JP2655279B2 - Collector negative feedback crystal oscillator - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crystal oscillator having an extremely small oscillation frequency variation with respect to a change in a power supply voltage and an ambient temperature.

[Problems to be solved by conventional technology and invention]

FIG. 1A shows a conventional emitter-follower type crystal oscillator.

Grounded collector with emitter-earth resistance R _E2 -10
Ω and base bleeder resistance are 100 kΩ and 100 kΩ, respectively, and a capacitance C ₁ ≒ 400 pF is connected between the emitter and base bleeder. This circuit oscillates on the principle of a negative resistance oscillator.

In this case, direct current into alternating current to be negative feedback is not performed also, The resistance R _E2 and also the R _B1 is varied as a variable resistor Δf / f (Vc) characteristic curve of the minimum value characteristic achieving Because of the inability to do so, etc., Δ
f / f (Vc) ≒ 2.8 × 10 ⁻⁶ (Vc = 20 to 40 V), which has a disadvantage that the oscillation frequency fluctuation rate is considerably large.

The present invention has achieved a crystal oscillator having a good Δf / f (Vc, Ta) characteristic by eliminating the above-mentioned disadvantages. (Hereinafter, the oscillation frequency fluctuation rate with respect to a change in power supply voltage is Δf / f (Vc), and the oscillation frequency fluctuation rate with respect to a change in ambient temperature is Δf / f (Tc
a), the result of both is denoted as Δf / f (Vc, Ta). [Means for Solving the Problems] The following is a detailed description with reference to the accompanying drawings, particularly, FIG. 2, FIG. 12, and FIG.

In the base input emitter output transistors 1 stage amplifier, connects the crystal oscillator and the resistor R _B1 between the base and ground, and connecting the resistor R _E2 and the capacitance C ₁ between the emitter and ground, between the power collector Connect the load resistor R _C , connect the resistor R _F between the collector and the base, and make the resistance R _F as small as possible as much as possible to easily oscillate and apply strong negative feedback of DC and AC from the collector to the base. And a collector negative feedback method emitter-follower type crystal oscillator characterized in that the values of the resistors R _F , R _B1 , and the capacitance C ₁ are selected such that the oscillation frequency fluctuation rate with respect to the power supply voltage change becomes a minimum value. It is related.

In a single-stage base-input / emitter-output transistor amplifier, a crystal oscillator and a resistor R are connected between the base and ground.
It connects the _B1, resistance between the emitter and ground R _E2 and the capacitance C ₁
Connected, a capacitor C ₂ is connected between the base and emitter, a resistor R _C is connected between the collector and the power supply, and a resistor R _F is connected between the collector and the base. , the resistance R _F and subjected to a strong negative feedback between the DC to the base and the AC from the collector as a smallest possible value, and also the resistance to the oscillation frequency variation rate is respectively minimum values for supply voltage variation R _B1, R _C, The present invention relates to a collector negative feedback method Colpitts type crystal oscillator characterized in that a value of capacitance C ₁ ≒ C ₂ is selected.

Further, the base input emitter output transistors 1 stage amplifier, and connects the capacitor C ₃ and the crystal oscillator in series between the base and the ground, also to connect a resistor R _B1 between the base and the ground, between the emitter and ground connects the resistor R _E2 and a capacitor C _1, to connect the capacitor C ₂ between the base and emitter, and a resistor R _C between the collector and the power supply, the resistance between the collector and base
And Setsu沿the R _F, easily the resistance R _F subjected to strong negative feedback between the DC to the base and the AC from the collector as possible small value as long as possible oscillation, and also the oscillation frequency variation rate with respect to changes in the supply voltage is respectively The resistance R _B1 ,
The present invention relates to a collector negative feedback clap type crystal oscillator characterized in that values of R _C and capacitance C ₁ ≒ C ₂ are selected.

(Operation)

The description will be made based on the embodiments shown in the attached drawings, in particular, FIG. 2, FIG. 12, and FIG.

 The operation of claim 1 will be described.

In FIG. 2, a resistor R _E2 and a capacitor C ₁ = 408 pF are connected between the emitter and the ground, a resistor R _B1 and a crystal oscillator are connected between the base and the ground, and a resistor R _C is connected between the collector power supply. And connect a resistor R _F between the collector and base.

FIG. 3A shows an equivalent circuit of the crystal resonator. FIG. 3 (b) shows an approximate equivalent circuit of the crystal resonator. FIG. 4A shows an equivalent circuit diagram of the crystal oscillator shown in FIG. This equivalent circuit of the crystal oscillator as seen on the left side than the a-a 'is and R _Q
Become a series of L _Q, the _{Z Q = R Q + jωL Q} ...... (1).

The impedance Z _i on the transistor circuit side as viewed from the right side of aa ′ is a series value of the negative resistance R _A and the input C _A , Where R _Q ≒ 75Ω, If any, resistance component becomes zero the circuit, the permanent vibration of L _Q and C _A is generated, i.e., the crystal oscillator is to oscillate.

(4) than _{^{ω 2 = 1 / L Q C}} A ∴f = 1 / 2π (L Q C A) is ^1/2 ... (5). f is the oscillation frequency. This formulas to improve the oscillation frequency stability it can be seen that it is necessary to suppress the variation of C _A particularly devising the transistor circuit.

FIG. 4 (b) shows that C ₁ when R _F is a parameter is X
Taken as the axis is a calculated value curve when the input resistor R _A and the input capacitance C _A taken in the Y-axis. C ₁ is only in the range of about 150pF~10000pF R _A is negative resistance.

In the vicinity of the optimum value 408pF of C _1, as the R _F is smaller | R _A | is small. With conventional negative resistance oscillators (emitter follower type, Colpitts type, clap type), there is a fear that oscillation may become impossible due to variations in elements and changes in parameters.
_RA was extremely large.

But rather R _F is in the present invention, has a main purpose to suppress the oscillation frequency variation rate by stabilizing the transistor circuit strongly subjected to negative feedback by R _C.

There is a question that oscillation may not be possible,
Rather, the negative feedback stabilizes the transistor circuit itself, and the oscillation frequency becomes extremely stable.

On the other hand, the input capacitance C _A rapidly increases with the increase of C _{1 when} C ₁ ≒ 150 pF or more. In the conventional emitter-follower type oscillator, the value of C _A When the transistor parameter varies greatly fluctuate the oscillation frequency due to variations in V _C fluctuates, when subjected to negative feedback as in the present invention circuit, C The fluctuation of _A can be suppressed, and as a result, the oscillation frequency is stabilized.

Figure 4 (c) is to account for changes in transistor parameters C _A, the change in C _A when V _C is changed to 24V~44V ΔC _A
Is a calculated value curve obtained by drawing ΔC _A / C _A specified by C _A at V _C = 32 V, with R _F on the abscissa indicating the amount of negative feedback.

As the negative feedback amount is large R _F is smaller [Delta] C _A / C _A is extremely small. _A large decrease in ΔC _A / C _A clearly improves the oscillation frequency stability from equation (5).

From this figure, it can be explained that the oscillation frequency fluctuation rate characteristic can be greatly improved by the negative feedback.

On the other hand, the collector load resistance R _C is experimentally set to R _C ≒ 11 kΩ so that Δf / f (V _C ) is minimized as shown in FIG.
Also subjected to the negative feedback between the DC and AC via the negative feedback resistor R _F to the base from the collector. Since FIG. 7 (Δf / f (V _C) characteristic curve) as R _F is small as shown in Δf / f (V _C) is small, as possible oscillation, R _F = 31.1 as possible smaller
5 kΩ.

When _RE2 is changed, as shown in FIG. 5, Δf / f
The (V _C ) characteristic curve shows a minimum value characteristic at around RE _E2 ≒ 5.578 kΩ. Further, when R _B1 is changed at R _E2 ≒ 5.578 kΩ, the Δf / f (V _C ) characteristic curve realizes a minimum value characteristic convex downward as shown in FIG. 6, and is minimized when R _B1 ≒ 27.208 kΩ. Value. Varying the C ₁ in this case, Δf / f (V _C) characteristic curve as shown in FIG. 8 is realized minimum value characteristic of the downward convex, the minimum value C ₁ = 408pF. By setting R _C = 10.911 kΩ, R _F = 31.15 kΩ, RE ₂ = 5.578 kΩ, R _B1 = 27.208 kΩ, and C ₁ = 408 pF, the Δf / f (V _C ) characteristic has a minimum value. The characteristics are shown in FIG. 10, and as shown in FIG. 10, Δf / f (V _C ) ≒ −1.4 × 10 ⁻⁸ (V _C = 24 to 44 V) Δf / f (T _a ) ≒ −5 × 10 ⁻⁸ (T _a = −5 to + 55 ° C.).

However, crystal oscillator and the capacitor C ₁ is experimented kept constant at room temperature. This is because the emphasis was on observing how much the effect of the change in each parameter of the transistor of the active element was reduced. Note that reference, the emitter-follower type crystal oscillator circuit of Figure first place are conventionally presented (a), was experimentally varied independently and R _E2 and R _B1, Δf / f (V _C ) It was not possible to obtain a minimum value characteristic curve whose characteristic is convex downward.

Therefore, it exhibited a relatively poor characteristic of about Δf / f (V _C ) ≒ 3 × 10 ⁻⁶ (V _C = 20 to 40 V).

As described above, in the present invention, the characteristic of the minimum value of Δf / f (V _C ) is realized by optimizing the values of R _C , R _F , R _E2 , R _B1 , and C ₁ to obtain Δf / f ( V _C, to reduce the T _a) characteristic, V _C and T _a Δf / f (V _C to changes in, T _a) to achieve a transistor emitter-follower type crystal oscillator where very small.

Furthermore, as shown in FIG. 11 (a), the collector capacitance _{C C, Δf / f (V} C) due to a change in _T ransition frequency f _T is changing in a positive direction, the emitter resistor r _e, the base resistance r _b change by Δf / f (V _C) it can be seen that are very small Δf / f (V _C) by offsetting each other changes in the negative direction. One curve has the same tendency as the measured value in the same industry digit. From this, the general agreement between the theory and the experimental values can be confirmed.

In this manner, by setting the negative feedback of the cross-current by R _F and R _C and the values of R _B1 and R _E2 to appropriate values, Δf / f (V _C ) is projected downward by the canceling action of the transistor parameters. Can be realized, and Δf / f (V _C , T _a ) can be made extremely small.

FIG. 11 (b) shows a simulation result when C ₁ = 300 pF. That by _{C C Δf / f (V C} ) is a positive resistance, r _e r, _b, according to _{f T Δf / f (V C} ) is negative, the difference therebetween is in the first curve. Here, 1 curve _{r e, C C, r b} , f
If all _T is considered to change with respect to V _C, 2 curves C _C, r _b, when only r _e a f _T as a fixed value has to be changed with respect to V _C, 3 curves likewise C _C only , 4 curves only r _b, 5 curve shows the case of five of only f _T.

In this case, the three curves by C _C become larger than the sum of the 2, 4, and 5 curves, and as a whole, one curve of the positive. In this case, Δf / f (V _C ) + 7 × 10 ^-8 (V _C = 24 to 44
V). And as shown in FIG. 11 (a), approximately equal the effect of both changes in the r _e, r _b and C _C, f _T in the vicinity of the minimum value, offsetting 2,4 curve and 3,5 Curve The effect appears remarkably and the Δf / f (V _C ) characteristic becomes flat, and Δf / f (V _C ) ≒ −
It will gradually show a small value of 1 × 10 ⁻⁸ (V _C = 24 to 44 V).

 The operation of claim 2 will be described.

In FIG. 12, C ₁・ 1131 pF
The between the emitter and the base, connecting the C ₂ ≒ 972pF, the a crystal oscillator between the base and ground and the resistor R _B1, the resistance R _E2 between the emitter and ground, a collector load resistor R _C, the collector-base Connect to resistor R _F. In this case, an oscillation frequency determining circuit including a crystal oscillator and two capacitors is positively fed back from the emitter to the base. As it can be easily inferred from FIG. 4, the input impedance of the amplifier viewed from _{a-a 'Z 11 = -R} A -jY A, (Y A = 1 / ωC A) (2) , and the input resistance (Negative Resistance) and the input capacitance in series.

Hence the negative resistance -R _A larger relative positive resistance component R _CX of the crystal vibrator-side since R _CX -R _A ≦ 0 ...... amplitude determining condition (3) is easily established, readily oscillate.

The collector load resistance R _C is determined experimentally as shown in FIG.
R _C ≒ 11kΩ so that f / f (V _C ) is minimized. Also subjected to the negative feedback between the DC and AC via the negative feedback resistor R _F to the base from the collector. Since FIG. 7 (Δf / f (V _C) characteristic curve) as R _F is smaller as shown in Δf / f (V _C) is small, as possible oscillation, and R _F ≒ 30.50kΩ as possible smaller . Also in this case, it is varied between the emitter and the ground resistance R _E2, since Δf / f (V _C) properties can not be obtained a minimum value characteristic of convex downward, in consideration of the stability index R _E2 ≒ 1
1kΩ. If R _E2 = 10.898kΩ and the base-to-earth resistance R _B1 is changed, the Δf / f (V _C ) characteristic curve realizes a minimum value characteristic with a downward convex as shown in Fig. 13. By setting R _B1 ≒ 27.42 kΩ, R _F = 30.50 kΩ, R _E2 = 10.898 kΩ, and R _B1 = 27.42 kΩ, the Δf / f (V _C ) characteristic shows the minimum value characteristic, and FIG. As shown, Δf / f (V _C ) ≒ 1.2 × 10 ⁻⁸ (V _C = 24 to 44 V) Δf / f (T _a ) ≒ −3 × 10 ⁻⁸ (T _a = −5 to 55 ° C.) High stability characteristics could be realized.

However, the frequency determination circuit composed of the crystal oscillator and the capacitors C ₁ and C ₂ is realized at a constant temperature at room temperature. This is because the emphasis was on observing how much the effect of the change in each parameter of the transistor of the active element was reduced. Note that reference, the Colpitts crystal oscillating circuit of FIG. 1 at which are conventionally presented (b), R _E2
And R _B1 were independently changed,
It was impossible to obtain a minimum value characteristic in which the Δf / f (V _C ) characteristic was convex downward.

Therefore, relatively poor characteristics such as Δf / f (V _C ) ≒ 2 × 10 ⁻⁶ (V _C = 24 to 44 V) were exhibited.

To reduce the Δf / f (V) characteristic, the capacitance C ₁
And it may be increasing the value of C ₂ It is known street.
However, when C ₁ and C ₂ are increased, the degree of attenuation (required amplification) increases, and oscillation tends to be difficult. Here, as long as oscillation occurs, C ₁ and C ₂ are made as large as possible, and C ₁ = 1131 pF and C ₂ = 972 pF.
f / f (V _C ) is slightly smaller.

Thus, in the present invention, R _C , R _F , R _E2 , R _B1 , C ₁ , C ₂
By optimizing the value, the minimum value characteristic of Δf / f (V _C ) is realized, the Δf / f (V _C , T _a ) characteristic is reduced, and V _C and
It is possible to realize a Transistor Colpitts type crystal oscillator where Δf / f (V _C , T _a ) is extremely small with respect to _a change in T _a .

Further, as shown in FIG. 11 (a), (this is a diagram in the case of an emitter-follower type crystal oscillator, it can be easily analogized that the same characteristics will be obtained in the Colpitts type. ) collector capacitance _{C C, Δf / f (V} C due to a change in the transition frequency f _T) is changing in a positive direction, the base resistance r _b, Δf / f due to the change in the emitter resistance r _e
(V _C ) changes in the negative direction to cancel each other, and Δ
It can be seen that f / f (V _C ) is extremely small. In this way, by making the negative feedback of the cross current by R _F and R _C and the values of R _B1 and R _E2 appropriate values, Δf / f (V _C ) is convex downward due to the canceling action of the transistor parameter. Can be realized, and Δf / f (V _C , T _a ) can be made extremely small.

This is shown in FIG. 11 (a) in the case of an emitter follower.
And FIG. 11 (b), which can be easily explained and proved sufficiently.

Therefore, the emitter follower type shown in FIG. 2, the collector type shown in FIG. 12, and the clap type shown in FIG. 15 have substantially the same resistance values, so that the DC circuit configuration is substantially the same.
Since the minimum value characteristics due to R _{B1 in} FIGS. 3 and 16 show the same tendency, the fact that Δf / f (V _C ) shows the minimum value characteristics that protrude downwards was proved by the emitter follower type. It is up to those who can easily guess what is caused by the cancellation of the transistor parameters.

 The operation of claim 3 will be described.

In FIG. 15, C ₁ = 1113 pF between the emitter and the ground.
Connect C ₂ = 972 pF between the emitter and base, connect C ₃ = 28.3 pF between the base and crystal, connect a crystal between C ₃ and ground, and connect a resistor R _B1 between base and ground. and the resistance R _E2 between the emitter and ground, connecting a collector load resistor R _C, and a collector-base resistance R _F. In this case, an oscillation frequency determination circuit including a crystal oscillator and three capacitors is positively fed back from the emitter to the base. In this case, as can be easily inferred from FIG. 4, the input impedance of the amplifier viewed from a-a 'is _{Z 11 = -R A -jY A,} (Y A = 1 / ωC A) (2) , and the Negative resistance and capacitance are in series.

Hence the negative resistance -R _A is larger than the positive resistance component R _CX of the crystal vibrator-side since R _CX -R _A ≦ 0 ...... amplitude determining condition (3) is easily established, readily oscillate.

On the other hand, the collector load resistance R _C is experimentally set to R _C ≒ 11 kΩ so that Δf / f (V _C ) is minimized as shown in FIG. Also subjected to the negative feedback between the DC and AC via the negative feedback resistor R _F to the base from the collector. Fig. 7 (Δf / f (V _C ) characteristic curve)
Since higher R _F is smaller Δf / f (V _C) is small, as shown in, as far as possible oscillation, R _F = 34.4 as possible smaller
8 kΩ.

Further, in this case, even if R _E2 is changed, the Δf / f (V _C ) characteristic cannot obtain the minimum value characteristic that is convex downward, so that R _E2 ≒ 11 kΩ in consideration of the stability index. Furthermore, R _E2 = 10.89
When the resistance R _B1 between the base and the ground is changed at 8 kΩ, the Δf / f (V _C ) characteristic curve realizes the minimum value characteristic of a downward convex as shown in FIG. 16, and R _B1 ≒ 40.61 The minimum value is at kΩ. By setting R _C -10.911 kΩ, R _F = 34.48 kΩ, R _E2 = 10.898 kΩ, and R _B1 = 40.61 kΩ, the Δf / f (V _C ) characteristic shows a minimum value characteristic. As shown in the figure, Δf / f (V _C ) ≒ 1 × 10 ⁻⁸ (V _C = 24 to 44 V), Δf / f (T _a ) ≒ 2.5 × 10 ⁻⁸ (T _a = −5 to + 55 ° C.) ) A high degree of high stability was achieved.

However, experiments were conducted with the frequency determination circuit composed of the crystal unit and the capacitors C ₁ , C ₂ and C ₃ kept constant at room temperature. This is because the emphasis was on observing how much the effect of the change in each parameter of the transistor of the active element was reduced. Note that reference, the clap type crystal oscillator circuit of FIG. 1 at which are conventionally presented (c), R _E2
And R _B1 were independently changed,
It has been impossible to obtain a minimum value characteristic curve in which the Δf / f (V _C ) characteristic is convex downward. Therefore, Δf / f (V _C ) ≒ 2.8 × 10 ^-6 (V _C
= 20-40V), which is relatively poor.

To reduce the Δf / f (V _C ) characteristic, the capacitance C ₁
And increase the value of C _2, it is well known that may be reduced to C _3. However, when C ₁ and C ₂ are increased and C ₃ is decreased, the attenuation (predetermined amplification) increases, and oscillation tends to be difficult. Here, as long as oscillation occurs,
C ₁ and C ₂ are made as large as possible and C ₃ is made small, so that C ₁ =
Δf / f because 1131pF, C ₂ = 972pF, C ₃ = 28.3pF
(V _C ) is slightly smaller.

Thus, in the present invention, R _C , R _F , R _E2 , R _B1 , C ₁ , C ₂ ,
By the optimal value C ₃ values, to realize a minimum value characteristic of _{Δf / f (V C),} Δf / f (V C, T a) characteristic is reduced, V _C
And _{T a Δf / f (V C} , T a) to a change in can be realized transistor Clapp type crystal oscillator at very small.

Further, as shown in FIG. 11 (a), (this is a diagram in the case of an emitter-follower type crystal oscillator, but it can be easily analogized that similar characteristics will be obtained in a clap type. ) C _C changes by Δf / f (V _C) is changing in a positive _{direction, r e, r b, Δf} / f (V C due to changes in f _T) is to cancel each other changes in the negative direction Δf / f (V _C )
Is extremely small. Thus, R _F , R _C
By setting the values of R _B1 and R _E2 to the appropriate values of the negative feedback of the cross-flow and the values of R _B1 and R _E2 , Δf / f (V _C ) realizes a minimum value characteristic convex downward by the offsetting action of the transistor parameters. Thus, Δf / f (V _C , T _a ) can be made extremely small.

〔Example〕

[1] A specific circuit configuration example of claim 1 will be described.

FIG. 2 shows an embodiment of the invention, in which a collector load resistance R _C = 10.911 kΩ, a negative feedback resistance R _F from the collector to the base R 31.15 kΩ, and a crystal oscillator (oscillation frequency of about 1 MHz) ) And a resistor R _B1 = 27.208 kΩ, and a transistor-emitter follower type crystal oscillator configured by connecting R _E2 = 5.578 kΩ and C ₁ = 408 pF between the emitter and the earth.

[2] A specific circuit configuration example according to claim 2 will be described.

FIG. 12 shows an embodiment of the present invention, in which the collector load resistance R _C = 10.911 kΩ, the negative feedback resistance R _F from the collector to the base = 30.50 kΩ, and a crystal oscillator (oscillation frequency of about 1 MHz) ) And resistor R _B1 = 27.42kΩ, Transistor Colpitts type crystal constructed by connecting R _E2 = 10.898kΩ and C ₁ = 113pF between emitter and ground and C ₂ = 972pF between emitter and base 2 illustrates an oscillator.

[3] An example of a specific circuit configuration example of claim 3 will be described.

FIG. 15 shows an embodiment of the present invention, in which the collector load resistance R _C = 10.911 kΩ, the negative feedback resistance R _F from the collector to the base = 34.48 kΩ, and a crystal oscillator (oscillation frequency of about 1 MHz) ) In series with C ₃ = 28.3 pF and in parallel with a resistor
Connect R _B1 = 40.61kΩ and R _E2 =
10.898kΩ and C ₁ = 1131pF, C ₂ = 972p between emitter and base
5 shows a transistor-clapping type crystal oscillator configured by connecting F.

Next, in [4] described below, the theory of the emitter-follower type crystal oscillator and the method of experimentally determining each element value are described, and it is shown that the Δf / f (V _C ) value substantially matches the theory and the experiment. At the same time, clarify the transistor parameters that affect Δf / f (V _C ). In addition, for the Colpitts-type and Clap-type crystal oscillators, a method of realizing the minimum value of the Δf / f (V _C ) characteristic by changing the resistance R _B1 between the base and the ground will be described. That is,
For the emitter follower type, Δf / f (V _C ≒ −1.4 × 10 ⁻⁸ (V _C
= 24 to 44 V), Δf / f (Ta) ≒ −5 to + 55 ° C.], and in the Colpitts type, Δf / f (V _C ) ≒ + 1.2 × 10 ⁻⁸ (V _C = 24 to
44V) 、 Δf / f (Ta) ≒ -3 × 10 ^-8 (Ta = -5 ゜ ～ + 55
° C), and for the clap type, Δf / f (V _C ) ≒ + 1.0 × 10
^-8 (V _C = 24 to 44 V), Δf / f (T _a ) ≒ −2.5 × 10 ^-8 (Ta =
−5 ° C. to + 55 ° C.), and fairly good characteristics are obtained.

[4] Theory of a crystal oscillator, a method of experimentally determining each element value, a method of realizing a minimum value of the Δf / f (V _C ) characteristic, etc. [4.1] Item 1. (Emitter-follower type crystal oscillator) [4.1.1] Features of Oscillation Circuit Configuration The present invention is an emitter-follower type crystal oscillator using a new configuration method that eliminates the above-mentioned disadvantages. The features of the circuit system as shown in FIG. 2, is connected to (1) only using one crystal oscillator, the capacitance C ₁ between the emitter and ground, crystal oscillator between the base and the ground . (2) Set the collector load resistance R _C to an appropriate value, and set the resistance R _F from the collector to the base.
Negative feedback of direct current and alternating current is applied via. (3) varying the emitter resistance R _E2 by Delta] f / f (Vc) is appropriate value R _E2 value so that the minimum value. (4) Base resistance R _B1
Changing the by Δf / f (Vc) is appropriate value R _B1 value so that the minimum value. (5) by changing the capacitance C ₁ Δf / f (V
c) is selected C ₁ value to a suitable value so that the minimum value. As a result, Δf / f (Vc) ≒ −1.4 × 10 ⁻⁸ (Vc = 24 to 44
V) and Δf / f (Ta) ≒ −5 × 10 ⁻⁸ (Ta = −5 to + 55 ° C.). Δf / f per 1V of power supply voltage is Δf
/ f / V = 7 × 10 ⁻¹⁰ / V, which is an extremely small value. This is equivalent to or higher in frequency stability than the conventionally known oscillation method. In the present invention, the principle of the proposed method is described, and a numerical analysis of the proposed circuit shown in FIG. 2 is performed to clarify the amplification transistor parameters that cause the oscillation frequency fluctuation rate.

[4.1.2] Theory [4.1.2-2] Oscillation Circuit FIG. 2 is a specific oscillation circuit showing an embodiment of the present invention.

R _C , R _F , R _B1 , R _E2 are the collector load resistance, the negative feedback resistance between the collector and base, the resistance between the base and ground,
A emitter-ground resistance, which is oscillated by connecting a crystal oscillator between the base and ground the capacitance C ₁ between the emitter and ground. Table 1 shows the circuit constants shown in FIG.

[4.1.2-2] Equivalent circuit of crystal oscillator In this section, an equivalent circuit of the crystal oscillator is derived. Generally, an equivalent circuit of a crystal oscillator is shown in FIG. Here, R _X , C _X , L _X , C _S , R _Q , and X _Q are equivalent resistance, equivalent capacitance, equivalent inductance, parallel capacitance, resistance and reactance of the crystal resonator. This can be equivalently converted as shown in FIG. 3 (b). That is, the impedance Z _{Q of the} crystal unit is Therefore Can say It is. Actual oscillation frequency f _OSC = 99909,912HZ (32V
c, + 25 ° C) into equations (5) and (6) yields R _Q ≒ 74.6
08Ω, L _Q ≒ 5,396 × 10 ^-4 H. Further, as shown in FIG. 3 (C), the following equation shows the real part and the imaginary part when the resistor _RB1 and the crystal unit are arranged in parallel.

Z _QR = R _CX + jY _X ... (7 ') _{However, R 5 = R B1 + R} Q [4 · 1 · 2 · -3] performed first analysis of the amplifier in this section derives an oscillation frequency determining conditions, determine the input impedance Z _11, yet a third view to (c) The analysis of the whole circuit loaded with the crystal oscillator circuit described above is performed to derive an oscillation frequency determination condition expression. Fig. 4 (a) shows an equivalent circuit diagram of the amplifier.
Shown in When the base input impedance is obtained from this, the following equation is obtained (the calculation equation is omitted due to space limitations).

Figure 4 (b) shows the characteristic curve of the R _F when a parameter, and the input resistance to the change of C ₁ (R _A) and the input capacitance (C _A).

Here, R _CX <| −R _A | (amplitude determination condition) (10) Y _X = Y _A (frequency determination condition) (11) is the oscillation condition. Equation (10) is easily satisfied.

Here, the equation (11) is obtained in detail, and the approximate consistency between the theory and the experiment is confirmed by computer simulation. When the equation (11) is calculated, the following equation is obtained.

A ₆ ω ¹⁴ + B ₆ ω ¹² + C ₆ ω ¹⁰ + D ₆ ω ⁸ + E ₆ ω ⁶ + F ₆ ω ⁴ + G _{6
^{ω 2 + H 6 = 0 ......}} (12) _{where, A 6 = - (I 5} 2 A 9 + A 7 F 9) B 6 = (I 5 2 B 9 -F 7 A 9 -G 9 A 7 -C 7 _{F 9) C 6 = - (} I 5 2 C 9 -F 7 B 9 + H 7 A 9 + H 9 A 7 + C 7 G 9 + F 9 B 7) D 6 = (I 5 2 D 9 -F 7 C 9 + H ^{_{7 B 9 -A 9 D 5 2}} -I 9 A 7 -C 7 H 9 -B 7 G 9) E 6 = (F 7 D 9 -I 5 2 E 9 -H 7 C 9 + B 9 D 5 2 - _{J 9 A 7 -I 9 C 7} -H 9 B 7) F 6 = (H 7 D 9 -F 7 E 9 -C 9 D 5 2 -K 9 A 7 -J 9 C 7 -I 9 B 7) _{G 6 = (D 9 D 5} 2 -H 7 E 9 -K 9 C 7 -J 9 B 7) H 6 = - (E 9 D 5 2 + K 9 B 7 ...... (13) _{A 7 = C C (A 5} I 5 -C 1 C e F 5), B 7 = (B 5 G 5 -D 5 C 5) C 7 = (D 5 C C C 1 C e + F 5 C 5 - _{A 5 G 5 C C -I 5} B 5) F 7 = (F 5 2 -2G 5 I 5), H 7 = (G 5 2 -2D 5 F 5) ...... (15) And However _{C C, C e, r e} , α, r b , respectively collector capacitance,
Emitter capacitance, emitter resistance, grounded base current gain,
Base resistance.

Equation (12) is the oscillation frequency determination condition equation. The above equation is difficult to solve analytically with a 14th order equation.

Therefore, by substituting specific circuit constants, the computer calculates the oscillation frequency ω (f), further clarifies the effects of circuit constants and transistor parameters on ω (f), and confirms the general agreement between theory and experiment. I do.

[4.1.2-2-4] Method of Determining Circuit Constants In this section, resistors R _E2 , R _B1 , R _F , R which are circuit components extremely closely related to Δf / f (V _C , T _a ) _The method of determining _C, etc. is examined and selected through experiments.

[4 · 1 · 2 · -4 -a] determined Figure 5 of R _E2 is empirically, varying _{R E2 Δf / f (V C} )
3 shows a characteristic curve. (R _F is kept as small as possible,
We are experimenting with R _B1 constant. 3.) A curve with a relatively sharp minimum is obtained as shown. With minimum value, R _E2 = 5,5
At 78 kΩ Δf / f (V _C ) 10−1.4 × 10 ^-8 (V _C = 24 to 44 V)
Becomes In addition, the + sign of the right curve indicates a curve in which Δf / f (V _C ) increases with the increase of V _C , and the − sign indicates the reverse. The sharp minimum value characteristic has a close relationship with the negative feedback resistor R _F, is also one of the main focus of the present invention. Note emitter-follower type where negative feedback resistor R _F is not shown in FIG. 1, Colpitts, in Clapp type crystal oscillator, R _E2 and R _B1
Were independently varied, but no minimum curve was obtained at all, and the Δf / f (V _C ) value was extremely large as described above, indicating poor characteristics.

[4.1.2--4-b] Determination of R _B1 FIG. 6 shows Δf / f (V _C ) when R _B1 is changed in the experiment.
3 shows a characteristic curve. (We are experimenting with R _F as small as possible. As shown, Δf /
f (V _C ) characteristic curve can be obtained. R _B1 = 2 at the minimum point
Δf / f (V _C ) = − 1.2 × 10 ^-8 (V _C = 24 to 44 V) at 7,208 kΩ
It is. The right curve is-and the left curve is +.

In Figures 5 and 6, Δf / f (V _C ) ≒ 1.4 × 10 ^-8 (V _C = 24 to 44
V) Selection range of R _E2 and R _B1 values to obtain the degree is about 70 to 220Ω
Therefore, it is relatively easy to fix the resistance value.

Determining a seventh diagram [4 · 1 · 2 · -4 -c] R F represents a a Δf / f (V _C) characteristic curve, varying R _F in the experimental (R _E2, R _B1 together constant I am experimenting as a value.) It can be seen that Δf / f (V _C) decreases rapidly with decreasing R _F as shown. Here, Δf / f (V _C ) ≒ 1.2 × 10 ^-8
R _F = 31.15 kΩ is determined so as to realize (V _C = 24 to 44 V).

[4.1.2-2-4-d] Determination of C ₁ The two curves in FIG. 8 show Δf / f when C ₁ is changed in the experiment.
(V _C ) shows the characteristic curve. _{(R E2, R B1, R} F are experiments as constant values, respectively.) Since the extremely small value in C ₁ ≒ 408pF as shown, determining a C ₁ ≒ 408pF.

At this time, Δf / f (V _C ) ≒ 1.2 × 10 ⁻⁸ (V _C = 24 to 44 V). Note that the collector load resistance R _C is selected to be R _C ≒ 11 kΩ (as shown in FIG. 9) by exhibiting a comparatively gentle minimum curve experimentally.

[4.1.3] Experimental Results FIG. 10 shows the results of measuring the Δf / f (V _C , T _a ) characteristics with the actual circuit of FIG. Δ for approximately 45% change in power supply voltage
f / f (V _C ) ≒ −1.4 × 10 ⁻⁸ (V _C = 24 to 44 V)
The oscillation frequency fluctuation is about 0.014Hz. Same trend with the theoretical value. Therefore, Δf / f per 1V of power supply voltage
Is Δf / f / V = 7 × 10 ⁻¹⁰ / v, which is an extremely small value. This value can be calculated by using a conventionally known transistor, collector-emitter capacitive oscillator, emitter-follower type, clap type, Colpitts type base-emitter, collector-emitter
Emitter-capacitance oscillator, divided feedback type, collector-emitter capacitance oscillator, AGC-applied clap type, base
Δf / f / V is 1/472 to 1/142, 1/94 to 1/28, 1/9 compared to emitter, collector-emitter capacitive oscillator, etc.
The value is about 1/8 smaller. From the viewpoint of the oscillation frequency stability, the reciprocal of Δf / f / V is a measure of the frequency stability.Therefore, the frequency stability of this circuit system is Compared to these, about 472 to 142 times, 94 to 28 times, and 9 to 8 times better stability characteristics are obtained, respectively. Table 2 shows Δf /
Indicates f / V.

Δf / f (T _a ) ≒ −5 × 1
It is about 0 ^-8 (Ta = -5 to + 55 ° C). However, the experiment was performed while keeping the crystal unit and the capacity constant at room temperature.

This is because the emphasis was on observing how much the effect of the change of each parameter of the transistor of the active element was reduced. Is as small as stability index S = ∂Ic / ∂Ico ≒ 2.2, also because is subjected to negative feedback crossflow by R _F is relatively stable to changes in ambient temperature.
It is very easy to make the circuit of the present invention an IC.

[4,1,4] Discussion In this section, using the above-mentioned frequency determination condition expression (12),
An oscillation frequency fluctuation rate characteristic curve with respect to a power supply voltage change is obtained using a computer. First, in FIG. 2, V _C is 24~44V
Then, a 14th-order equation of the equation (12) is created in consideration of a change in the transistor parameter due to a change in the voltage of each part of the transistor in the case of the change. This is converged by a computer to obtain an oscillation frequency f. In this case the circuit constants in Table 1 shown previously shall not be changed with respect to V _C.

While transistor parameters are increased or decreased in accordance with the V _C.
That emitter DC current I _E is according to the measured relative V _C
It changes from I _E = 1.668 mA (V _C = 44 V) to 0.873 mA (V _C = 24 V). Also, the DC voltage V _CB between the collector and base is 11.74V (4
4V _C ) to 6.5V (24V _C ). C _C ∝V _CB ^−1/3
Assume that R _e = kT · 10 ³ / e · I _E (mA) = 25.6Ω / I _E
(MA) obtained from the V _E as to calculate the r _e.

Here, k is Boltzmann's constant, T is absolute temperature, and e is electronic charge. In example _{V C = 32V, r e,} C C, measured values of α and f
_T, catalog value of r _b is a value shown in Table 3. These numerical values are substituted into equation (12), and convergence calculation is performed by Newton's method to obtain an oscillation frequency. Then V _C B32V, the oscillation frequency at Ta = 25 ℃ becomes f. _CS = 999867.7014HZ. At this time it is determined from the transition frequency f _T -I _E characteristic curve. Eleventh
FIG. 7A shows the measured value and the calculated value of Δf / f (V _C ). Calculated value _{(1) r e, C C} , r b, if all f _T is considered to change with respect to _{V C, (2) C C} , r b, only r _e a f _T as a fixed value V _C If a change against, (3) Similarly C _C
, (4) r _b only, and (5) f _T only. Δf / f (V _C ) by C _{C of} (3) and (5)
The curve of the by _{f T Δf / f (V C} ), are both rise curve, the sum of the two parties, according to r _b of by r _e of (2) Δf / f and (V _C) (4) The Δf / f (V _C ) curves are both descending curves, and the sum of the two cancels each other to reduce Δf / f (V _C ). The curve (1) and the measured value show the same tendency and almost the same value (see FIG. 10). From this, it was possible to confirm the general agreement between the theoretical value and the measured value. Therefore Δf / f (V _C) relative to the characteristic _{r e, C C, r b} , the strongest effect of f _T. That is, Δf / f (V _C ) is essentially Δr _e /
_{r e, ΔC C / C C} , Δf T / f T, and Δr _b / r _b, to be altered by the found. Thus V _C Delta] f / f characteristics for the emitter resistance, the collector capacitance, base resistance, was revealed that largely influenced by changes in transition frequency. Δf / f (V _C ) due to changes in R _E2 , R _B1 , C ₁
The sharp minimum characteristic curve of Δr _e / r _e , ΔC _C / C _C ,
Δr _b / r _b, that are effective by cancellation of Delta] f _T / f _T and the by Δf / f (V _C) characteristics revealed. In addition, as described above, since the variation width of R _B1 for realizing the minimum value has a margin, the design of the actual circuit is relatively easy.

Further 1 curve of Figure 8 is a theoretical value by a computer, shows the characteristic curve of Δf / f (V _C), varying the capacitance C _1. As shown in the figure, a sharp minimum value characteristic curve centered on C ₁ ≒ 404 pF is shown. Together with changes in C ₁ Δf / f
(V _C ) is increasing.

In addition, the calculated value and the measured value show moderate agreement, and both show a sharp minimum value characteristic curve. Incidentally, in the conventional circuit system shown in FIG. 1, it is impossible to obtain a minimum value characteristic curve theoretically or experimentally. Therefore, it has been proved theoretically and experimentally that the circuit configuration of the present invention is an excellent method for reducing Δf / f (V _C , T _a ).

The above-mentioned series of trends can be roughly analogized for the Colpitts-type and Clap-type crystal oscillators described below.

[4.2] Claim 2 (Colpitts crystal oscillator)
[4.2.1] Features and Actual Circuit of Oscillation Circuit Configuration The present invention is a Colpitts-type crystal oscillator using a new configuration method that eliminates the disadvantages of the above-described conventional method.

As shown in Fig. 12, the features of this circuit system are:
(1) A frequency determination circuit including one crystal oscillator and two capacitors is positively fed back from the emitter to the base. (2) The collector load resistance R _C is set to an appropriate value, and a cross-flow negative feedback is applied from the collector to the base via the resistance R _F. (3) The base resistance _RB1 value is selected. (4) The capacitances C ₁ and C ₂ are considerably increased to reduce Δf / f (V _C ).

[4 - 2,2] circuit constant determination method first collector load resistor R _C is a R _C ≒ 11Keiomega about from Figure 9. Next, the negative feedback resistor R _F for cross-flow from the collector to the base is determined to be R _F = 30.50 kΩ in the same manner as in FIG. Here, even if R _E2 is changed, no minimum value appears in the Δf / f (V _C ) characteristic. Therefore, in order to reduce the stability index S, it is determined that R _E2指数 10.898 kΩ. FIG. 13 is a constant value to show experimentally Δf / f (V _C) characteristic curve, varying R _B1 (R _F is as small as possible, experimenting with R _E2, R _C a constant value There.) As shown, a curve having a relatively sharp minimum value is obtained. Table 4 shows the circuit constants.

[4-2.3] Experimental Results FIG. 14 shows the results of measuring the Δf / f (V _C , T _a ) characteristics with the actual circuit of FIG. Δ for approximately 45% change in power supply voltage
f / f (V _C ) ≒ + 1.2 × 10 ⁻⁸ (V _C = 24 to 44 V) and the oscillation frequency fluctuation is about 0.012 Hz. Therefore, Δf / f per 1 V of the power supply voltage is Δf / f / V = 6 × 10 ⁻¹⁰ / V, which is Δf / f / V compared with the conventionally known oscillation method.
Are smaller values by about 1/550 to 1/165, 1/109 to 1/32, and 1/10 to 1/9, respectively. Generally, the reciprocal of Δf / f / V is a measure of the frequency stability, so the frequency stability of this circuit system is about 550 to 165 times, Up to 32 times and 10 to 9 times better stability characteristics are obtained.

Δf / f (T _a ) ≒ −3 × 1 against changes in ambient temperature
0 ^-8 (T _a = −5 to + 55 ° C.). However, the experiment was performed while keeping the crystal unit and the capacitance constant at room temperature. This is because the emphasis was on observing how much the effect of the change in the transistor parameter of the active element was reduced. It is as small as stability index _{S = ∂I C / ∂I CO ≒} 1.8, also because is subjected to negative feedback crossflow by R _F is relatively stable.

Incidentally, as shown in Fig. 1 (b), at Colpitts quartz oscillator so-called conventional system where no negative feedback crossflow by R _F to the base from the collector, experimentally and R _E2 and R _B1 As a result of measuring the Δf / f (V _C ) characteristic while changing the characteristic, no minimum value characteristic curve was obtained.

Therefore, it has just been demonstrated that the circuit configuration of the present invention is an excellent method for reducing Δf / f (V _C , T _a ).

[4.3] Regarding claim 3 (clapping type crystal oscillator) [4.3.1] Features and actual circuit of oscillation circuit configuration The present invention provides a clap by a new configuration method which eliminates the above-mentioned disadvantages of the conventional method. Shaped crystal oscillator. As shown in FIG. 15, the features of this circuit system are (1) crystal oscillator 1
A frequency determination circuit consisting of three capacitors and three capacitors is positively fed back from the emitter to the base. (2) Collector load resistance R _C
Is set to an appropriate value, and negative feedback of cross-current is applied from the collector to the base via the resistor R _F. (3) The value of R _B1 is selected by changing the base resistance R _B1 so that the Δf / f (V _C ) characteristic becomes a minimum value. (4) Make the capacitances C ₁ and C ₂ considerably large,
_{The three} values are considerably reduced to reduce Δf / f (V _C ).

[4 - 3,2] circuit constant determination method first collector load resistor R _C is a R _C ≒ 11Keiomega about from Figure 9. Next, the negative feedback resistor R _F for cross-flow from the collector to the base is determined as R _F = 34.48 kΩ in the same manner as in FIG. Here the minimum value does not appear to Δf / f (V _C) characteristics by changing the R _E2. Therefore, to reduce the stability index S, R _E2 ≒ 1
Decide to be 0.898kΩ. Next, when R _B1 is changed, Δf / f (V _C )
The characteristic is a minimum value curve as shown in Fig. 16 ( _RF is kept as small as possible and a constant value is set, and experiments are performed with R _E2 and R _C being constant values). As shown, Δf / f (V _C ) ≒ 1.0 × 10 ^-8
Since the allowable range of R _B1 for obtaining (V _C = 24 to 44 V) is 1400Ω, the design of the actual circuit is relatively easy. Table 5 shows the circuit constants.

[4-3,3] Experimental Results FIG. 17 shows the results of measuring the Δf / f (V _C , T _a ) characteristics using the experimental circuit of FIG. Δ for approximately 45% change in power supply voltage
f / f (V _C ) ≒ + 1.0 × 10 ⁻⁸ (V _C = 24 to 44 V) and the oscillation frequency fluctuation is about 0.01 Hz. Therefore the power supply voltage
Δf / f per 1V is Δf / f / V = 5 × 10 ⁻¹⁰ / V, and this value is 1/660 to 1/660 of Δf / f / V, respectively, as compared with a conventionally known oscillation method. 198, 1/131 to 1/39 and 1/12 to 1/11 are smaller values. From the viewpoint of the oscillation frequency stability, the reciprocal of Δf / f / V is a measure of the frequency stability. 660-198 each
Good stability characteristics are obtained, ie, 131-39 times and 12-11 times. Table 2 shows Δf / f / V per 1 V of the power supply voltage in each document.

For the change in ambient temperature, Δf / f (T _a ) ≒ −2.5
× 10 ⁻⁸ (T _a = −5 to + 55 ° C.). However, the experiment was performed while keeping the crystal unit and the capacity constant at room temperature.

This is because the emphasis was on observing how much the effect of the change of each parameter of the transistor of the active element was reduced. It is as small as stability index _{S = ∂I C / ∂I CO ≒} 2.0, also because is subjected to negative feedback crossflow by R _F is relatively stable to changes in ambient temperature.
It is very good to make the circuit of the present invention an IC.

Incidentally, as shown in FIG. 1 (c), the Clapp type crystal oscillator according to a so-called conventional system where no negative feedback crossflow by R _F to the base from the collector, R _E2 and R _B1
As a result of measurement of the Δf / f (V _C ) characteristics by experimentally changing the above, no minimum value characteristic curve was obtained.

Therefore, it has just been demonstrated that the circuit configuration of the present invention is an excellent method for reducing Δf / f (V _C , T _a ).

〔The invention's effect〕

 The effect of claim 1 will be described.

In the emitter-follower type crystal oscillator configured as described above, the negative feedback of the cross current is applied from the collector to the base via the resistors R _C and R _F and the Δf / f (V _C ) characteristic curve is convex downward. The emitter-to-earth resistance R _E2 and the base-to-earth resistance R _B1 are selected so as to realize the minimum value characteristic of, so the Δf / f (V _C , T _a ) characteristic is extremely small. As a result, a transistor-emitter follower-type crystal oscillator having an oscillation frequency fluctuation rate with respect to changes in the power supply voltage and the ambient temperature, which is extremely smaller than that of the conventional crystal oscillator, and having good frequency stability can be realized.

 The effect of claim 2 will be described.

Or in the Colpitts oscillator configured as described, the resistance to the base than the collector R _C, the negative feedback of crossflow through the R _F applied, relatively large _{R E2, Δf / f (V} C) Characteristics Since the base-to-earth resistance R _B1 was selected to be an appropriate value so that the curve realized the minimum value characteristic with a convex downward, Δf / f
Since the (V _C , T _a ) characteristics are extremely small, the oscillation frequency fluctuation rate with respect to changes in power supply voltage and ambient temperature is extremely smaller than that of conventional crystal oscillators, and the transistor Colpitts type has excellent frequency stability. It becomes a crystal oscillator.

 The effect of claim 3 will be described.

In the clap crystal oscillator configured as described above, cross-flow negative feedback is performed from the collector to the base via the resistors R _C and R _F to make R _E2 a relatively large value, and Δf / f (V _C )
Since the base-to-earth resistance R _B1 was selected to be an appropriate value so that the characteristic curve realized a downwardly convex minimum value characteristic, Δf / f
Since the (V _C , T _a ) characteristics are extremely small, the oscillation frequency fluctuation rate with respect to changes in power supply voltage and ambient temperature is extremely smaller than that of conventional crystal oscillators, and the transistor clap type has excellent frequency stability. It becomes a crystal oscillator.

[Brief description of the drawings]

1 (a), 1 (b) and 1 (c) are circuit diagrams showing an example of a transistor crystal oscillator. FIG. 2 is a specific circuit diagram showing one embodiment of the present invention. 3 (a), (b), and (c) are diagrams showing equivalent circuits of a crystal resonator. FIG. 4 (a) is a diagram showing an AC equivalent circuit of FIG. FIG. 4B is a diagram showing a base input impedance. FIG. 5 is a diagram showing an oscillation frequency fluctuation rate characteristic curve with respect to a resistor _RE2 . FIG. 6 is a diagram showing an oscillation frequency fluctuation rate characteristic curve with respect to a resistor _RB1 . Figure 7 is a diagram illustrating an oscillation frequency variation rate characteristic curve for the resistor R _F. Figure 8 is a diagram illustrating an oscillation frequency variation rate characteristic curve for capacitance C _1. FIG. 9 is a diagram showing four curved lines of oscillation frequency fluctuation characteristics with respect to the resistance _RC . FIG. 10 is a diagram showing an oscillation frequency fluctuation rate characteristic of the circuit shown in FIG. 2 with respect to a change in a power supply voltage and an ambient temperature. 11 (a) and 11 (b) are diagrams showing oscillation frequency fluctuation rate characteristics of the circuit shown in FIG. 2 with respect to a change in power supply voltage. FIG. 12 is a specific circuit diagram showing one embodiment of the present invention. FIG. 13 is a diagram showing an oscillation frequency fluctuation rate characteristic curve with respect to a resistor _RB1 . FIG. 14 is a diagram showing oscillation frequency fluctuation rate characteristics of the circuit shown in FIG. 12 with respect to a change in power supply voltage and ambient temperature. FIG. 15 is a specific circuit diagram showing one embodiment of the present invention. FIG. 16 is a diagram showing an oscillation frequency fluctuation rate characteristic curve with respect to a resistor _RB1 . FIG. 17 is a diagram showing the oscillation frequency fluctuation rate characteristics of the circuit shown in FIG. 15 with respect to changes in the power supply voltage and the ambient temperature. FIG. 18 is a diagram showing circuit constants of the circuit shown in FIG. 2 and constants of the crystal unit. FIG. 19 is a diagram showing an oscillation frequency variation rate value per 1 V of power supply voltage of each conventionally known transistor crystal oscillator. FIG. 20 is a diagram showing a transistor parameter value when V _C = 32 V in the circuit shown in FIG. 2; FIG. 21 is a diagram showing circuit constants and crystal oscillator constants of the circuit shown in FIG. FIG. 22 is a diagram showing circuit constants and crystal oscillator constants of the circuit shown in FIG.

Claims (3)

(57) [Claims] 1. A base input / emitter output type transistor 1.
In a stage amplifier, a crystal oscillator and a resistor _RB1 are connected between the base and ground, and a resistor _RE2 and a capacitor are connected between the emitter and ground.
Connecting the C _1, to connect the load resistor R _C between power collector, base than the collector as connecting a resistor R _F between the collector and base, easily possible small value resistor R _F in as much as possible oscillation The values of the resistors R _F , R _B1 , R _C , and the capacitance C ₁ are selected so that strong negative feedback of direct current and alternating current is applied and the oscillation frequency fluctuation rate with respect to the power supply voltage change becomes a minimum value. A collector negative feedback method emitter-follower type crystal oscillator characterized by the following. 2. A base input / emitter output type transistor 1.
In a stage amplifier, a crystal oscillator and a resistor _RB1 are connected between the base and ground, and a resistor _RE2 and a capacitor are connected between the emitter and ground.
Connecting the C _1, to connect the capacitor C ₂ between the base and emitter,
A resistor R _C is connected between the collector and the power supply, and a resistor R _F is connected between the collector and the base.In this case, as long as oscillation is easily possible, the resistance R _F should be as small as possible and the DC and AC The collector is characterized in that the values of the resistors R _B1 , R _C , and the capacitance C ₁ ≒ C ₂ are selected so that a strong negative feedback is provided and the oscillation frequency fluctuation rate with respect to the power supply voltage change becomes a minimum value. Negative feedback method Colpitts type crystal oscillator. 3. A base input / emitter output type transistor 1.
In stage amplifier, and it connects the capacitor C ₃ and the crystal oscillator in series between the base and ground and between the base and the ground resistance R
Connect the _B1, connecting the resistor R _E2 and the capacitance C ₁ between the emitter and ground, and connecting a capacitor C ₂ between the base and emitter, and a resistor R _C between the collector and the power supply, the collector-base resistor R _F in the resistance R _F connects easily as possible oscillation
Apply strong negative feedback of DC and AC from the collector to the base as small as possible, and also set the resistance so that the oscillation frequency fluctuation rate with respect to the power supply voltage change becomes the minimum value.
A collector negative feedback clap type crystal oscillator characterized by selecting values of R _B1 , R _C , and capacitance C ₁ ≒ C ₂ .