JP2003258573A - Electronic circuit apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic circuit apparatus having an increased gain with less distortion. <P>SOLUTION: In this apparatus, emitter electrodes of third and fourth transistors 18, 19 being components of a voltage current conversion circuit 17 are connected to collector electrodes of first and second transistors 12, 13 being components a differential voltage current conversion circuit 11, resistors 22, 23 interconnect the collector electrodes of the first and second transistors 12, 13 and a prescribed current I2 not in excess of the operating current of the differential voltage current conversion circuit 11 is injected to the midpoint of the resistors. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a television receiver or C
The present invention relates to an electronic circuit device used in an amplifier circuit or a frequency conversion circuit of an electronic device such as an ATV.

[0002]

2. Description of the Related Art FIG. 7 shows a conventional differential amplifier circuit having a grounded base. The differential voltage-current conversion circuit 1 includes a pair of transistors 2 and 3 whose emitter electrodes are commonly connected. The transistor 2 and the transistor 3
An input differential voltage Vin is applied to the base electrode of, and the operating current I1 from the operating current source IA is supplied to the emitter electrode.

The common base connection circuit 4 has a pair of transistors 5 and 6 whose base electrodes are commonly connected.
And the emitter electrode of the transistor 5 is connected to the collector electrode of the transistor 2, and the emitter electrode of the transistor 6 is connected to the collector electrode of the transistor 3. Loads 7 and 8 are connected to the collector electrodes of the transistors 5 and 6, respectively.

Now, the voltage-current conversion conductance gm of the transistor 2 and the transistor 3 is expressed by the following equation with the operating current I1.

Gm = ΔI / ΔV = I1 / 4V _T V _T = kT / q where ΔI is the output current difference drawn from the collector electrodes of the transistors 2 and 3, and ΔV is the base electrode of the transistors 2 and 3. Input voltage difference, k is Boltzmann's constant, T is absolute temperature, q
Is the electron charge.

Since the base electrodes of the paired transistors 5 and 6 are commonly connected to the grounded base circuit 4 and operate as a grounded base circuit, the voltage gain Va of the amplifier shown in FIG. 7 has an input differential voltage of Vin and a load. If the resistance value of 7 and the load 8 is RL (RL1 = RL2), Va = Vout / Vin = gm.RL = I1 / 4V _T × R
It becomes L 2, and can be represented by the operating current I1, the resistance value RL of the load 7 or the load 8 and the physical constant q.

The grounded base effect of the grounded base circuit 4 is known as nullifying the Miller capacitance which degrades the frequency response. Specifically, the differential voltage-current conversion circuit 1
The collector voltage of transistor 2 and transistor 3 of
Since it is connected to the emitter electrodes of the transistor 5 and the transistor 6 of the base-grounded circuit 4, it hardly changes and prevents the gain reduction due to the negative feedback due to the capacitance between the base and collector of the transistor 2 and the transistor 3. You can

However, the collector DC voltage of the transistors 5 and 6 of the grounded base circuit 4 changes from the power supply voltage Vcc to R when the input differential voltage Vin = 0.
The operating current I1 is increased in order to increase the gain because the gain is decreased by L × 0.5 × I1.
It is necessary to increase the resistance value Rl, which naturally has a limit. Therefore, it is difficult to achieve both high input and high gain because of the non-linear characteristic of the voltage-current conversion that the differential amplifier circuit 1 originally has.

FIG. 8 is a characteristic diagram of input differential voltage versus output voltage of the above-mentioned conventional circuit. The output voltages Vout1 and Vout2 with respect to the input differential voltage Vin have apparently lost linearity above a certain voltage and below a certain voltage, and accurate amplification by multiplying the input differential signal by gain is performed. I can't expect.

FIG. 9 is a block diagram of an electronic circuit device obtained by improving the electronic circuit device of FIG. The difference from FIG. 1 is the same except that the emitter resistors 9 and 10 are connected to the emitter electrodes of the transistors 2 and 3 of the differential voltage-current conversion circuit 1. The linearity is maintained by inserting the emitter resistor 9 and the emitter resistor 10 and reducing the gain.

As can be seen from FIG. 10, the input differential voltage V
It can be seen that the output voltages Vout1 and Vout2 for in have improved linearity above a certain voltage and below a certain voltage. However, instead, it can be seen that the changes in the output voltages Vout1 and Vout2 with respect to the input differential voltage Vin are decreasing.

Voltage-current conversion conductance g at this time
m is gm = 1 / 2RE (4V _T / I1 << 2RE), and RE is the resistance value of the emitter resistors 9 and 10. Then, the voltage gain Va becomes Va = gm · RL = RL / 2RE, and it can be seen that the voltage gain Va is decreasing.

[0013]

As described above, the grounded base circuit connected to the differential voltage-current conversion circuit has the effect of nullifying the mirror capacitance that deteriorates the frequency response. As described above, since the collector voltage of each transistor of the differential voltage-current conversion circuit is connected to the emitter electrode of each transistor of the base-grounded circuit, it hardly changes and each collector voltage of the differential voltage-current conversion circuit does not change. It is possible to prevent the gain reduction due to the negative feedback due to the capacitance between the base and collector of the transistor.

However, the input DC voltage of the collector DC voltage of each transistor of the grounded base circuit is 0V.
In this case, since the power supply voltage Vcc is reduced by 0.5I1 × RL, there is a limit in increasing the gain, and due to the nonlinear characteristic of the voltage-current conversion originally possessed by the differential amplifier circuit, a large input is obtained. Also, it is difficult to achieve both high gain.

Therefore, the emitter resistance of each transistor of the differential voltage current conversion circuit is connected to the emitter resistance to insert the coupling resistance, and the gain is reduced to maintain the linearity. However, the change in the output voltage with respect to the input differential voltage is reduced, and the linearity cannot be maintained without reducing the gain.

[0016]

SUMMARY OF THE INVENTION The present invention provides an electronic circuit device that maintains linearity without reducing gain, and the present invention is a differential voltage-current conversion circuit comprising a first transistor and a second transistor. A base common connection circuit including a third transistor and a fourth transistor in which a base electrode is commonly connected and a load is connected to each collector electrode, and a common base connection circuit including a third transistor and a fourth transistor, the emitter electrode of the third transistor being a collector electrode of the first transistor And the emitter electrode of the fourth transistor is connected to the collector electrode of the second transistor, and the collector electrodes of the first transistor and the second transistor are connected by a resistor, and the differential voltage current is connected to the middle point of the resistor. Provided is an electronic circuit device including a current source that injects a constant current that does not exceed the operating current of a conversion circuit.

Also, the present invention provides an electronic circuit device which is an amplifier circuit for taking out an output signal amplified according to a potential difference between input differential signals applied to the first transistor and the second transistor of the differential voltage-current conversion circuit to a load. provide.

The present invention comprises a pair of first transistor and second transistor.
A first differential voltage-current conversion circuit including a transistor,
A load is connected to each collector electrode, and a second and a third voltage-current conversion circuit having a transistor whose emitter electrode is connected to the collector electrode of each transistor of the first differential voltage-current conversion circuit are provided. A current source in which the collector electrodes of the first transistor and the second transistor of the differential voltage-current conversion circuit are connected by a resistor, and a constant current which does not exceed the operating current of the differential voltage-current conversion circuit is injected at the midpoint of the resistor. There is provided an electronic circuit device including:

Further, according to the present invention, the input differential signal applied to the first differential voltage-current conversion circuit and the frequency-converted output according to the frequency of the input differential signal applied to the second and third voltage-current conversion circuits. Provided is an electronic circuit device which is a frequency conversion circuit for extracting a signal to a load.

The present invention includes a first transistor and a second transistor which form a pair.
A first differential voltage-current conversion circuit including a transistor,
A second differential voltage-current conversion circuit including a third transistor and a fifth transistor, each of which has an emitter electrode coupled thereto and a load connected to a collector electrode thereof, and a second differential voltage-current conversion circuit including an emitter electrode coupled to the collector electrode and a load coupled to the collector electrode thereof, respectively. A third differential voltage-current conversion circuit including four transistors and a sixth transistor, wherein the emitter electrodes of the third and fifth transistors are connected to the collector electrodes of the first transistor and the emitters of the fourth and sixth transistors are provided. An electrode connected to the collector electrode of the second transistor, a collector electrode of the first transistor and the second transistor connected by a resistor, and a base electrode of the third transistor and the fourth transistor and a base electrode of the fifth transistor and the sixth transistor. The base electrode is commonly connected, and the differential voltage-current conversion circuit is connected to the middle point of the resistance. To provide an electronic circuit device having a current source for injecting a constant current which does not exceed the operating current.

The present invention provides a first difference according to a frequency difference of input differential signals applied to the base electrodes of the third transistor and the fourth transistor and the base electrodes of the fifth transistor and the sixth transistor, respectively, which are commonly connected. Provided is an electronic circuit device which is a frequency conversion circuit for taking out an output signal obtained by frequency-converting an input differential signal applied to a dynamic voltage / current conversion circuit to a load.

The present invention provides a first differential according to a potential difference of an input differential signal applied to the base electrodes of the third transistor and the fourth transistor and the base electrodes of the fifth transistor and the sixth transistor, respectively, which are commonly connected. Provided is an electronic circuit device which is a variable gain amplifier circuit for taking out an output signal obtained by amplifying an input differential signal applied to a voltage-current conversion circuit to a load.

[0023]

DETAILED DESCRIPTION OF THE INVENTION An electronic circuit device of the present invention will be described with reference to FIGS.

FIG. 1 is a diagram of an electronic circuit device according to the present invention. A differential voltage-current conversion circuit 11 comprises a pair of a first transistor 12 and a second transistor 13, and the first transistor 12 and the second transistor 13 are provided. An input differential voltage Vin is applied to the base electrode of. Further, the emitter electrodes of the first transistor 12 and the second transistor 13 are coupled via a coupling resistor 14 and a coupling resistor 15, and a first current source IA for supplying an operating current I1 is connected to the midpoint thereof. . The emitter electrodes of the first transistor 12 and the second transistor 13 may be directly connected without a resistor and connected to the first current source IA.

The common base connection circuit 17 is composed of a third transistor 18 and a fourth transistor 19, which are paired with their base electrodes commonly connected and grounded.
The emitter electrode of 8 is connected to the collector electrode of the first transistor 12, and the emitter electrode of the fourth transistor 19 is connected to the collector electrode of the second transistor 13. The collector electrodes of the third transistor 18 and the fourth transistor 19 have loads 20 and 2
1 is connected to each.

Further, the collector electrode of the first transistor 12 to which the emitter electrode of the third transistor 18 is connected and the collector electrode of the second transistor 13 to which the emitter electrode of the fourth transistor 19 are connected are the resistor 22.
A second current source IB, which is coupled via a resistor 23 and injects a constant current I2 that does not exceed the operating current I1 of the differential voltage-current conversion circuit 11, is connected to the coupled midpoint.

The electronic circuit device of the present invention has the above-mentioned structure and has the load 20 depending on the differential potential Vin applied to the base electrode of the first transistor 12 of the differential voltage-current conversion circuit 11.
And an output voltage is obtained at the load 21. By the way, the current I2 of the second current source IB is injected into the first transistor 12 and the second transistor 23 of the differential voltage-current conversion circuit 11 via the resistors 22 and 23, respectively. The direct current flowing through 21 consequently decreases.

Therefore, the resistance value RL3 of the load 20 and the resistance value RL4 of the load 21 are made larger than the resistance value RL1 of the conventional load 7 and the resistance value RL2 of the load 8 shown in FIGS. Can be reduced to the same potential. In this case, the voltage gain Va is represented by Va = gm.RLa = RLa / 2RE, where RLa = RL3 = RL4, as in the above equation.

As shown in FIG. 2, the resistances RL3 and RL4 of the loads 20 and 21 are made larger than the load resistances RL1 and RL2 of the loads 7 and 8 of the conventional circuit to improve the gain as compared with FIG. be able to. Further, improvement in non-linearity can be seen in comparison with the input differential signal difference vs. output signal characteristic of the conventional electronic circuit device of FIG.

As shown in FIG. 3, the improvement of the non-linearity can be understood more concretely by comparing the input / output characteristics of the differential amplifier circuit 1. The horizontal axis represents the magnitude of the input differential signal, the vertical axis represents the magnitude of the output signal, the dotted line □ is the input / output characteristic of the conventional electronic circuit device of FIG. 7, and the dotted line × is the conventional electronic circuit device of FIG. I / O characteristics, solid line ⋄ is the input / output characteristics of the electronic circuit device of the present invention in FIG. The input / output characteristic of the electronic circuit device of the present invention is very small compared to the input / output characteristic of the conventional electronic circuit device of FIG. As shown, the distortion characteristics are improved. The input / output characteristic of the electronic circuit device is almost the same as the input / output characteristic of the conventional electronic circuit device shown in FIG. 9, but the voltage gain is large.

FIG. 4 is a block diagram showing an embodiment in which the electronic circuit device of the present invention is used in a frequency conversion circuit. The first differential voltage-current conversion circuit 22 is composed of a pair of the first transistor 12 and the second transistor 13 as described above, and the input differential signal f1 is applied to the base electrodes of the first transistor 12 and the second transistor 13. Is added. Also the first
Although the first current source I1 is directly connected to the emitter electrodes of the transistor 12 and the second transistor 13, the first current source I1 is connected to the first current source I1 via the coupling resistor 14 and the coupling resistor 15 as described above. You may.

The second differential voltage / current conversion circuit 33 includes the third differential voltage / current conversion circuit 33.
It consists of a transistor 18 and a fifth transistor 35,
The third differential voltage-current conversion circuit 34 includes the fourth transistor 19
And a sixth transistor 36, and loads 37 and 38 are connected to the collector electrodes of the fifth transistor 35 and the sixth transistor 36, respectively.

The base electrodes of the third transistor 18 and the fourth transistor 19 and the base electrodes of the fifth transistor 35 and the sixth transistor 36 are connected to each other.

The emitter electrodes of the third transistor 18 and the fifth transistor 35 are coupled to each other and connected to the collector electrode of the first transistor 12 of the first differential voltage-current conversion circuit 32. Similarly, the fourth transistor 19 and the sixth transistor
The emitter electrode of the transistor 36 is coupled and connected to the collector electrode of the second transistor 13 of the first differential voltage-current conversion circuit 32.

The collector electrode of the first transistor 12 and the collector electrode of the second transistor 13 are coupled via the resistors 22 and 23 as described above, and the first current source IA at the coupled middle point A second current source IB for injecting a constant current I2 that does not exceed the operating current I1 of the first differential voltage-current conversion circuit 32 is connected.

As shown in FIG. 5, the commonly connected third
An input differential signal of frequency f2 is applied to the base electrodes of the transistor 18 and the fourth transistor 19 and the base electrodes of the fifth transistor 35 and the sixth transistor 36. Also in this case, the current I2 from the second current source IB is applied to the first transistor 12 and the second transistor 13 via the resistors 22 and 23, and thus is applied to the base electrodes of the first transistor 12 and the second transistor 13. The frequency f1 + f2 which is the sum of the frequency f1 of the input differential signal shown in FIG.
And frequency difference f1-f2 frequency conversion FIG.
The output signal shown in (a) is taken out from the loads 20, 21 and the like without distortion.

FIG. 6 is a block diagram showing an embodiment in which the electronic circuit device of the present invention is used in a variable gain conversion circuit. The third transistor 18 and the fourth transistor 1 are commonly connected.
A signal having a DC potential difference Eo is applied to the base electrode of 9 and the base electrodes of the fifth transistor 35 and the sixth transistor 36. Therefore, as described above, the current I2 from the second current source IB is applied to the first transistor 12 and the second transistor 1
3 through the resistors 22 and 23, the third
By changing the ratio of the current distribution of the DC potential difference applied to the base electrodes of the transistor 18 and the fourth transistor 19 and the base electrodes of the fifth transistor 35 and the sixth transistor 36, there is no distortion in which the gain is changed from the loads 20 and 21. A large output signal can be taken out and used as a variable gain amplifier circuit.

[0038]

According to the electronic circuit device of the present invention, the second differential voltage conversion circuit is formed by the first differential voltage current conversion circuit having the first transistor and the second transistor whose base electrodes are commonly connected. The emitter electrodes of the third transistor and the fourth transistor are connected to the collector electrodes of the first and second transistors, respectively, and the first transistor and the second transistor are connected.
Since the collector electrode of the transistor is connected by a resistor and a constant current that does not exceed the operating current of the differential voltage-current conversion circuit is injected at the middle point of the resistor, the DC potential flowing in the load can be reduced. Therefore, the load resistance can be increased accordingly. Therefore, it is possible to take out an output signal in which the gain is improved and the distortion is reduced by the amount that the resistance of the load is increased.

Also, when the electronic circuit device of the present invention is used in a frequency conversion circuit and a variable gain amplifier circuit, it is possible to take out an output signal with improved gain and reduced distortion as described above.

[Brief description of drawings]

FIG. 1 is a block diagram of an electronic circuit device of the present invention.

FIG. 2 is a characteristic diagram showing the relationship between the potential difference of the input differential signal and the output voltage of the electronic circuit device of the present invention.

FIG. 3 is a characteristic diagram showing the relationship between the magnitude of an input differential signal and the magnitude of an output signal of the electronic circuit device of the present invention and the related art.

FIG. 4 is a block diagram showing another embodiment of the electronic circuit device of the present invention.

5 is a waveform diagram of an output signal of the electronic circuit device of FIG. 4 according to the present invention.

FIG. 6 is a block diagram showing another embodiment of the electronic circuit device of the present invention.

FIG. 7 is a block diagram of a conventional electronic circuit device.

8 is a characteristic diagram showing the relationship between the potential difference of the input differential signal and the output voltage of the conventional electronic circuit device of FIG.

FIG. 9 is a block diagram showing another embodiment of the conventional electronic circuit device.

10 is a characteristic diagram showing a relationship between a potential difference of an input differential signal and an output voltage of the conventional electronic circuit device of FIG.

[Explanation of symbols]

11 Differential voltage-current conversion circuit 12 First transistor 13 Second transistor 14 Coupling resistance 15 Coupling resistance 17-base common connection circuit 18 Third transistor 19 Fourth transistor 20 load 21 load 22 Resistance 23 Resistance 32 first differential voltage-current conversion circuit 33 Second differential voltage-current conversion circuit 34 Third differential voltage-current conversion circuit 35 Fifth Transistor 36 sixth transistor IB current source

Continued front page    (72) Inventor Hitoshi Aizawa             1-1-1 Sakata, Oizumi-cho, Ora-gun, Gunma Prefecture             Sanyo LSI Design System Soft             Inside the corporation F term (reference) 5J066 AA01 AA12 CA21 CA35 FA01                       HA02 HA25 HA30 KA05 MA04                       MA17 MA21 ND01 ND11 ND22                       ND23 PD02 SA08 TA02 TA06                 5J090 AA01 AA12 CA21 CA35 FA01                       GN01 HA02 HA25 HA30 KA05                       MA04 MA17 MA21 SA08 TA02                       TA06                 5J500 AA01 AA12 AC21 AC35 AF01                       AH02 AH25 AH30 AK05 AM04                       AM17 AM21 AS08 AS09 AT02                       AT06 DN01 DN11 DN22 DN23                       DP02

Claims (7)

[Claims] 1. A differential voltage-current conversion circuit comprising a pair of a first transistor and a second transistor, and a third transistor and a fourth transistor in which a base electrode is commonly connected and a load is connected to each collector electrode. A base common connection circuit, the emitter electrode of the third transistor is connected to the collector electrode of the first transistor, the emitter electrode of the fourth transistor is connected to the collector electrode of the second transistor, and the first transistor is connected. And a collector electrode of a second transistor are connected by a resistor, and a current source for injecting a constant current that does not exceed the operating current of the differential voltage-current conversion circuit is provided at the middle point of the resistor. apparatus. 2. An amplifier circuit for extracting an output signal amplified from a load according to a potential difference between input differential signals applied to a first transistor and a second transistor of the differential voltage-current conversion circuit. Item 2. The electronic circuit device according to Item 1. 3. A first differential voltage-current conversion circuit comprising a pair of a first transistor and a second transistor, a load connected to each collector electrode, and each emitter electrode having a first differential voltage-current conversion circuit. First transistor and second
A second and a third voltage-current conversion circuit each having a transistor connected to the collector electrode of the transistor, wherein the collector electrodes of the first and second transistors of the first differential voltage-current conversion circuit are connected by a resistor. An electronic circuit device, wherein a current source for injecting a constant current that does not exceed an operating current of the first differential voltage-current conversion circuit is provided at a middle point of the resistor. 4. An output signal obtained by frequency-converting the input differential signal applied to the first differential voltage-current conversion circuit according to the frequency of the input differential signal applied to the second and third voltage-current conversion circuits. The electronic circuit device according to claim 3, wherein the electronic circuit device is a frequency conversion circuit to be extracted. 5. A first differential voltage-current conversion circuit comprising a pair of a first transistor and a second transistor, and a second differential comprising a third transistor and a fifth transistor whose loads are respectively connected to collector electrodes. A voltage-current conversion circuit; and a third differential voltage-current conversion circuit composed of a fourth transistor and a sixth transistor, each of which has a load connected to a collector electrode, the base electrode of the third transistor and the fourth transistor, and the third transistor. The 5th transistor and the base electrode of the 6th transistor are commonly connected to each other, the emitter electrodes of the 3rd and 5th transistors are connected to the collector electrode of the 1st transistor, and the emitter electrodes of the 4th and 6th transistors are connected to the 2nd The collector electrodes of the transistors, and the collector electrodes of the first and second transistors Connect anti electronic circuit apparatus characterized by providing a current source for injecting a constant current, wherein no more than the operating current of the first differential voltage-to-current conversion circuit to the midpoint of the resistor. 6. The first differential according to the frequency difference of the input differential signals applied to the base electrodes of the third transistor and the fourth transistor and the base electrodes of the fifth transistor and the sixth transistor, respectively, which are commonly connected to each other. The electronic circuit device according to claim 5, wherein the electronic circuit device is a frequency conversion circuit that takes out an output signal obtained by frequency-converting an input differential signal applied to the voltage-current conversion circuit to a load. 7. A first differential voltage according to a potential difference between input differential signals applied to the base electrodes of the third transistor and the fourth transistor and the base electrodes of the fifth transistor and the sixth transistor, respectively, which are commonly connected to each other. The electronic circuit device according to claim 5, wherein the electronic circuit device is a variable gain amplifier circuit that takes out an output signal obtained by amplifying an input differential signal applied to the current conversion circuit to a load.