JPS6141211A - Nonlinear output compensation circuit - Google Patents

Abstract

PURPOSE:To ensure compensation of a nonlinear part of an amplifier, etc. with no negative feedback of output, by having the symmetrical connection between a pair of transistors Tr and supplying the symmetrical input voltage having their levels changing in two steps to the bases of said Tr. CONSTITUTION:The collectors and emitters of npn Trs 2 and 4 are connected to each other. A control voltage signal Vi 1 whose level changes in two steps is supplied to a base input terminal 14. While a control voltage signal Vi 2 symmetrical to the signal Vi 1 is supplied to a base input terminal 16. Thus a V- shaped part 22 where the current value is reduced suddenly at a period 21 when both signals Vi 1 and Vi 2 cross is formed to the waveform of a collector current ID. Thus a nonlinear part of an amplifier circuit, etc. is improved by making use of such output waveform characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a nonlinear output compensation circuit for improving the nonlinear output of an amplifier and switching circuit using diodes and transistors to linear output.

[Conventional technology]

In amplifiers, switching circuits, etc. that use diodes and transistors, nonlinear parts are not used, or nonlinearity at the start of conduction and near saturation of semiconductors is improved, unless the nonlinearity does not affect the purpose of the circuit. To achieve this, it is common to provide negative feedback to the amplified output to improve linearity.

[Problem that the invention seeks to solve]

In the method of improving linearity by negative feedback of the output, the input is amplified and output, so as signal processing speeds up, there are problems such as phase shift and, in extreme cases, circuit oscillation.
Especially when linearity is required from non-conduction to saturation beyond the operating range of the semiconductor, and high speed is also required.

Linearity must be improved without negative feedback of the output to the input side. The present invention aims to solve the above problems.

[Means to solve problems]

In order to achieve the above object, the present invention provides a structure in which the pair of transistors 2 and 4 are arranged symmetrically.
The collectors and emitters of the transistors 2 and 4 are connected to each other, and a pair of symmetrical voltage signals whose levels change in two steps is applied to the bases of the transistors 2 and 4, and when the voltage signals cross, the transistors 2 and 4 This is characterized in that the collector current changes in a seven-figure pattern.

[Effect]

In the above configuration, one voltage signal Vj1 of a pair of mutually symmetrical voltage signals V i 1 and V i 2 whose level changes in two steps is applied to the base of one of the pair of transistors 2 and 4. However, when the other voltage signal V i 2 of the pair of voltage signals is applied to the base of the other of the transistors 2 and 4, when the pair of voltage signals V i 1 and V i 2 intersect , the collector currents of the transistors 2 and 4 change in a V-shape. Therefore, by adding this V-shaped output to the non-linear portion of the output of a switching circuit or the like, the non-linear portion can be improved.

〔Example〕

The configuration of the present invention will be described in detail below based on embodiments shown in the accompanying drawings.

Figures 1a and 1b show a nonlinear compensation circuit. At a, the respective collectors of the two NPN transistors 2 and 4 are connected to each other, and the NPN transistors 2 and 4 are connected to each other.
The respective emitters of are connected to each other. Similarly, in the compensation circuit shown in b, the collectors and emitters of a pair of PNP transistors 6.8 are connected to each other. a,
t) respectively two transistors 2 and 4 and 6 and 8
are symmetrically connected to each other. In the figure, 10.12 is a reference voltage supply terminal, and 14, 16, 18.20 are input terminals. Base input terminal 14 of each of the compensation circuits a and b
．． When the control voltage signal 11 whose level changes in two steps as shown in FIG. , b, the waveform of IU shows a V-shaped portion 2 in which the current value suddenly decreases in a V-shape at the time 21 when the above-mentioned Vi1 and Vi2 intersect, as shown in Fig. 2c.
2°24 is formed. Using this output waveform characteristic,
Non-linear parts of amplifiers and switching circuits can be improved. This principle will be explained with reference to FIGS. 11 and 12. P to the line 26 through which current flows into the load resistor RL.
Connect a compensation circuit consisting of an NP transistor.

NP to the line 28 from which current flows to the load resistance RL.
When a compensation circuit a consisting of N transistors is connected, and if the current flowing through the line 26 is IP and the current flowing through the line 28 is IN, then (I P - I N) RL=Vou Therefore,
When TN changes into a 7-figure shape, V out is as shown in Figure 12a.
When the IP changes into an inverted V shape as shown in FIG. 12, V out changes into a seven character shape as shown in FIG. 12. From this, it can be understood that by appropriately connecting the NPN transistor type compensation circuit and the PNP transistor type compensation circuit to the load resistor, a V-shaped output voltage and an inverted V-shaped output voltage can be obtained. Amplify this output voltage,
By adding it to a non-linear part of a switching circuit, the non-linear part can be improved into a straight line.

The voltage signals Vil and Vi2 can be generated by a differential switch circuit shown in FIG.

In FIG. 3, 30 and 32 are NPN transistors, which are symmetrically connected. 34 is an NPN transistor constituting a constant current circuit, and 36 and 38 are collector power supplies.

A reference voltage V'SI is applied to the base of the transistor 32. In the above configuration, when the input voltage ■'i shown in FIG. 4 is supplied to the base of transistor 30, voltage signals Vil and V i 2 are generated on lines 40 and 42. The intersection point X between Vil and V i 2 can be set at a desired time by adjusting the level of the reference voltage V'SI. Next, an example of improving the nonlinearity of a differential switching circuit using an NPN transistor type non-linear linear compensation circuit will be described with reference to FIG.

In the figure, NPN transistors 44 and 46 constitute a differential switching circuit, and a reference voltage VSI is applied to the base of the transistor 46. Terminals 48,50 are connected to the collector power supply. When the input voltage Vi shown in FIG. 6 is input to the base of the transistor 2, the V-shaped compensation characteristic of the nonlinear compensation circuit 52 causes the transistor 44.
The nonlinearity of the parts 54 and 56 of the collector current waveforms a and b of No. 6 is improved, and the parts change linearly.

Next, we will explain an embodiment in which the non-linearity of the output of the remainder output conversion circuit 58 shown in FIG. It is composed of a switch circuit, and the differential switch circuit is composed of a pair of NPN transistors. A reference potential Vs is applied to the base of one transistor 62 of a pair of NPN transistors 2.64. This reference potential Vs is the line L
This is set by a large number of dividing resistors 66 provided in the. The output lines of the plurality of differential switch circuits are connected to a limited constant current circuit 68.

The output line of the circuit 68 always has a constant current, for example, Lm.
A is flowing. Assuming that the resistor 67 is IKΩ, when a current of LmA flows through the resistor 67, a voltage of 1 volt is generated across the resistor 67. Now, (1) When Vs - V I N > 1 volt, current flows between the emitter and collector of transistor 62, that is, line A', and the current flows between the emitter and collector of transistor 64, that is, line B, which is zero. (CUFF')
becomes.

At this time, the voltage of Vout (output) increases.

(2) When 0<V s -V I N< 1 volt, both the A' and B' lines become conductive, and the sum of the current flowing through the A' line and the current flowing through the B' line is Lm
It becomes A. At this time, the voltage of V out falls.

(3) When V s −V I N<0, the A' line is turned off and the current becomes zero, and a current of LmA flows through the B' line.

Since a large number of actuated switch circuits that perform the operations (1), (2), and (3) above are connected in parallel, the input analog voltage Vi shown in Fig. 6 is the remainder output for the two-pass alternating box shown in Fig. 7. 68. Non-linear portion 70 of this remainder output 68
At ゜72.74, an inverted V-shaped voltage signal 84 is generated by the compensation circuit.
If we add V-shaped voltage 88 from the compensation circuit to the non-linear portions 76 and 78.

Non-linear parts 70, 72, 74 of the waveform of the remainder output 68,
76.78 is improved. The compensation circuit includes a ninth part 80 of the constant current circuit 68 in FIG. 8 instead of the constant current circuit 68.
Connect as shown. In FIG. 9, the VIN input signal of the remainder output conversion circuit 58 is supplied to the base of the transistor 30 via a level converter 82. With the above configuration, the inverted V-shaped voltage 84 caused by the NPN transistor type compensation circuit a is left over and V o u of the output conversion circuit 58
is added to the voltage and the remainder output 68 portion 70,72°7
The non-linear portion of No. 4 is improved. A in Figure 9.

B and C correspond to A, B and C in FIG. NPN
The same number of PN transistor compensation circuits as the differential switch circuits are provided. Note that the compensation circuit may be provided separately from the remainder output conversion circuit 58. Portion 76 of remainder output 68
A circuit for improving the .degree. 78 non-linearity is shown in FIG. The PNP transistor type compensation circuit is constituted by a PNP transistor 6.8, the line 86 of which is connected to the Vout terminal in FIG. The same number of PNP transistor type compensation circuits as the differential type switch circuits are provided. The V-shaped voltage 88 generated by this compensation circuit is applied to the non-linear portion of the portion 76,78 of the remainder output 68, as shown in FIG. 7, and the portion is improved. In FIG. 10, 90 is a constant current circuit, 92 is a level converter, and 94 is a control signal generation circuit composed of a PNP transistor, which corresponds to the control signal generation circuit in FIG.

〔effect〕

As described above, the present invention enables a pair of transistors to be connected symmetrically, and by inputting mutually symmetrical input voltages whose levels change in two steps to the bases of the pair of transistors, the waveform of the pair of input voltages is The collector current changes in a 7-shape at the intersection of the diodes.

This has the effect of being able to compensate for non-linear parts such as amplifiers and switching circuits using transistors without negative feedback of the output.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram, Figure 2 is a waveform diagram, Figure 3 is a circuit diagram, Figure 4 is a waveform diagram, Figure 5 is a circuit diagram, Figure 6 is a waveform diagram, Figure 7 is a waveform diagram.
The figure is a waveform diagram, Figure 8 is a circuit diagram, Figure 9 is a circuit diagram, and Figure 10 is a circuit diagram.
The figure is a circuit diagram. FIG. 11 is an explanatory circuit diagram, and FIG. 12 is an explanatory diagram. 2.4...Transistor, 6,8...Transistor, 10.12...Current, 14゜16.18.20...Input terminal, 22.24...
...V-shaped part, 26.28...line. 30.32...NPN transistor, 34...
Constant current circuit, 36.38...Collector power supply,
40.42... line, 44.46... line
Transistor, 48.50...terminal. 52...Nonlinear compensation circuit, 54. ．． 56...part, 58...remainder output conversion circuit, 60...pass switch circuit section, 62.64...transistor,
66...Division resistor, 68...Remainder output,
70, 72, 74, 76.78... non-linear part,
80... part, 82... level converter,
84...line. 86... Line Figure 1 Figure 2 Figure 1 (b) Figure 3 Figure 4 Figure 5 Figure 8 Figure 9 Figure 12 (0) (b) March 1985 tq - Day 1988 Patent Application No. 160280 2, Title of the invention: Non-linear output compensation circuit 3, Relationship with the amended person's case Patent applicant address: Hiromu Nakamura, 4-17-18 Omori Kita, Ota-ku, Tokyo Name: Hiromu Nakamura Address: 150 6-19- Jingumae, Shibuya-ku, Tokyo
15 (1) Drawing 6, details of amendment (1) Figure 8 is corrected as shown in the attached sheet.

Claims (1)

[Claims] The collectors and emitters of the pair of transistors 2 and 4 are connected to each other so that the pair of transistors 2 and 4 are symmetrical, and the transistors 2 and
A pair of symmetrical voltage signals whose levels change in two steps are applied to the base of 4, and when the voltage signals cross,
A non-linear output compensation circuit characterized in that the collector currents of the transistors 2 and 4 change in a V-shape.