JPS5829206A - Transistor amplifier - Google Patents

Abstract

PURPOSE:To eliminate distortion components due to the nonlinearity of an amplifying element, by applying the output of the 1st transistor (TR) with a voltage gain (n) to the 2nd TR through (n-1) units of P-N junction parts. CONSTITUTION:An amplifying circuit 2 includes a TRQ2, which is grounded at its emitter through a resistance RB, connected to a positive power source +B at its collector through a load resistance RA, and applied with a circuit input Vi at its base. An amplifying circuit 1 includes a TRQ1, which is provided with a Darlington-connected TRQ3; and the collector output VA of the TRQ2 is applied to its base. While RA/RB=2 , the voltage gain of the amplifying circuit 2 is set to 2 and the respective TRs are given the same characteristics to eliminate distortion components in the output VO of the amplifying circuit 1, thereby eliminating distortion.

Description

[Detailed description of the invention] The present invention relates to a transistor amplifier.

Transistor amplifiers include a current feedback type grounded amplifier circuit in which a resistor is connected to the transistor's terminals.
Such a transistor amplifier circuit 1 is shown in FIG. The terminal of the transistor Q is connected to the negative 1km-B via the emitter resistor R8, and the collector is connected to the collector load resistor R.
, is connected to the positive power supply 10BK. Input signal Vt
is added to the pace and derived from the collector as output v0.

h of the transistor Qi which is the amplifier element of the circuit 1 in FIG.
? If M is sufficiently large, the collector current Ic is different from the emitter current IH, and if this is Io, then Iom (Vi ``Vile) 7RB ---・-・
- (1) is established. Here, KVB, is the voltage between the pace and the construction of the transistor Qt.The output voltage Vo is expressed by the following equation.

Vo = + B −I o R□ −−==
”・(2) (from equations 1 and (2)) The following equation is obtained.

R,R.

vo-(+B--vi)+"Vnm, -1-(3)
11 I understand that it is R-shima. This is due to the non-linearity of the transistor, and the voltage VBjl across the pace emitter! Since there is a non-linear relationship with respect to 0, such an amplifier has an inherent life.

There is a method of providing negative Nl feedback to eliminate such distortion, but applying negative feedback causes a decrease in the enhancement, and it is necessary to use a large number of amplifying elements to obtain the required enhancement. .

An object of the present invention is to provide a transistor amplifier capable of removing distortion components caused by nonlinearity of an amplifier element with a simple circuit configuration.

The present invention will be explained below with reference to the drawings.

FIG. 82 is a circuit diagram showing the operating principle of the present invention, and the amplifier circuit 1 has the same configuration as the circuit in FIG.
This is a round model using an inversion tank circuit 2 at the front stage. Amplifying circuit 2#'i has a transistor Q*. The emitter of this transistor Q is grounded via a resistor RB, and the collector is connected to the positive power supply 1B via a noble lead resistor RA. When circuit power Vl is applied to the control electrode of the transistor Q, an output V is derived from the collector as an output electrode, and the control electrode input of the transistor Q1,
In other words, it is a pace input. Note that the positive power supply of the amplifier circuit 1 is connected to +B.

In this circuit configuration, the output VA of the front-stage amplification circuit 2 and the output vo of the rear-stage amplification circuit 1 are expressed by the following equations.

VA"+B-"' (Vi-vBm,) ++＊+
＋＋＊＋＋＋＋＋,'(d)RB The Myoho formula is obtained by formulas (3) and (4).

......----A5) Then, ζ, where transistors Q and Q are equal, iI
If it has f# property, for example, if it is formed on the same semiconductor chip, then the current ! , and Io are equal, the resistor RB and the resistor RB and 1. Because it is necessary to increase the amount of feedback by R1. RB Maro Q x
There is a need for 4.

In this way, the purpose of making the resistances RA and RB of the front-stage amplification circuit 2 equal is to make the amplification circuit 2 an amplification circuit with a voltage gain of 1, which makes it possible to remove distortion components. Become.

FIG. 3 is a circuit diagram showing another embodiment according to the operation principle of the present invention, in which N-channel junction field effect transistors are used as transistors Ql and Qm.

The circuit input Vi is applied to the gate, which is the control electrode of the transistor Q, and the drain is used as the output electrode,
Output V□ is output from the drain. The output signal is applied to the gate, which is the control electrode, of the transistor Q1, and the circuit output vo is derived from the drain, which is the output electrode.

By making the gate-source voltages VG8 of both transistors equal and making the resistors R4 and RB equal, the distortion component can be similarly removed from the output v0.

In the circuits of FIGS. 2 and 3 above, RA"RI
As I, the ratio of the output voltage to the input voltage of the front-stage amplifier circuit 2 is 1, that is, the voltage gain is 1.
Amplifier Fi according to the present invention shown below, this front stage amplification circuit 2
The voltage gain of the fourth
In the circuit of the illustrated embodiment, the voltage potential of the front-stage amplifying circuit 2 is set to 2.

That is, with Rm/RB = 2, a Darlington-connected transistor Q is provided to the transistor Q of the subsequent amplifier circuit 1, and the collector output V of the transistor Q is applied to the base of this transistor Qs. . Therefore, since the output vA passes through the two-stage PN junction of the base transistors of the transistors Qs and Q, the distortion term expressed by the equation +5) is expressed by the following equation.

If ζζ is R, /RB-2 and all transistors have the same characteristics, then vB□1=XVB, ,=V□.

Therefore, term (6) can be set to zero.

Generally, if the voltage gain of the front-stage amplifying circuit 2 is n (an integer greater than nij2) and R,/RB=n, the distortion can be reduced by using an eight-stage Darlington connection configuration for the transistors Q of the rear-stage middle circuit 1. Can be removed.

In other words, %'(''-1) stages of Darlington-connected transistors are provided between the base of the output transistor Q, and the transistor Q1 and the (n-1) Darlington-connected transistors are arranged in a Darlington configuration on a page. If the configuration is such that they are connected, the output (2) will be input to the base of the transistor Q via (0-1) PN junctions, and the predetermined purpose will be missed.

FIG. 5 shows the Darlington connection transistor Qs of FIG.
Alternatively, the diode DI is connected in the forward direction to the base current of the transistor Q, and the PN! of the diode D1 is connected in the forward direction to the base current of the transistor Q. Using the forward voltage VBMO of
If it is given as M/RB-Jm2, then k)★ component can be removed.

In the case of a general KRA/HB ratio B (an integer greater than nFi2), that is, the gain of the front amplifier 2 is set to n, and the output v
It is possible to input A to the base of the transistor Q through (n-1) PN junction elements and diodes.

In the above-mentioned 5J embodiment, bipolar of the same conductivity type or
Although a field effect transistor was used, FIG. 6 shows an example using a reverse conductivity type bipolar transistor. That is, an NPN (NPN) transistor is used for the transistor Q of the front-stage amplifier circuit 2, and the output voltage V is derived from the emitter of the transistor Q, forming an emitter follower circuit with a voltage gain of 1. Transistor in circuit l in the latter stage. Otori is P
NP) transistor is used, and the output vA of the front stage circuit 2
1) 5-space input, the resistance R],! The collector is connected to the positive power source 1B through the resistor R, and to the negative power source −B, Km through the resistor R, and the circuit output v0 is derived from the collector.

In this configuration, the following three equations hold true for i.

The following equation is obtained from the above equation (7).

@Mukuro Also in equation (8), by making the characteristics of both transistors small -Qs equal, it is possible to set VB=v□1 from K, and as a result, it is possible to eliminate the distortion component.

As described in detail above, according to the present invention, it is possible to remove distortion caused by nonlinearity of the amplifier element with a simple circuit configuration without any negative effects, and therefore, it is possible to improve the transistor amplifier width. You will get the equipment.

[Brief explanation of drawings]

@1 Is the diagram 1 of a conventional transistor amplifier? Schematic diagram showing il, drug 2 diagram, I! 3 and 6 are line diagrams showing the operating principle of the present invention, and Figures Is4 and 5- are circuit diagrams showing embodiments of the present invention, respectively. Explanation of symbols for important parts l --- Rear stage amplifying circuit 2 --- - First stage amplifying circuit Qt-Qt-'' --- Transistor Qs --- Darlington connection transistor DI.
--- Diode patent applicant Pioneer Corporation Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 -8j'''84

Claims (4)

[Claims] (1) A λ force is applied to the pace having a 9JIII transistor, and the ratio of the output voltage drawn to the collector of the 111 transistor to the front input torque is:
m (n is an integer of 2 or more), and the output led to the collector of the fa1 transistor is applied to the pace through (*-1) PN junctions. a second amplifier circuit having two transistors. (2) Said PN! The transistor amplifier according to claim 1, wherein the first coupling part is a diode. (3) The said PN
At the N junction, said Darlington! I continued (N-
1) The transistor amplifier according to claim 8, wherein the transistor and the second transistor are further connected in a Turlington connection. (4) The amplifier circuit N1 has a collector resistor and an emitter resistor connected to the collector and emitter of the transistor a11, respectively, and the ratio of the collector resistor to the emitter resistor is approximately Mil n. A transistor amplifier according to claim 1, 2, or 3.