JP2008072171A - Oscillation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a conventional oscillation device has a relatively small value of negative resistance. <P>SOLUTION: An oscillation device includes a PNP type transistor, an NPN type transistor, a crystal vibrator, a first capacitor, and a second capacitor and is characterized in that the emitter of the PNP type transistor is connected to a power supply potential; the emitter of the NPN type transistor is connected to a ground potential; one end of the first capacitor is connected to the ground potential; one end of the second capacitor is connected to the ground potential; the base of the PNP type transistor, the base of the NPN type transistor, the other end of the first capacitor, and one end of the crystal vibrator are connected to one another; and the collector of the PNP type transistor, the collector of the NPN type transistor, the other end of the second capacitor, and the other end of the crystal vibrator are connected to one another. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an oscillation device having a piezoelectric vibrator such as a crystal vibrator.

  The conventional oscillation device OSC100 illustrated in FIG. 21 generates a oscillation signal OS100, as described in Patent Document 1 below, in a resistor R100, an inverter IN100, a crystal resonator X100, and a first oscillator Capacitor C100 and a second capacitor C200. As shown in FIG. 22, the inverter IN100 includes a PMOS transistor P100 and an NMOS transistor N100.

  The oscillation device OSC100 illustrated in FIG. 22 includes a constant current source CC100 and a constant current source CC200, as illustrated in an equivalent circuit OSC100 (eq) in FIG. The constant current source CC100 supplies a constant current equal to gm100 × z100 × i100, and the constant current source CC200 supplies a constant current equal to gm100 × z100 × i100. Here, gm100 is the mutual conductance [A / V] of the PMOS transistor P100, z100 is the impedance of the first capacitor C100, i100 is the current flowing through the first capacitor C100 and the crystal resonator X100, and , Gm200 is the mutual conductance [A / V] of the NMOS transistor N100.

  When Kirchhoff's law is applied to the equivalent circuit OSC100 (eq), equations (1) and (2) are obtained.

ここで、電流ｉ２００は、第２のキャパシタＣ２００に流れる電流であり、第２のインピーダンスＺ２００は、第２のキャパシタＣ２００のインピーダンスであり、第３のインピーダンスＺ３００は、水晶振動子Ｘ１００（水晶振動子Ｘ１００の容量Ｃｘを含む。）及び抵抗器Ｒ１００のインピーダンスである。

Here, the current i200 is a current flowing through the second capacitor C200, the second impedance Z200 is the impedance of the second capacitor C200, and the third impedance Z300 is a crystal resonator X100 (crystal resonator). X100 capacitance Cx) and resistor R100 impedance.

  When the formulas (1) and (2) are arranged, the formula (3) is obtained.

第３のインピーダンスＺ３００は、（４）式により与えられる。

The third impedance Z300 is given by equation (4).

ここで、ｚｘｔは、水晶振動子Ｘ１００（容量Ｃｘを含む。）のインピーダンスを表わす。

Here, zxt represents the impedance of the crystal resonator X100 (including the capacitor Cx).

  Substituting equation (4) into equation (3) yields equation (5).

（６）式及び（７）式の条件を（５）式に代入すると、（８）式が得られる。

Substituting the conditions of equations (6) and (7) into equation (5) yields equation (8).

ここで、Ｒｂｃｉは、等価回路ＯＳＣ１００（ｅｑ）における回路側の抵抗、即ち、負性抵抗（等価回路ＯＳＣ１００（ｅｑ）を構成する素子（抵抗器、キャパシタ、水晶振動子等）のうち、水晶振動子Ｘ１００以外の素子により規定される抵抗）であり、Ｃｂｃｉは、等価回路ＯＳＣ１００（ｅｑ）における回路側のリアクタンス（等価回路ＯＳＣ１００（ｅｑ）を構成する素子（抵抗器、キャパシタ、水晶振動子等）のうち、水晶振動子Ｘ１００以外の素子により規定されるリアクタンス）である。

Here, Rbci is the resistance on the circuit side in the equivalent circuit OSC100 (eq), that is, the negative resistance (the element (resistor, capacitor, crystal resonator, etc.) constituting the equivalent circuit OSC100 (eq)). Cbci is a reactance on the circuit side in the equivalent circuit OSC100 (eq) (an element (resistor, capacitor, crystal resonator, etc.) constituting the equivalent circuit OSC100 (eq)) Among these, reactance defined by an element other than the crystal resonator X100).

JP-A-5-267935

  FIG. 24 is a simulation of the negative resistance Rbci of the above-described equivalent circuit OSC100 (eq). As shown in FIG. 24, the negative resistance Rbci of the equivalent circuit OSC100 (eq) is 0.1 kΩ (absolute value) at a frequency f = 3 MHz when gm = 0.5, and gm = 1.0. When the frequency f is 2.5 MHz, it is 1.6 kΩ (absolute value). On the other hand, in order to ensure sufficient oscillation stability, it is preferable to increase the negative resistance value (absolute value) as much as possible. However, the negative resistance of the conventional oscillation device has a relatively small value as described above, and there is a problem that sufficient oscillation stability cannot be ensured.

The first oscillation device according to the present invention is to solve the above-described problems.
A PNP transistor,
An NPN transistor;
A crystal unit,
A first capacitor;
A second capacitor;
The emitter of the PNP transistor is connected to a power supply potential;
The emitter of the NPN transistor is connected to a ground potential;
One end of the first capacitor is connected to the ground potential;
One end of the second capacitor is connected to the ground potential;
The base of the PNP transistor, the base of the NPN transistor, the other end of the first capacitor, and one end of the crystal resonator are connected to each other in an alternating manner,
The collector of the PNP transistor, the collector of the NPN transistor, the other end of the second capacitor, and the other end of the crystal resonator are connected to each other.

The first oscillation device according to the present invention described above is
A first resistor connected between the emitter of the PNP transistor and the power supply potential;
A second resistor connected between the collector and base of the PNP transistor;
A third capacitor connected between a base of the PNP transistor and a connection point between the other end of the first capacitor and one end of the crystal unit;
A third resistor connected between the emitter of the NPN transistor and the ground potential;
A fourth resistor connected between the collector and base of the NPN transistor;
And a fourth capacitor connected between a base of the NPN transistor and a connection point between the other end of the first capacitor and one end of the crystal resonator.

A second oscillation device according to the present invention includes:
An NPN transistor;
A PNP transistor,
A crystal unit,
A first capacitor;
A second capacitor;
A collector of the NPN transistor is connected to a power supply potential;
A collector of the PNP transistor is connected to a ground potential;
One end of the crystal unit is connected to the ground potential,
One end of the second capacitor is connected to the ground potential;
The base of the NPN transistor, the base of the PNP transistor, the other end of the crystal resonator, and one end of the first capacitor are connected to each other in an alternating manner,
The emitter of the NPN transistor, the emitter of the PNP transistor, the other end of the first capacitor, and the other end of the second capacitor are connected to each other.

The second oscillation device according to the present invention described above is
A first resistor connected between the collector of the NPN transistor and the power supply potential;
A second resistor connected between the collector and base of the NPN transistor;
A third capacitor connected between a base of the NPN transistor and a connection point between the other end of the crystal resonator and one end of the first capacitor;
A third resistor connected between the collector of the PNP transistor and the ground potential;
A fourth resistor connected between the collector and base of the PNP transistor;
And a fourth capacitor connected between the base of the PNP transistor, the other end of the crystal resonator, one end of the first capacitor, and a connection point of the base of the PNP transistor. .

  According to the first and second oscillation devices according to the present invention, the NPN transistor, the PNP transistor, the crystal resonator, the first capacitor, and the second capacitor are Because of the connection relationship as described above, the negative resistance can be made larger than before.

  Embodiments of an oscillation device according to the present invention will be described with reference to the drawings.

Example 1
FIG. 1 is a block diagram showing a configuration of a first embodiment of an oscillation device according to the present invention. In order to generate an oscillation signal OS (shown in FIG. 4) having an oscillation frequency f, the oscillation device OSC1 according to the first embodiment includes a PNP transistor TR1, an NPN transistor TR2, and a second transistor as shown in FIG. 1 to 9th impedances Z1 to Z9. In FIG. 1, (one) indicates “one end”, and (other) indicates “other end”.
<AC circuit>
The AC connection relationship of the oscillation device OSC1 will be described.

  The emitter of the PNP transistor TR1 is connected to the power supply potential Vcc (for example, 3V, 5V), and the emitter of the NPN transistor TR2 is connected to the ground potential GND.

  One end of the first impedance Z1 is connected to the ground potential GND, and one end of the second impedance Z2 is connected to the ground potential GND.

  Regarding the connection relationship among the PNP transistor TR1, the NPN transistor TR2, the first impedance Z1, and the third impedance Z3, the base of the PNP transistor TR1, the base of the NPN transistor TR2, the first impedance Z1, and the like. The end and one end of the third impedance Z3 are connected to each other.

  Regarding the connection relationship among the PNP transistor TR1, the NPN transistor TR2, the second impedance Z2, and the third impedance Z3, the collector of the PNP transistor TR1, the collector of the NPN transistor TR2, and the second impedance Z2 The end and the other end of the third impedance Z3 are connected to each other.

  The sixth impedance Z6 is connected between the base of the PNP transistor TR1 and a connection point IS between the other end of the first impedance Z1 and one end of the third impedance Z3. The seventh impedance Z7 is connected between the base of the NPN transistor TR2 and the connection point IS.

  Here, the PNP transistor TR1 corresponds to a “PNP transistor”, the NPN transistor TR2 corresponds to an “NPN transistor”, and the first impedance Z1 corresponds to a “first capacitor”. The second impedance Z2 corresponds to a “second capacitor”, the third impedance Z3 corresponds to a “crystal resonator”, the sixth impedance Z6 corresponds to a “third capacitor”, The seventh impedance Z7 corresponds to a “fourth capacitor”.

<DC circuit (bias circuit)>
A direct connection relationship (connection relationship from the viewpoint of bias) of the oscillation device OSC1 will be described.

  The eighth impedance Z8 is connected between the emitter of the PNP transistor TR1 and the power supply potential Vcc, and the fourth impedance Z4 is connected between the collector and base of the PNP transistor TR1.

  The ninth impedance Z9 is connected between the emitter of the NPN transistor TR2 and the ground potential GND, and the fifth impedance Z5 is connected between the collector and base of the NPN transistor TR2.

  The eighth impedance Z8 corresponds to the “first resistor”, the fourth impedance Z4 corresponds to the “second resistor”, and the ninth impedance Z9 corresponds to the “third resistor”. The fifth impedance Z5 corresponds to “fourth resistor”.

  FIG. 2 is an equivalent block diagram of the oscillation device according to the first embodiment. In the equivalent circuit OSC1 (eq) of the oscillation device OSC1, as shown in FIG. 2, the PNP transistor TR1 includes a constant current source CC1 that supplies a constant current gm × Veb (base-emitter voltage), and a base-emitter. The NPN transistor TR2 is represented by a constant current source CC2 for passing a constant current gm × Veb, a base-emitter resistance Rπ, and a base-emitter. It is represented by a capacity Cπ. Here, gm is the mutual conductance of the PNP transistor TR1 and the NPN transistor TR2.

  In the equivalent circuit OSC1 (eq), the first impedance Z1 is the capacitor C1, the second impedance Z2 is the capacitor C2, and the third impedance Z3 has the crystal resonator X (impedance value zxt). ).

  The fourth impedance Z4 is the resistor R4, the fifth impedance Z5 is the resistor R5, the sixth impedance Z6 is the capacitor C6, and the seventh impedance Z7 is the capacitor C7. The eighth impedance Z8 is a resistor R8 and a capacitor C8 connected in parallel, and the ninth impedance Z9 is a resistor R9 and a capacitor C9 connected in parallel.

  FIG. 3 shows an AC equivalent circuit of the oscillation device of the first embodiment. Note that capacitors C6, C7, C8, and C9 are not included in the components of FIG. In this case, the capacitance values are selected to such an extent that the impedances of the capacitors C6, C7, C8, and C9 can be ignored, and the capacitors C6, C7, C8, and C9 are regarded as being short-circuited in an AC manner. The AC equivalent circuit OSC1 (eq_alt) of the oscillation device OSC1 of the first embodiment is a constant current source CC3 that supplies a constant current gm × za × i1 instead of the constant current sources CC1 and CC2 illustrated in FIG. It has CC4. When Kirchhoff's law is applied to the AC equivalent circuit OSC1 (eq_alt), Equations (9) and (10) are obtained from the relationship between current and voltage, respectively.

（９）式及び（１０）式より、発振可能なインピーダンス条件を与える回路方程式である（１１）式が得られる。

From Expressions (9) and (10), Expression (11), which is a circuit equation that gives impedance conditions that allow oscillation, is obtained.

ここで、抵抗器Ｒ４＝抵抗器Ｒ５＝ＲＢとすると、相互に並列接続された、キャパシタＣ１と、２つの抵抗Ｒπと、２つの容量ＣπとからなるインピーダンスＺａ、及び、相互に並列接続された、抵抗器Ｒ４と、抵抗器Ｒ５と、水晶振動子ＸとからなるインピーダンスＺｂは、（１２）式により与えられる。

Here, when resistor R4 = resistor R5 = RB, impedance Za composed of capacitor C1, two resistors Rπ, and two capacitors Cπ connected in parallel to each other, and connected in parallel to each other The impedance Zb including the resistor R4, the resistor R5, and the crystal resonator X is given by the equation (12).

交流的等価回路ＯＳＣ１（ｅｑ＿ａｌｔ）の発振条件は、（１３）式により与えられる。

The oscillation condition of the AC equivalent circuit OSC1 (eq_alt) is given by equation (13).

ここで、Ｒｂｃｉは、交流的等価回路ＯＳＣ１（ｅｑ＿ａｌｔ）における回路側の抵抗、即ち、負性抵抗（回路を構成する素子（抵抗器、キャパシタ、水晶振動子等）のうち、水晶振動子Ｘ以外の素子により規定される抵抗）であり、Ｃｂｃｉは、交流的等価回路ＯＳＣ１（ｅｑ＿ａｌｔ）における回路側のリアクタンス（回路を構成する素子（抵抗器、キャパシタ、水晶振動子等）のうち、水晶振動子Ｘ以外の素子により規定されるリアクタンス）である。

Here, Rbci is a resistance on the circuit side in the AC equivalent circuit OSC1 (eq_alt), that is, a negative resistance (elements (resistors, capacitors, crystal oscillators, etc.) constituting the circuit other than the crystal oscillator X) Cbci is the reactance on the circuit side in the AC equivalent circuit OSC1 (eq_alt) (of the elements (resistors, capacitors, crystal resonators, etc.) constituting the circuit) Reactance defined by elements other than X).

  Negative resistance Rbci and reactance Cbci are given by equation (14).

ＰＮＰ型トランジスタＴＲ１及びＮＰＮ型トランジスタＴＲ２について、相互コンダクタンスｇｍ、ベース・エミッタ間抵抗Ｒπ、ベース・エミッタ間容量Ｃπ、電流増幅率ｈｆｅ、キャリアのベース走行時間τＦの間の関係は、（１５）式により表わされる。

For the PNP transistor TR1 and the NPN transistor TR2, the relationship among the mutual conductance gm, the base-emitter resistance Rπ, the base-emitter capacitance Cπ, the current amplification factor hfe, and the carrier base transit time τF is expressed by the following equation (15). Is represented by

図４は、本発明に係る発振装置の実施例１の具体的回路を示す。実施例１の発振装置ＯＳＣ１の具体的回路ＯＳＣ１（ｅｍｂ１）では、図４に示されるように、第１のインピーダンスＺ１は、キャパシタＣ１であり、第２のインピーダンスＺ２は、キャパシタＣ２であり、第３のインピーダンスＺ３は、水晶振動子Ｘ及び水晶振動子Ｘの内部容量Ｃ０であり、第４のインピーダンスＺ４は、抵抗器Ｒ４であり、第５のインピーダンスＺ５は、抵抗器Ｒ５であり、第６のインピーダンスＺ６は、キャパシタＣ６であり、第７のインピーダンスＺ７は、キャパシタＣ７であり、第８のインピーダンスＺ８は、並列接続された抵抗器Ｒ８及びキャパシタＣ８であり、第９のインピーダンスＺ９は、並列接続された抵抗器Ｒ９及びキャパシタＣ９である。

FIG. 4 shows a specific circuit of the first embodiment of the oscillation device according to the present invention. In the specific circuit OSC1 (emb1) of the oscillation device OSC1 of the first embodiment, as shown in FIG. 4, the first impedance Z1 is the capacitor C1, the second impedance Z2 is the capacitor C2, 3 is the crystal resonator X and the internal capacitance C0 of the crystal resonator X, the fourth impedance Z4 is the resistor R4, the fifth impedance Z5 is the resistor R5, Impedance Z6 is capacitor C6, seventh impedance Z7 is capacitor C7, eighth impedance Z8 is resistor R8 and capacitor C8 connected in parallel, and ninth impedance Z9 is parallel. A resistor R9 and a capacitor C9 are connected.

  The capacitors C1 and C2 define the oscillation frequency f in cooperation with the crystal resonator X, and the resistors R8 and R9 define the emitter currents of the PNP transistor TR1 and the NPN transistor TR2, and the resistors R4 and R5. Defines the base currents of the PNP transistor TR1 and the NPN transistor TR2, and the capacitors C6 and C7 block the DC component. Capacitor Cps is a bypass capacitor, and Ccp is a coupling capacitor.

  For the base currents of the NPN transistor TR1 and the PNP transistor TR2, a resistor connected in series between the power supply potential Vcc and the ground potential GND as shown in FIG. 5 instead of being defined by the resistors R4 and R5. It is also possible to define by means of the devices r1, r2, r3.

  FIG. 6 shows a simulation result of the AC equivalent circuit of the first embodiment of the oscillation device according to the present invention. The simulation of the AC equivalent circuit OSC1 (eq_alt) described above is performed under the conditions of transistor current amplification factor hfe = 100, carrier base transit time τF = 0.3 nsec, R4 = R5 = 20 kΩ, and C1 = C2 = 51 pF. The collector current Ic of the PNP transistor TR1 and the NPN transistor TR2 is used as a parameter.

  In the AC equivalent circuit OSC1 (eq_alt), as shown in FIG. 6, when the collector current Ic = 0.1 mA, the negative resistance Rbci = 10 kΩ (absolute value) (at this time, the frequency f = 3 MHz), the collector When current Ic = 0.2 mA, negative resistance Rbci = 13 kΩ (absolute value) (at this time, frequency f = 4.3 MHz), and when collector current Ic = 0.5 mA, negative resistance Rbci = 14 kΩ (absolute (At this time, the frequency f = 6.4 MHz), as shown in FIG. 24, the negative resistance Rbci = 1 of the conventional oscillation device OSC100 and equivalent circuit OSC100 (eq) shown in FIGS. The value can be made larger than 0.6 kΩ (absolute value).

<< Variation 1 of Embodiment 1 >>
FIG. 7 is an equivalent block diagram of Modification 1 of Embodiment 1 of the oscillation device according to the present invention. As shown in FIG. 7, the oscillation device OSC1 (eq1) of the first modification of the first embodiment basically has the same configuration as the equivalent circuit OSC1 (eq) of the first embodiment. The difference from the equivalent circuit OSC1 (eq) of the first embodiment is that the second impedance Z2 (shown in FIG. 1) is constituted by a capacitor C2a and an inductor L2a connected in series instead of the second capacitor C2. It is being done.

  Therefore, the negative resistance Rbci and reactance Cbci of the equivalent circuit OSC1 (eq1) of the first modification give the negative resistance Rbci and reactance Cbci of the equivalent circuit OSC1 (eq) of the first embodiment. Is obtained by substituting C2 shown in equation (16).

図８は、実施例１の変形例１の等価回路のシミュレーション結果を示したものである。当該シミュレーションは、トランジスタの電流増幅率ｈｆｅ＝１００、キャリアのベース走行時間τＦ＝０．３ｎｓｅｃ、Ｒ４＝Ｒ５＝２０ｋΩ、Ｃ１＝２０ｐＦ、Ｃ２ａ＝１０ｐＦ、Ｌ２ａ＝１０μＨを条件としている。

FIG. 8 shows a simulation result of the equivalent circuit of the first modification of the first embodiment. The simulation is based on the following conditions: transistor current amplification factor hfe = 100, carrier base transit time τF = 0.3 nsec, R4 = R5 = 20 kΩ, C1 = 20 pF, C2a = 10 pF, L2a = 10 μH.

  In the equivalent circuit OSC1 (eq1), as shown in FIG. 8, the negative resistance Rbci is 10 kΩ (absolute value) at the oscillation frequency f = 9 MHz, and 1.6 kΩ of the negative resistance Rbci of the conventional oscillation device OSC100. As a comparison, a larger value can be obtained. Further, as is clear from comparison with FIG. 6 showing the simulation result of the negative resistance Rbci of the equivalent circuit OSC1 (eq) of the first embodiment, the equivalent circuit OSC1 (eq) of the first embodiment (where the collector current Ic = 0.5 mA) is equivalent to the equivalent circuit OSC1 of the first modification of the first embodiment, in contrast to the case where the value of the negative resistance Rbci is 0 or less, that is, oscillation is possible at a frequency from 6 MHz to 100 MHz. (Eq1) can oscillate at frequencies from 8 MHz to 16 MHz, and the equivalent circuit OSC1 (eq1) performs stable oscillation in a narrow band as compared with the equivalent circuit OSC1 (eq) of the first embodiment. It becomes possible.

<< Modification 2 of Embodiment 1 >>
FIG. 9 is an equivalent block diagram of Modification 2 of Embodiment 1 of the oscillation device according to the present invention. As shown in FIG. 9, the oscillation device OSC1 (eq2) of the second modification of the first embodiment has basically the same configuration as the equivalent circuit OSC1 (eq) of the oscillation device OSC1 of the first embodiment. The difference from the equivalent circuit OSC1 (eq) of the first embodiment is that a second impedance Z2 (shown in FIG. 1) is constituted by a capacitor C2a and an inductor L2a connected in parallel instead of the second capacitor C2. It is being done.

  Therefore, the negative resistance Rbci and reactance Cbci of the equivalent circuit OSC1 (eq2) of the second modification give the negative resistance Rbci and reactance Cbci of the equivalent circuit OSC1 (eq) of the first embodiment. Is obtained by substituting C2 shown in Equation (17).

図１０は、実施例１の変形例２の等価回路のシミュレーション結果を示したものである。当該シミュレーションは、実施例１の変形例１の発振装置ＯＳＣ１（ｅｑ１）のシミュレーションと同様に、トランジスタの電流増幅率ｈｆｅ＝１００、キャリアのベース走行時間τＦ＝０．３ｎｓｅｃ、Ｒ４＝Ｒ５＝２０ｋΩ、Ｃ１＝２０ｐＦ、Ｃ２ａ＝１０ｐＦ、Ｌ２ａ＝１０μＨを条件としている。

FIG. 10 shows a simulation result of the equivalent circuit of the second modification of the first embodiment. The simulation is similar to the simulation of the oscillation device OSC1 (eq1) of the first modification of the first embodiment, the transistor current amplification factor hfe = 100, the carrier base travel time τF = 0.3 nsec, R4 = R5 = 20 kΩ, The conditions are C1 = 20 pF, C2a = 10 pF, and L2a = 10 μH.

  In the equivalent circuit OSC1 (eq2) of Modification 2, as shown in FIG. 10, the negative resistance Rbci is 10 kΩ (absolute value) at the frequency f = 9 MHz, and the negative resistance Rbci of the conventional oscillation device OSC100 is Compared to 1.6 kΩ, a larger value can be obtained. Further, as is clear from comparison with FIG. 8 that shows the simulation result of the negative resistance Rbci of the equivalent circuit OSC1 (eq1) of the first modification, the equivalent circuit OSC1 (eq1) of the first modification has a frequency range from 8 MHz to 16 MHz. In contrast to being able to oscillate at a frequency, the equivalent circuit OSC1 (eq2) of the modification 2 can oscillate at a frequency from 6.5 MHz to 13 MHz, and the equivalent circuit OSC1 (eq2) of the modification 2 is As compared with the equivalent circuit OSC1 (eq1) of the modified example 1, stable oscillation can be performed in a narrower band.

Example 2
FIG. 11 is a block diagram illustrating a configuration of the oscillation device according to the second embodiment. As shown in FIG. 11, the oscillation device OSC2 of the second embodiment differs from the oscillation device OSC1 of the first embodiment in order to generate an oscillation signal OS having an oscillation frequency f. Instead of the PNP transistor TR1, the oscillation device OSC2 It has a transistor TR1, has a PNP transistor TR2 instead of the NPN transistor TR2, and includes first to ninth impedances Z1 to Z9 as in the oscillation device OSC1 of the first embodiment. In FIG. 11, (one) indicates “one end” and (other) indicates “the other end”.

<AC circuit>
The AC connection relationship of the oscillation device OSC2 will be described.

  NPN transistor TR1 has its collector connected to power supply potential Vcc, and PNP transistor TR2 has its collector connected to ground potential GND.

  One end of the third impedance Z3 is connected to the ground potential GND, and one end of the second impedance Z2 is connected to the ground potential GND.

  Regarding the connection relationship between the NPN transistor TR1, the PNP transistor TR2, the third impedance Z3, and the first impedance Z1, the base of the NPN transistor TR1, the base of the PNP transistor TR2, and the third impedance Z3 The end and one end of the first impedance Z1 are connected to each other.

  Regarding the connection relationship among the NPN transistor TR1, the PNP transistor TR2, the first impedance Z1, and the second impedance Z2, the emitter of the NPN transistor TR1, the emitter of the PNP transistor TR2, the first impedance Z1, and the like. The end and the other end of the second impedance Z2 are connected to each other.

  The sixth impedance Z6 is connected between the base of the NPN transistor TR1 and a connection point IS between the other end of the third impedance Z3 and one end of the first impedance Z1. The seventh impedance Z7 is connected between the base of the PNP transistor TR2 and the connection point IS.

  Here, the NPN transistor TR1 corresponds to an “NPN transistor”, the PNP transistor TR2 corresponds to a “PNP transistor”, and the first impedance Z1 corresponds to a “first capacitor”. The second impedance Z2 corresponds to a “second capacitor”, the third impedance Z3 corresponds to a “crystal resonator”, the sixth impedance Z6 corresponds to a “third capacitor”, The seventh impedance Z7 corresponds to a “fourth capacitor”.

<DC circuit (bias circuit)>
A direct connection relationship of the oscillation device OSC2 will be described.

  The eighth impedance Z8 is connected between the collector of the NPN transistor TR1 and the power supply potential Vcc, and the fourth impedance Z4 is connected between the collector and base of the NPN transistor TR1.

  The ninth impedance Z9 is connected between the collector of the PNP transistor TR2 and the ground potential GND, and the fifth impedance Z5 is connected between the collector and base of the PNP transistor TR2.

  The eighth impedance Z8 corresponds to a “first resistor”, the fourth impedance Z4 corresponds to a “second resistor”, and the ninth impedance Z9 corresponds to a “third resistor”. The fifth impedance Z5 corresponds to a “fourth resistor”.

  FIG. 12 is an equivalent block diagram of the oscillation device according to the second embodiment. In the equivalent circuit OSC2 (eq) of the oscillation device OSC2, as shown in FIG. 12, the NPN transistor TR1 includes a constant current source CC1 for passing a constant current gm × Veb (base-emitter voltage) and a base-emitter. The PNP transistor TR2 is represented by a resistance Rπ and a base-emitter capacitance Cπ. The PNP transistor TR2 includes a constant current source CC2 for passing a constant current gm × Veb, a base-emitter resistance Rπ, and a base-emitter capacitance. It is represented by Cπ. Here, gm is the mutual conductance of the NPN transistor TR1 and the PNP transistor TR2.

  In the equivalent circuit OSC2 (eq), the first impedance Z1 is the capacitor C1, the second impedance Z2 is the capacitor C2, and the third impedance Z3 has the crystal resonator X (impedance value zxt). ).

  As in the equivalent circuit OSC1 (eq) of the first embodiment, the fourth impedance Z4 is the resistor R4, the fifth impedance Z5 is the resistor R5, and the sixth impedance Z6 is a capacitor. C6, the seventh impedance Z7 is the capacitor C7, the eighth impedance Z8 is the resistor R8 and the capacitor C8 connected in parallel, and the ninth impedance Z9 is the resistor R9 connected in parallel. And capacitor C9.

  FIG. 13 illustrates an AC equivalent circuit of the oscillation device according to the second embodiment. An AC equivalent circuit OSC2 (eq_alt) of the oscillation device OSC2 of the second embodiment is replaced with a constant current source CC3 that supplies a constant current gm × za × i1 instead of the constant current sources CC1 and CC2 illustrated in FIG. It has CC4. When Kirchhoff's law is applied to the AC equivalent circuit OSC2 (eq_alt), Equations (18) and (19) are obtained from the relationship between current and voltage, respectively.

（１８）式及び（１９）式より、発振可能なインピーダンス条件を与える回路方程式である（２０）式が得られる。

From Equations (18) and (19), Equation (20), which is a circuit equation that gives an oscillating impedance condition, is obtained.

ここで、抵抗器Ｒ４＝抵抗器Ｒ５＝ＲＢとすると、相互に並列接続された、キャパシタＣ１と、２つの抵抗Ｒπと、２つの容量ＣπとからなるインピーダンスＺａ、及び、相互に並列接続された、抵抗器Ｒ４と、水晶振動子Ｘと、抵抗器Ｒ５とからなるインピーダンスＺｂは、（２１）式により与えられる。

Here, when resistor R4 = resistor R5 = RB, impedance Za composed of capacitor C1, two resistors Rπ, and two capacitors Cπ connected in parallel to each other, and connected in parallel to each other The impedance Zb formed by the resistor R4, the crystal unit X, and the resistor R5 is given by the equation (21).

交流的等価回路ＯＳＣ２（ｅｑ＿ａｌｔ）の発振条件は、（２２）式により与えられる。

The oscillation condition of the AC equivalent circuit OSC2 (eq_alt) is given by equation (22).

負性抵抗Ｒｂｃｉ、リアクタンスＣｂｃｉは、（２３）式により与えられる。

Negative resistance Rbci and reactance Cbci are given by equation (23).

ＮＰＮ型トランジスタＴＲ１及びＰＮＰ型トランジスタＴＲ２について、相互コンダクタンスｇｍ、ベース・エミッタ間抵抗Ｒπ、ベース・エミッタ間容量Ｃπ、電流増幅率ｈｆｅ、キャリアのベース走行時間τＦの間の関係は、（２４）式により表わされる。

For the NPN transistor TR1 and the PNP transistor TR2, the relationship among the mutual conductance gm, the base-emitter resistance Rπ, the base-emitter capacitance Cπ, the current amplification factor hfe, and the carrier base transit time τF is expressed by the following equation (24). Is represented by

図１４は、実施例２の発振装置の具体的回路を示す。実施例２の発振装置ＯＳＣ２の具体的回路ＯＳＣ２（ｅｍｂ１）では、図１４に示されるように、第１のインピーダンスＺ１は、キャパシタＣ１であり、第２のインピーダンスＺ２は、キャパシタＣ２であり、第３のインピーダンスＺ３は、水晶振動子Ｘ及び水晶振動子Ｘの内部容量Ｃ０であり、第４のインピーダンスＺ４は、抵抗器Ｒ４であり、第５のインピーダンスＺ５は、抵抗器Ｒ５であり、第６のインピーダンスＺ６は、キャパシタＣ６であり、第７のインピーダンスＺ７は、キャパシタＣ７であり、第８のインピーダンスＺ８は、並列接続された抵抗器Ｒ８及びキャパシタＣ８であり、第９のインピーダンスＺ９は、並列接続された抵抗器Ｒ９及びキャパシタＣ９である。

FIG. 14 illustrates a specific circuit of the oscillation device according to the second embodiment. In the specific circuit OSC2 (emb1) of the oscillation device OSC2 of the second embodiment, as shown in FIG. 14, the first impedance Z1 is the capacitor C1, the second impedance Z2 is the capacitor C2, 3 is the crystal resonator X and the internal capacitance C0 of the crystal resonator X, the fourth impedance Z4 is the resistor R4, the fifth impedance Z5 is the resistor R5, Impedance Z6 is capacitor C6, seventh impedance Z7 is capacitor C7, eighth impedance Z8 is resistor R8 and capacitor C8 connected in parallel, and ninth impedance Z9 is parallel. A resistor R9 and a capacitor C9 are connected.

  The capacitors C1 and C2 cooperate with the crystal resonator X to define the oscillation frequency f, and the resistors R8 and R9 define the emitter currents of the NPN transistor TR1 and the PNP transistor TR2, and the resistors R4 and R5. Defines the base currents of the NPN transistor TR1 and the PNP transistor TR2, and the capacitors C6 and C7 block the DC component. Capacitor Cps is a bypass capacitor, and Ccp is a coupling capacitor.

  The base currents of the PNP transistor TR1 and the NPN transistor TR2 are not limited by the resistors R4 and R5, but are connected in series between the power supply potential Vcc and the ground potential GND as shown in FIG. It is also possible to define by means of the devices r1, r2, r3.

  FIG. 16 shows a simulation result of the AC equivalent circuit of the oscillation device according to the second embodiment of the present invention. The simulation of the AC equivalent circuit OSC2 (eq_alt) described above is similar to the AC equivalent circuit OSC1 (eq_alt) of the first embodiment. The transistor current amplification factor hfe = 100 and the carrier base travel time τF = 0.3 nsec. , R4 = R5 = 20 kΩ, and C1 = C2 = 51 pF, the collector current Ic of the NPN transistor TR1 and the PNP transistor TR2 is used as a parameter.

  In the AC equivalent circuit OSC2 (eq_alt) of the oscillation device OSC2, as shown in FIG. 16, the collector current Ic = 0 as in the condition of the AC equivalent circuit OSC1 (eq_alt) of the oscillation device OSC1 shown in FIG. When 0.1 mA, the negative resistance Rbci = 10 kΩ (absolute value) (frequency f = 3 MHz at this time), and when the collector current Ic = 0.2 mA, the negative resistance Rbci = 13 kΩ (absolute value) , Frequency f = 4.3 MHz) and collector current Ic = 0.5 mA, negative resistance Rbci = 14 kΩ (absolute value) (frequency f = 6.4 MHz at this time), as shown in FIG. Compared to the negative resistance Rbci = 1.6 kΩ (absolute value) of the conventional oscillation device OSC100 and equivalent circuit OSC100 (eq) shown in FIGS. It is possible to have value.

<< Modification 1 of Embodiment 2 >>
FIG. 17 is an equivalent block diagram of the oscillation device according to the first modification of the second embodiment. As shown in FIG. 17, the oscillation device OSC2 (eq1) of Modification 1 of Embodiment 2 basically has the same configuration as that of the equivalent circuit OSC2 (eq) of Embodiment 2. The difference from the equivalent circuit OSC2 (eq) of the second embodiment is that the second impedance Z2 (shown in FIG. 11) is constituted by a capacitor C2a and an inductor L2a connected in series instead of the second capacitor C2. It is being done.

  Therefore, the negative resistance Rbci and reactance Cbci of the equivalent circuit OSC2 (eq1) of the first modification give the negative resistance Rbci and reactance Cbci of the equivalent circuit OSC2 (eq) of the second embodiment. Is obtained by substituting C2 shown in the equation (25).

図１８は、実施例２の変形例１の等価回路のシミュレーション結果を示す。当該シミュレーションは、実施例１の変形例１の条件と同様に、トランジスタの電流増幅率ｈｆｅ＝１００、キャリアのベース走行時間τＦ＝０．３ｎｓｅｃ、Ｒ４＝Ｒ５＝ＲＢ＝２０ｋΩ、Ｃ１＝２０ｐＦ、Ｃ２ａ＝１０ｐＦ、Ｌ２ａ＝１０μＨを条件としている。

FIG. 18 shows a simulation result of the equivalent circuit of the first modification of the second embodiment. In the simulation, similarly to the conditions of the first modification of the first embodiment, the transistor current amplification factor hfe = 100, the carrier base travel time τF = 0.3 nsec, R4 = R5 = RB = 20 kΩ, C1 = 20 pF, C2a = 10 pF and L2a = 10 μH.

  In the equivalent circuit OSC2 (eq1), as shown in FIG. 18, the negative resistance Rbci is 10 kΩ (absolute value) at the oscillation frequency f = 9 MHz, and 1.6 kΩ of the negative resistance Rbci of the conventional oscillation device OSC100. As a comparison, a larger value can be obtained. Further, as is clear from comparison with FIG. 16 showing the simulation result of the negative resistance Rbci of the equivalent circuit OSC2 (eq) of the second embodiment, the equivalent circuit OSC2 (eq) of the second embodiment (where the collector current Ic = In contrast to the fact that 0.5 mA) can oscillate at a frequency from 6 MHz to 100 MHz, the equivalent circuit OSC2 (eq1) of the first modification of the second embodiment can oscillate at a frequency from 8 MHz to 16 MHz. In addition, the equivalent circuit OSC2 (eq1) of the first modification of the second embodiment can perform stable oscillation in a narrow band as compared with the oscillation device OSC2 (eq) of the second embodiment.

<< Modification 2 of Embodiment 2 >>
FIG. 19 is an equivalent block diagram of the oscillation device according to the second modification of the second embodiment. As shown in FIG. 19, the oscillation device OSC2 (eq2) of the second modification of the second embodiment has basically the same configuration as the equivalent circuit OSC2 (eq) of the oscillation device OSC2 of the second embodiment. The difference from the equivalent circuit OSC2 (eq) of the second embodiment is that the second impedance Z2 (shown in FIG. 11) is constituted by a capacitor C2a and an inductor L2a connected in parallel instead of the second capacitor C2. It is being done.

  Therefore, the negative resistance Rbci and reactance Cbci of the oscillation device OSC2 (eq2) of the second modification give the negative resistance Rbci and reactance Cbci of the oscillation device OSC2 (eq) of the second embodiment. Is obtained by substituting C2 shown in equation (26).

図２０は、実施例２の変形例２の等価回路のシミュレーション結果を示す。当該シミュレーションは、変形例１の発振装置ＯＳＣ２（ｅｑ１）のそれと同様に、トランジスタの電流増幅率ｈｆｅ＝１００、キャリアのベース走行時間τＦ＝０．３ｎｓｅｃ、Ｒ４＝Ｒ５＝２０ｋΩ、Ｃ１＝２０ｐＦ、Ｃ２ａ＝１０ｐＦ、Ｌ２ａ＝１０μＨを条件としている。

FIG. 20 shows a simulation result of the equivalent circuit of the second modification of the second embodiment. The simulation is similar to that of the oscillation device OSC2 (eq1) of the first modification example. The transistor current amplification factor hfe = 100, the carrier base travel time τF = 0.3 nsec, R4 = R5 = 20 kΩ, C1 = 20 pF, C2a. = 10 pF and L2a = 10 μH.

  In the oscillation device OSC2 (eq2) of the second modification, as shown in FIG. 20, the negative resistance Rbci is 10 kΩ (absolute value) at the oscillation frequency f = 9 MHz, and the negative resistance Rbci of the conventional oscillation device OSC100. As compared with 1.6 kΩ, it can be set to a large value. Furthermore, as is clear from comparison with FIG. 20 that shows the simulation result of the negative resistance Rbci of the oscillation device OSC2 (eq1) of the modification 1, the oscillation device OSC2 (eq1) of the modification 1 has a frequency range from 8 MHz to 16 MHz. In contrast to being able to oscillate at a frequency, the equivalent circuit OSC2 (eq2) of the second modification can oscillate at a frequency from 6.5 MHz to 13 MHz, and the equivalent circuit OSC2 (eq2) of the second modification is As compared with the equivalent circuit OSC2 (eq1) of the first modification, stable oscillation can be performed in a narrower band.

1 is a block diagram illustrating a configuration of an oscillation device according to a first embodiment. FIG. 3 is an equivalent block diagram of the oscillation device according to the first embodiment. FIG. 3 is a diagram illustrating an AC equivalent circuit of the oscillation device according to the first embodiment. FIG. 3 is a diagram illustrating a specific circuit of the oscillation device according to the first embodiment. FIG. 6 is a diagram illustrating another bias circuit of the oscillation device according to the first embodiment. FIG. 6 is a diagram illustrating a simulation result of an AC equivalent circuit of the oscillation device according to the first embodiment. FIG. 6 is an equivalent block diagram of the oscillation device according to the first modification of the first embodiment. FIG. 6 is a diagram illustrating a simulation result of an equivalent circuit of the first modification of the first embodiment. FIG. 6 is an equivalent block diagram of an oscillation device according to a second modification of the first embodiment. FIG. 6 is a diagram illustrating a simulation result of an equivalent circuit of a second modification of the first embodiment. Block diagram showing the configuration of the oscillation device of the second embodiment FIG. 6 is an equivalent block diagram of the oscillation device according to the second embodiment. FIG. 6 is a diagram illustrating an AC equivalent circuit of the oscillation device according to the second embodiment. FIG. 6 is a diagram illustrating a specific circuit of the oscillation device according to the second embodiment. FIG. 10 is a diagram illustrating another bias circuit of the oscillation device according to the second embodiment. FIG. 10 is a diagram illustrating a simulation result of an AC equivalent circuit of the oscillation device according to the second embodiment. FIG. 6 is an equivalent block diagram of the oscillation device according to the first modification of the second embodiment. FIG. 10 is a diagram illustrating a simulation result of an equivalent circuit of a first modification of the second embodiment. FIG. 6 is an equivalent block diagram of an oscillation device according to a second modification of the second embodiment. FIG. 10 is a diagram illustrating a simulation result of an equivalent circuit of a second modification of the second embodiment. The figure which shows the structure of the conventional oscillation apparatus. The equivalent block diagram of the conventional oscillation apparatus. The figure which shows the equivalent circuit of the conventional oscillation apparatus. The figure which shows the simulation result of the conventional oscillation apparatus.

Explanation of symbols

  OSC1 (eq): Equivalent circuit of oscillation device, TR1: PNP transistor, TR2: NPN transistor, C1: first capacitor, C2: second capacitor, X: crystal resonator.

Claims (4)

A PNP transistor,
An NPN transistor;
A crystal unit,
A first capacitor;
A second capacitor;
The emitter of the PNP transistor is connected to a power supply potential;
The emitter of the NPN transistor is connected to a ground potential;
One end of the first capacitor is connected to the ground potential;
One end of the second capacitor is connected to the ground potential;
The base of the PNP transistor, the base of the NPN transistor, the other end of the first capacitor, and one end of the crystal resonator are connected to each other in an alternating manner,
An oscillating device, wherein the collector of the PNP transistor, the collector of the NPN transistor, the other end of the second capacitor, and the other end of the crystal resonator are connected to each other. A first resistor connected between the emitter of the PNP transistor and the power supply potential;
A second resistor connected between the collector and base of the PNP transistor;
A third capacitor connected between a base of the PNP transistor and a connection point between the other end of the first capacitor and one end of the crystal unit;
A third resistor connected between the emitter of the NPN transistor and the ground potential;
A fourth resistor connected between the collector and base of the NPN transistor;
2. The method according to claim 1, further comprising a fourth capacitor connected between a base of the NPN transistor and a connection point between the other end of the first capacitor and one end of the crystal resonator. 1. The oscillation device according to 1. An NPN transistor;
A PNP transistor,
A crystal unit,
A first capacitor;
A second capacitor;
A collector of the NPN transistor is connected to a power supply potential;
A collector of the PNP transistor is connected to a ground potential;
One end of the crystal unit is connected to the ground potential,
One end of the second capacitor is connected to the ground potential;
The base of the NPN transistor, the base of the PNP transistor, the other end of the crystal resonator, and one end of the first capacitor are connected to each other in an alternating manner,
An oscillation device, wherein the emitter of the NPN transistor, the emitter of the PNP transistor, the other end of the first capacitor, and the other end of the second capacitor are connected to each other. A first resistor connected between the collector of the NPN transistor and the power supply potential;
A second resistor connected between the collector and base of the NPN transistor;
A third capacitor connected between a base of the NPN transistor and a connection point between the other end of the crystal resonator and one end of the first capacitor;
A third resistor connected between the collector of the PNP transistor and the ground potential;
A fourth resistor connected between the collector and base of the PNP transistor;
And a fourth capacitor connected between the base of the PNP transistor, the other end of the crystal resonator, one end of the first capacitor, and a connection point of the base of the PNP transistor. The oscillation device according to claim 3.

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