for DC cut, and are output from the non-inverting output terminal (output terminal OP40 of FIG. 9) and the inverting output terminal (output terminal ON40 of FIG. 9) of the differential amplifier 40. The DC component of each signal is removed.

The multiplier circuit 60 operates differentially and outputs a differential signal obtained by multiplying the frequency f _{0 of the} differential signal input to the non-inverting input terminal and the inverting input terminal from the non-inverting output terminal and the inverting output terminal. ..

FIG. 10 is a diagram showing an example of the circuit configuration of the multiplication circuit 60. In the example of FIG. 10, the multiplication circuit 60 includes a resistor 61, a resistor 62, an NMOS transistor 63, an NMOS transistor 64, an NMOS transistor 65, an NMOS transistor 66, an NMOS transistor 67, an NMOS transistor 68, and a constant current source 69. ing. In FIG. 10, for example, the input terminal IP60 is a non-inverting input terminal and the input terminal IN60 is an inverting input terminal. The output terminal OP60 is a non-inverting output terminal, and the output terminal ON60 is an inverting output terminal.

The NMOS transistor 63 has a gate terminal connected to the input terminal IP60, a source terminal connected to the drain terminal of the NMOS transistor 65, and a drain terminal connected to the power supply terminal T7 (see FIG. 6) via the resistor 61.

The NMOS transistor 64 has a gate terminal connected to the input terminal IN60, a source terminal connected to the drain terminal of the NMOS transistor 65, and a drain terminal connected to the power supply terminal T7 (see FIG. 6) via the resistor 62.

The NMOS transistor 65 has a gate terminal connected to the input terminal IP60, a source terminal connected to one end of the constant current source 69, and a drain terminal connected to the source terminal of the NMOS transistor 63 and the source terminal of the NMOS transistor 64.

The NMOS transistor 66 has a gate terminal connected to the input terminal IN60, a source terminal connected to the drain terminal of the NMOS transistor 68, and a drain terminal connected to the power supply terminal T7 (see FIG. 6) via the resistor 61.

The NMOS transistor 67 has a gate terminal connected to the input terminal IP60, a source terminal connected to the drain terminal of the NMOS transistor 68, and a drain terminal connected to the power supply terminal T7 (see FIG. 6) via the resistor 62.

The NMOS transistor 68 has a gate terminal connected to the input terminal IN60, a source terminal connected to one end of the constant current source 69, and a drain terminal connected to the source terminal of the NMOS transistor 66 and the source terminal of the NMOS transistor 67.

The other end of the constant current source 69 is connected to the ground terminal T8 (see FIG. 6).

The drain terminal of the NMOS transistor 63 and the drain terminal of the NMOS transistor 66 are connected to the output terminal OP60, and the drain terminal of the NMOS transistor 64 and the drain terminal of the NMOS transistor 67 are connected to the output terminal ON60.

Multiplier circuit configured in this way 60 generates twice the differential signal of the frequency 2f ₀ of the frequency _{f 0} of the differential signal inputted to the input terminal IP60 and the input terminal IN60, and the output terminal OP60 Output from the output terminal ON60. In particular, the multiplication circuit 60 is a balanced modulation circuit, and in principle, the differential signal (f ₀ signal) input to the input terminal IP60 and the input terminal IN60 is output from the output terminal OP60 and the output terminal ON60. It is a configuration that is not performed. According to the multiplier circuit 60, the signal component of f ₀ output from the output terminal OP60 and the output terminal ON60 can be reduced even in consideration of manufacturing variations in each NMOS transistor and each resistor, and the purity is high. A 2f ₀ (high frequency accuracy) differential signal is obtained, and the circuit area is relatively small.

Returning to FIG. 6, the non-inverting output terminal of the multiplication circuit 60 (the output terminal OP60 of FIG. 10) is connected to the non-inverting input terminal of the high pass filter 70. Further, the inverting output terminal of the multiplication circuit 60 (output terminal ON60 in FIG. 10) is connected to the inverting input terminal of the high pass filter 70.

The high-pass filter 70 is provided on the signal path from the multiplication circuit 60 to the output circuit 80. The high-pass filter 70 operates differentially and outputs a differential signal in which low frequency components are attenuated from the differential signal input to the non-inverting input terminal and the inverting input terminal from the non-inverting output terminal and the inverting output terminal. To do.

FIG. 11 is a diagram showing an example of a circuit configuration of the high pass filter 70. In the example of FIG. 11, the high pass filter 70 includes a resistor 71, a capacitor 72, a capacitor 73, a coil 74 (third coil), a capacitor 75, a capacitor 76, and a resistor 77. In FIG. 11, for example, the input terminal IP70 is a non-inverting input terminal and the input terminal IN70 is an inverting input terminal. The output terminal OP70 is a non-inverting output terminal, and the output terminal ON70 is an inverting output terminal.

The resistor 71 has one end connected to the input terminal IP70 and one end of the capacitor 72, and the other end connected to the input terminal IN70 and one end of the capacitor 73.

One end of the capacitor 72 is connected to the input terminal IP 70 and one end of the resistor 71, and the other end is connected to one end of the coil 74 and one end of the capacitor 75.

One end of the capacitor 73 is connected to the input terminal IN70 and the other end of the resistor 71, and the other end is connected to the other end of the coil 74 and one end of the capacitor 76.

The coil 74 has one end connected to the other end of the capacitor 72 and one end of the capacitor 75, and the other end connected to the other end of the capacitor 73 and one end of the capacitor 76.

One end of the capacitor 75 is connected to the other end of the capacitor 72 and one end of the coil 74, and the other end is connected to one end of the resistor 77.

The capacitor 76 has one end connected to the other end of the capacitor 73 and the other end of the coil 74, and the other end connected to the other end of the resistor 77.

The resistor 77 has one end connected to the other end of the capacitor 75 and the other end connected to the other end of the capacitor 76.

The other end of the capacitor 75 and one end of the resistor 77 are connected to the output terminal OP70, and the other end of the capacitor 76 and the other end of the resistor 77 are connected to the output terminal ON70.

The high-pass filter 70 configured as described above generates a differential signal in which low frequency components are attenuated from the differential signal input to the input terminal IP70 and the input terminal IN70, and outputs the differential signal to the output terminal OP70 and the output terminal ON70. Output from.

FIG. 12 is a diagram showing an example of frequency characteristics of the high pass filter 70. In FIG. 12, the frequency spectrum of the output signal of the multiplying circuit 60 which is the input signal of the high pass filter 70 is also shown by the broken line. In FIG. 12, the horizontal axis represents frequency, and the vertical axis represents gain (in the case of the frequency characteristic of the high pass filter 70) or power (in the case of the frequency spectrum of the output signal of the multiplier circuit 60). As shown in FIG. 12, the resistance value of each resistor, the capacitance value of each capacitor, and the inductance value of the coil 74 are set so that the cutoff frequency f _c of the high-pass filter 70 is between f ₀ and 2f _0. There is. As described above, the multiplication circuit 60 outputs a differential signal of 2f ₀ having a small signal component of f ₀ and high purity (high frequency accuracy). However, as shown in FIG. Since the signal component of f ₀ lower than the cutoff frequency f _c is attenuated, a differential signal of 2f ₀ with higher purity (higher frequency accuracy) is obtained.

Returning to FIG. 6, the non-inverting output terminal of the high pass filter 70 (the output terminal OP70 of FIG. 11) is connected to the non-inverting input terminal of the output circuit 80. The inverting output terminal of the high-pass filter 70 (output terminal ON70 in FIG. 11) is connected to the inverting input terminal of the output circuit 80.

The output circuit 80 is provided in the subsequent stage of the multiplication circuit 60 and the high pass filter 70. The output circuit 80 operates differentially and generates a differential signal by converting a differential signal input to the non-inverting input terminal and the inverting input terminal into a signal of a desired voltage level (or current level), Output from the inverting output terminal and the inverting output terminal. The non-inverting output terminal of the output circuit 80 is connected to the output terminal T5 of the integrated circuit 3, and the inverting output terminal of the output circuit 80 is connected to the output terminal T6 of the integrated circuit 3. The output terminal T5 of the integrated circuit 3 is connected to the CP terminal which is the external terminal of the oscillation module 1, and the output terminal T6 of the integrated circuit 3 is connected to the CN terminal which is the external terminal of the oscillation module 1. Then, the differential signal (oscillation signal) converted by the output circuit 80 is output to the outside from the CP terminal and the CN terminal of the oscillation module 1 via the output terminals T5 and T6 of the integrated circuit 3.

FIG. 13 is a diagram showing an example of a circuit configuration of the output circuit 80. In the example of FIG. 13, the output circuit 80 includes a differential amplifier 81, an NPN transistor 82, and an NPN transistor 83. In FIG. 13, for example, the input terminal IP80 is a non-inverting input terminal and the input terminal IN80 is an inverting input terminal. The output terminal OP80 is a non-inverting output terminal, and the output terminal ON80 is an inverting output terminal.

In the differential amplifier 81, the non-inverting input terminal is connected to the input terminal IP80, the inverting input terminal is connected to the input terminal IN80, the non-inverting output terminal is connected to the base terminal of the NPN transistor 82, and the inverting output terminal is the NPN transistor. It is connected to the base terminal of 83 and operates with the power supply voltage VDD supplied from the power supply terminal T7 (see FIG. 6) and the ground terminal T8.

The NPN transistor 82 has a base terminal connected to the non-inverting output terminal of the differential amplifier 81, a collector terminal connected to the power supply terminal T7 (see FIG. 6), and an emitter terminal connected to the output terminal OP80.

The NPN transistor 83 has a base terminal connected to the inverting output terminal of the differential amplifier 81, a collector terminal connected to the power supply terminal T7 (see FIG. 6), and an emitter terminal connected to the output terminal ON80.

The output circuit 80 configured in this manner is a PECL (Positive Emitter Coupled Logic) circuit or an LV-PECL (Low-Voltage Positive Emitter Coupled Logic) circuit, and sets the output terminal OP80 and the output terminal ON80 to a predetermined potential V1. By pulling down, the differential signal input from the input terminal IP80 and the input terminal IN80 is converted into a differential signal in which the high level is VDD-V _CE and the low level is V1, and the output terminal OP80 and the output terminal Output from ON80. Note that V _CE is a collector-emitter voltage of the NPN transistor 82 or the NPN transistor 83.

According to the oscillation module 1 of the present embodiment described above, due to the operation of the oscillation circuit 100, each circuit (the differential amplifier 40, the multiplication circuit 60, the high-pass filter 70, the output circuit) at the stage subsequent to the oscillation circuit 100 is operated. Even if noise is superimposed on the power supplied to 80), since the respective circuits operate differentially, the power noise superimposed on the differential signal (oscillation signal) output by each circuit is common mode noise. Become. Therefore, according to the oscillation module 1 of the present embodiment, it is possible to output the oscillation signal in which the deterioration due to the influence of the power supply noise generated by the operation of the oscillation circuit 100 is reduced.

Further, according to the oscillation module 1 of the present embodiment, since the multiplication circuit 60 is provided at a stage subsequent to the oscillation circuit 100, an oscillation signal having a frequency obtained by multiplying the frequency of the oscillation signal output by the oscillation circuit 100 is output. can do.

Further, according to the oscillation module 1 of the present embodiment, since the oscillation circuit 100 operates differentially, the power supply superimposed on the differential signal (oscillation signal) propagating on the feedback path in the oscillation circuit 100 as common mode noise. Noise is greatly reduced. Therefore, according to the oscillation module 1 of the present embodiment, the frequency accuracy and S/N of the oscillation signal can be improved.

Further, according to the oscillation module 1 of the present embodiment, since the multiplication circuit 60 is a balanced modulation circuit, in principle, a signal having the same frequency as the signal input to the multiplication circuit 60 is not output from the multiplication circuit 60 ( Only the signal that the frequency of the input signal is multiplied is output). Therefore, according to the oscillation module 1 of the present embodiment, an oscillation signal having a multiplied frequency with high frequency accuracy can be obtained.

Further, in the oscillation module 1 of the present embodiment, the oscillation circuit 100 outputs a differential signal and is on a signal path from the oscillation circuit 100 to the output circuit 80 (differential amplifier 40, multiplication circuit 60 and high-pass filter). 70) operates differentially. The power supply noise generated by the operation of the oscillator circuit 100 is superimposed as a common mode noise on the differential signal input to each circuit via the power supply line. Therefore, each circuit operates by the differential power supply. A differential signal with greatly reduced noise can be output. Similarly, power supply noise (common mode noise) superimposed on the input signal of the output circuit 80 via the power supply line is greatly reduced by the output circuit 80 operating differentially. As described above, the oscillation module 1 of the present embodiment can output an oscillation signal with high frequency accuracy in which deterioration due to the influence of power supply noise generated by the operation of the oscillation circuit 100 is reduced.

Further, according to the oscillation module 1 of the present embodiment, the amplification factor of the differential amplifier 20 provided in the oscillation circuit 100 and the amplification factor of the differential amplifier 40 provided at a stage subsequent to the oscillation circuit 100 are appropriately selected. By doing so, the frequency accuracy of the oscillation signal can be optimally designed. Moreover, according to the oscillation module 1 of the present embodiment, the signal of the unnecessary frequency component included in the oscillation signal output from the multiplication circuit 60 can be reduced by the high-pass filter 70, so that the frequency accuracy of the oscillation signal is improved. be able to.

1-3. Layout of Integrated Circuit In the oscillation module 1 of this embodiment, the layout of the integrated circuit 3 is devised in order to improve the frequency accuracy of the differential signal output from the integrated circuit 3. FIG. 14 is a diagram showing an example of a layout arrangement of each circuit (excluding a part) included in the integrated circuit 3. FIG. 14 is a plan view of the integrated circuit 3 viewed from a direction orthogonal to the surface of the semiconductor substrate on which various elements (transistors, resistors, etc.) are stacked. Further, FIG. 15 is an enlarged view of the input terminal T1, the input terminal T2, the phase shift circuit 10, the differential amplifier 20, and the high-pass filter 70 in the layout layout diagram of FIG. FIG. 15 also shows the layout arrangement and a part of the wiring pattern of the coil 11, the coil 12, the variable capacitance element 13 included in the phase shift circuit 10, and the coil 74 included in the high pass filter 70.

In FIG. 15, a virtual straight line VL is a straight line that passes through the midpoint P between the center O1 of the coil 11 and the center O2 of the coil 12 and is orthogonal to the line segment L connecting the center O1 of the coil 11 and the center O2 of the coil 12, in other words. That is, the straight line is equidistant from the center O1 of the coil 11 and the center O2 of the coil 12.

In the present embodiment, as shown in FIG. 15, in the plan view of the integrated circuit 3, the coil 74 is arranged so as to intersect a virtual straight line VL that is equidistant from the center O1 of the coil 11 and the center O2 of the coil 12. Has been done. As shown in FIG. 15, the coil 74 may be arranged so that its center O3 is on the virtual straight line VL. Assuming that the wiring pattern of the coil 11 and the wiring pattern of the coil 12 are the same, the current I1 flowing through the coil 11 and the current I2 flowing through the coil 12 are in opposite directions (opposite phases). That is, when the clockwise current I1 flows through the coil 11, the counterclockwise current I2 flows through the coil 12, and when the counterclockwise current I1 flows through the coil 11, the clockwise current I2 flows through the coil 12. Therefore, on the virtual straight line VL, the direction of the magnetic field generated by the coil 11 and the direction of the magnetic field generated by the coil 12 are opposite to each other and weaken each other. If the wiring pattern of the coil 11 and the wiring pattern of the coil 12 are the same, ideally, the inductance of the coil 11 and the inductance of the coil 12 are the same, and the currents I1 and I2 are also the same. In fact, even if the manufacturing variations of the wiring and various elements are taken into consideration, the difference between the inductance of the coil 11 and the inductance of the coil 12 and the difference between the current I1 and the current I2 are small, so on the virtual straight line VL, The strength of the magnetic field generated by the coil 11 and the strength of the magnetic field generated by the coil 12 are substantially equal to each other and almost cancel each other out. Therefore, due to the magnetic field coupling between the coil 74 and the coil 11 and the coil 12, which are arranged so as to intersect the virtual straight line VL, the level of the signal f ₀ superimposed on the signal 2f ₀ output by the high-pass filter 70 is reduced. Therefore, the oscillation module 1 can output an oscillation signal with high frequency accuracy.

Further, in the present embodiment, as shown in FIG. 15, the variable capacitance element 13 is arranged between the coil 11 and the coil 12 in a plan view of the integrated circuit 3. As described above, the variable capacitance element that is close to the coils 11 and 12 and that is easily affected by the magnetic field generated by the coil 11 or the magnetic field generated by the coil 12 is not easily affected by the magnetic field between the coils 11 and 12. Arranging 13 makes it possible to suppress an unnecessary increase in the layout area. In addition, the wiring connecting the other end of the coil 11 and one end of the variable capacitance element 13 and the wiring connecting the other end of the coil 12 and the other end of the variable capacitance element 13 are both short, so that the layout area is reduced. In addition, the parasitic capacitance and parasitic resistance of these wirings can be reduced.

Further, in the present embodiment, as shown in FIG. 15, the differential amplifier 20 is arranged between the variable capacitance element 13 and the coil 74 in a plan view of the integrated circuit 3. With such a layout arrangement, the distance between the coil 11 and the coil 74 and the distance between the coil 12 and the coil 74 can be increased by the amount of the differential amplifier 20 while suppressing an unnecessary increase in the layout area. The strength of the magnetic field from the coil 11 and the strength of the magnetic field from the coil 12 received by 74 become smaller. Therefore, the level of the signal of f ₀ superimposed on the 2f ₀ signal output from the high-pass filter 70 by the magnetic field coupling between the coil 11 and the coil 12 and the coil 74 can be further reduced, and the oscillation module 1 further It is possible to output an oscillation signal with high frequency accuracy.

Further, by shortening the distance between the variable capacitance element 13 and the differential amplifier 20, as a result, the wiring that connects the other end of the coil 11 and the non-inverting input terminal of the differential amplifier 20 and the coil 12 Both the end and the wiring connecting the inverting input terminal of the differential amplifier 20 are shortened. Therefore, the layout area can be reduced, and the parasitic capacitance and parasitic resistance of the signal path from the other end of the coil 11 to the non-inverting input terminal of the differential amplifier 20 and the inversion of the differential amplifier 20 from the other end of the coil 12 can be achieved. Both the parasitic capacitance and the parasitic resistance of the signal path reaching the input terminal are reduced, and the deviation of the phase difference between the differential signals propagating through these two signal paths from 180° and the noise level superimposed on the differential signal are reduced. can do.

Further, in the present embodiment, as shown in FIG. 15, the distance (for example, the center-to-center distance) between the coil 11 and the input terminal T1 (first pad) connected to the coil 11 by wiring is equal to the coil 74. Is shorter than the distance between the input terminal T1 and the input terminal T1 (for example, the center-to-center distance). The distance between the coil 12 and the input terminal T2 (second pad) connected to the coil 12 by wiring (for example, the center-to-center distance) is the distance between the coil 74 and the input terminal T2 (for example, the center-to-center distance). Shorter than distance). With such a layout arrangement, the wiring connecting the input terminal T1 and the coil 11 and the wiring connecting the input terminal T2 and the coil 12 are shortened, so that the layout area can be reduced and the parasitic of these wirings can be reduced. Capacitance and parasitic resistance can be reduced. Therefore, the parasitic capacitance and parasitic resistance of the signal path from the input terminal T1 to one end of the coil 11 and the parasitic capacitance and parasitic resistance of the signal path from the input terminal T2 to one end of the coil 12 are both small, and these two signal paths are The deviation of the phase difference of the propagating differential signal from 180° and the noise level superimposed on the differential signal can be reduced.

Further, such a layout arrangement increases the distance between the input terminal T1 and the coil 74 and the distance between the input terminal T2 and the coil 74 (in other words, the distance between the output terminal of the high pass filter 70). Therefore, it is possible to reduce the risk that the frequency component f _{0 of the} current flowing in the coil 11 or the coil 12 is coupled to the current of the frequency 2f ₀ flowing in the coil 74 via the input terminal T1 or the input terminal T2. That is, the signal of f ₀ input to the input terminal T1 or the input terminal T2 is less likely to be superimposed on the signal of 2f ₀ output by the high-pass filter 70, and the oscillation module 1 can output an oscillation signal with high frequency accuracy. it can.

Further, in the present embodiment, as shown in FIG. 15, in the plan view of the integrated circuit 3, the differential amplifier 20 and the variable capacitance element 13 are equidistant from the center O1 of the coil 11 and the center O2 of the coil 12. It is arranged so as to intersect with the virtual straight line VL. With such a layout arrangement, the length of the wiring that connects the other end of the coil 11 and the non-inverting input terminal of the differential amplifier 20, and the wiring that connects the other end of the coil 12 and the inverting input terminal of the differential amplifier 20. The difference with the length can be reduced. Similarly, the length of the wiring that connects one end of the variable capacitance element 13 and the non-inverting input terminal of the differential amplifier 20, and the length of the wiring that connects the other end of the variable capacitance element 13 and the inverting input terminal of the differential amplifier 20. The difference from the length can be reduced. Therefore, there is a difference in parasitic capacitance or resistance between the signal path from the other end of the coil 11 to the non-inverting input terminal of the differential amplifier 20 and the signal path from the other end of the coil 12 to the inverting input terminal of the differential amplifier 20. It is possible to reduce the phase difference between the differential signals propagating through these two signal paths from 180° and the difference in the noise level superimposed on the differential signal. Therefore, the frequency accuracy and S/N of the oscillation signal output from the oscillation circuit 100 can be improved.

Further, in the present embodiment, as shown in FIG. 14, the differential amplifier 40 is provided near the differential amplifier 20, and the multiplication circuit 60 is provided at a position near both the differential amplifier 40 and the high-pass filter 70. An output circuit 80 is provided near the high pass filter 70, and an output terminal T5 and an output terminal T6 are provided near the output circuit 80. With such a layout arrangement, the wiring connecting each circuit can be shortened. Therefore, the layout area of the integrated circuit 3 can be reduced, and the phase difference of the differential signal propagating from the input terminal T1 and the input terminal T2 to the output terminal T5 and the output terminal T6 deviates from 180° or the differential. The noise level superimposed on the signal can be reduced.

As described above, according to the oscillation module 1 of the present embodiment, by adopting the layout arrangement shown in FIGS. 14 and 15, it is possible to reduce the layout area (size) of the integrated circuit 3 and reduce the frequency accuracy. It is possible to achieve both high differential signal output.

1-4. Modified Example In the above embodiment, as shown in FIG. 15, the coil 74 is arranged so that its center O3 is on the virtual straight line VL, but the coil 74 is arranged so as to intersect the virtual straight line VL. The center O3 does not have to be on the virtual straight line VL as shown in FIGS. 16 and 17.

Further, in the above embodiment, a member having an inductance on the feedback path from the first output port OP1 and the second output port OP2 of the SAW filter 2 to the first input port IP1 and the second input port IP2. By providing the coil 11 and the coil 12 as described above, the variable width of the oscillation frequency is widened. On the other hand, instead of the coil 11 and the coil 12, or together with the coil 11 and the coil 12, a member having another inductance may be provided on the return path. As the member having an inductance other than the coil, for example, there is a bonding wire or a substrate wiring, and the oscillation circuit 100 can change the oscillation frequency within a variable width according to the inductance value of the bonding wire or the substrate wiring.

Further, in the oscillation module 1 of the present embodiment, the high-pass filter 70 having the cutoff frequency f _c higher than the frequency f ₀ and including the frequency 2f ₀ in the pass band is provided in the subsequent stage of the multiplication circuit 60. The cutoff frequency on the low frequency side may be higher than the frequency f ₀ , and the bandpass filter may include the frequency 2f ₀ in the pass band.

2. Electronic Device FIG. 18 is a functional block diagram showing an example of the configuration of the electronic device of this embodiment. The electronic device 300 of the present embodiment includes an oscillation module 310, a CPU (Central Processing Unit) 320, an operation unit 330, a ROM (Read Only Memory) 340, a RAM (Random Access Memory) 350, a communication unit 360, and a display unit 370. It is composed of. Note that the electronic device according to the present embodiment may have a configuration in which some of the constituent elements (sections) in FIG. 18 are omitted or changed, or other constituent elements are added.

The oscillation module 310 includes an oscillation circuit 312. The oscillator circuit 312 includes a SAW filter (not shown) and generates an oscillation signal having a frequency based on the resonance frequency of the SAW filter.

Further, the oscillation module 310 may include a multiplication circuit 314 and an output circuit 316, which are in a stage subsequent to the oscillation circuit 312. The frequency multiplication circuit 314 generates an oscillation signal by multiplying the frequency of the oscillation signal generated by the oscillation circuit 312. Further, the output circuit 316 outputs the oscillation signal generated by the multiplication circuit 314 or the oscillation signal generated by the oscillation circuit 312 to the CPU 320. The oscillation circuit 312, the multiplication circuit 314, and the output circuit 316 may operate differentially.

The CPU 320 performs various calculation processes and control processes using the oscillation signal input from the oscillation module 310 as a clock signal according to a program stored in the ROM 340 or the like. Specifically, the CPU 320 performs various processes according to operation signals from the operation unit 330, controls the communication unit 360 to perform data communication with an external device, and causes the display unit 370 to display various information. The process of transmitting the display signal of is performed.

The operation unit 330 is an input device including operation keys, button switches, and the like, and outputs an operation signal according to an operation by the user to the CPU 320.

The ROM 340 stores programs and data for the CPU 320 to perform various calculation processes and control processes.

The RAM 350 is used as a work area of the CPU 320, and temporarily stores programs and data read from the ROM 340, data input from the operation unit 330, calculation results executed by the CPU 320 according to various programs, and the like.

The communication unit 360 performs various controls for establishing data communication between the CPU 320 and an external device.

The display unit 370 is a display device including an LCD (Liquid Crystal Display) or the like, and displays various information based on a display signal input from the CPU 320. The display unit 370 may be provided with a touch panel that functions as the operation unit 330.

By applying the oscillation circuit 100 of the above-described embodiment as the oscillation circuit 312 or applying the oscillation module 1 of the above-described embodiment as the oscillation module 310, for example, a highly reliable electronic device can be realized. ..

Various electronic devices can be considered as the electronic device 300. For example, a network device such as an optical transmission device using an optical fiber, a broadcasting device, a communication device used in an artificial satellite or a base station, or a GPS (Global Positioning) device. System) module, personal computer (for example, mobile personal computer, laptop personal computer, tablet personal computer), mobile terminal such as smartphone or mobile phone, digital camera, inkjet discharge device (for example, inkjet printer), Storage area network equipment such as routers and switches, local area network equipment, mobile terminal base station equipment, televisions, video cameras, video recorders, car navigation equipment, real-time clock equipment, pagers, electronic notebooks (including communication functions) , Electronic dictionaries, calculators, electronic game devices, game controllers, word processors, workstations, video phones, crime prevention TV monitors, electronic binoculars, POS (Point Of Sale) terminals, medical devices (eg electronic thermometers, blood pressure monitors, blood glucose meters) , Electrocardiogram measuring device, ultrasonic diagnostic device, electronic endoscope), fish finder, various measuring instruments, measuring instruments (for example, measuring instruments for vehicles, aircrafts, ships), flight simulator, head mounted display, motion trace, motion Tracking, motion controller, PDR (pedestrian position and orientation measurement) and the like can be mentioned.

An example of the electronic device 300 of the present embodiment is a transmission device that uses the above-described oscillation module 310 as a reference signal source and functions as a device for a terminal base station that performs wired or wireless communication with a terminal, for example. For example, by applying the oscillation module 1 of the above-described embodiment as the oscillation module 310, an electronic device that can be used in, for example, a communication base station and has higher frequency accuracy, higher performance, and higher reliability than before is desired. It is also possible to realize the device 300.

As another example of the electronic device 300 of the present embodiment, the communication unit 360 receives an external clock signal, and the CPU 320 (processing unit) oscillates based on the external clock signal and the output signal of the oscillation module 310. A communication device including a frequency control unit that controls the frequency of the module 310.

3. Moving Body FIG. 19 is a diagram (top view) showing an example of the moving body of the present embodiment. The moving body 400 shown in FIG. 19 is configured to include controllers 420, 430, 440 that perform various controls such as an oscillation module 410, an engine system, a brake system, a keyless entry system, a battery 450, and a backup battery 460. .. Note that the moving body of the present embodiment may have a configuration in which some of the constituent elements (respective parts) in FIG. 19 are omitted or other constituent elements are added.

The oscillation module 410 includes an oscillation circuit (not shown) including a SAW filter (not shown), and generates an oscillation signal having a frequency based on the resonance frequency of the SAW filter.

Further, the oscillation module 410 may include a multiplication circuit and an output circuit that are in a stage subsequent to the oscillation circuit. The multiplication circuit generates an oscillation signal by multiplying the frequency of the oscillation signal generated by the oscillation circuit. Further, the output circuit outputs the oscillation signal generated by the multiplication circuit or the oscillation signal generated by the oscillation circuit. The oscillation circuit, the multiplication circuit and the output circuit may operate differentially.

The oscillation signal output from the oscillation module 410 is supplied to the controllers 420, 430, 440 and used as, for example, a clock signal.

The battery 450 supplies power to the oscillation module 410 and the controllers 420, 430, 440. The backup battery 460 supplies power to the oscillation module 410 and the controllers 420, 430, 440 when the output voltage of the battery 450 drops below a threshold value.

By applying the oscillation circuit 100 of each of the above-described embodiments as the oscillation circuit included in the oscillation module 410 or by applying the oscillation module 1 of each of the above-described embodiments as the oscillation module 410, for example, a highly reliable moving body Can be realized.

Various types of moving bodies are conceivable as such moving body 400, and examples thereof include automobiles (including electric vehicles), aircraft such as jet planes and helicopters, ships, rockets, artificial satellites, and the like.

The present invention is not limited to this embodiment, and various modifications can be made within the scope of the gist of the present invention.

The embodiments and modified examples described above are merely examples, and the present invention is not limited to these. For example, each embodiment and each modification can be combined as appropriate.

The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations having the same function, method, and result, or configurations having the same purpose and effect). Further, the invention includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. Further, the invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes configurations in which known techniques are added to the configurations described in the embodiments.

1... Oscillation module, 2... SAW filter, 2A... 1st end part, 2B... 2nd end part, 2X... Long side, 2Y... Short side, 3... Integrated circuit, 3B... Electrode (pad), 4... Package, 4A... Package first layer, 4B... Package second layer, 4C... Package third layer, 4D... Package fourth layer, 5A... Wire, 5B... Wire, 6A... Electrode, 6B... Electrode, 7... Adhesive, 10... Phase shift circuit, 11... Coil, 12... Coil, 13... Variable capacitance element, 20... Differential amplifier, 21... Resistor, 22... Resistor, 23... NMOS transistor, 24... NMOS transistor, 25... Constant Current source, 26... NMOS transistor, 27... NMOS transistor, 28... Resistor, 29... Resistor, 32... Capacitor, 34... Capacitor, 40... Differential amplifier, 41... Resistor, 42... Resistor, 43... NMOS transistor, 44... NMOS transistor, 45... Constant current source, 52... Capacitor, 54... Capacitor, 60... Multiplier circuit, 61... Resistor, 62... Resistor, 63... NMOS transistor, 64... NMOS transistor, 65... NMOS transistor, 66... NMOS transistor, 67... NMOS transistor, 68... NMOS transistor, 69... Constant current source, 70... High pass filter, 71... Resistor, 72... Capacitor, 73... Capacitor, 74... Coil, 75... Capacitor, 76... Capacitor, 77... Resistor, 80 Output circuit, 81... Differential amplifier, 82... NPN transistor, 83... NPN transistor, 100... Oscillation circuit, 200... Piezoelectric substrate, 201... First IDT, 202... Second IDT, 203... First reflection Vessel, 204... second reflector, 205... first wiring, 206... second wiring, 207... third wiring, 208... fourth wiring, 300... electronic equipment, 310... oscillation module, 312... Oscillation circuit, 314... Multiplier circuit, 316... Output circuit, 320... CPU, 330... Operation unit, 340
...ROM, 350...RAM, 360...communication section, 370...display section, 400...moving body, 410...oscillation module, 420...controller, 430...controller, 440...controller, 450...battery, 460...backup battery, IP1 ...First input port, IP2...second input port, OP1...first output port, OP2...second output port, IP20...input terminal, IP40...input terminal, IP60...input terminal, IP70...input terminal , IP80...input terminal, IN20...input terminal, IN40...input terminal, IN60...input terminal, IN70...input terminal, IN80...input terminal, OP20...output terminal, OP40...output terminal, OP60...output terminal, OP70...output terminal , OP80... Output terminal, ON20... Output terminal, ON40... Output terminal, ON60... Output terminal, ON70... Output terminal, ON80... Output terminal, O1... Center of coil 11, O2... Center of coil 12, P... O1 and O2 Midpoint, L... a line segment connecting O1 and O2, VL... a virtual straight line passing through the midpoint P and orthogonal to the line segment L (straight line equidistant from O1 and O2), I1... current flowing in the coil 11, I2... current flowing through coil 12, T1... input terminal, T2... input terminal, T3... output terminal, T4... output terminal, T5... output terminal, T6... output terminal, T7... power supply terminal, T8... ground terminal

Claims (10)

An oscillator circuit having a first coil and a second coil;
A filter circuit having a third coil, the filter circuit being provided at a stage subsequent to the oscillation circuit,
The first coil, the second coil and the third coil are part of an integrated circuit,
In a plan view of the integrated circuit, the third coil is arranged so as to intersect a virtual straight line that is equidistant from the center of the first coil and the center of the second coil. .. The oscillation circuit includes a variable capacitance element,
The variable capacitance element is a part of the integrated circuit,
The oscillation module according to claim 1, wherein the variable capacitance element is arranged between the first coil and the second coil in a plan view of the integrated circuit. The oscillation circuit includes a differential amplifier,
The differential amplifier is part of the integrated circuit,
The oscillation module according to claim 2, wherein the differential amplifier is arranged between the variable capacitance element and the third coil in a plan view of the integrated circuit. The integrated circuit includes a first pad connected to the first coil and a second pad connected to the second coil,
The distance between the first coil and the first pad is shorter than the distance between the third coil and the first pad, and the distance between the second coil and the second pad. The oscillator module according to any one of claims 1 to 3, wherein is shorter than a distance between the third coil and the second pad. The oscillation circuit is
A SAW filter having a first input port, a second input port, a first output port, and a second output port,
The oscillation module according to claim 4, wherein the first pad is connected to the first output port, and the second pad is connected to the second output port. The signal propagating from the first output port to the first input port and the signal propagating from the second output port to the second input port have opposite phases to each other. Oscillation module. The oscillation module according to claim 1, wherein the oscillation circuit operates differentially. Including an output circuit provided at a stage subsequent to the filter circuit,
The oscillation circuit outputs a differential signal,
The oscillation module according to claim 1, wherein a circuit on a signal path from the oscillation circuit to the output circuit operates differentially. An electronic device comprising the oscillation module according to claim 1. A moving body comprising the oscillation module according to claim 1.

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