JPS5862908A - Voltage current converting circuit - Google Patents

Abstract

PURPOSE:To make an output current proportional to an input voltage correctly, by connecting a series circuit consisting of a transistor (TR) and a resistor between an output terminal and a common terminal, in a current mirror circuit. CONSTITUTION:In a current mirror circuit M, a TRQ1 and a TRQ1' connecting its base to the collector are connected in series between an input terminal A and a common terminal C. Further, a TRQ2 and a TRQ2' connecting its base to the collector are connected in series between an output terminal B and the common terminal C. Moreover, a series circuit M consisting of a TRQ3 and a resistor R3 is connected between the output terminal B and the common terminal C, and the base of the TRQ3 is connected to the input terminal A and controlled with a part of a current Ii flowing to the input terminal A and the common terminal C. Through the connection of the circuit H, the relation of an output current I0 to an input voltage has no offset voltage corresponding to the sum of voltage between the base and emitter of the TRs Q1 and Q2, resulting that the output current can be made correctly proportional to the input voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a voltage-current conversion circuit that converts an input voltage into an output current corresponding to the input voltage.

The new voltage-current conversion circuit has a current mirror circuit M having an input terminal A, an output terminal B, and a common terminal C common to the input terminal A and the output terminal B, as shown in FIG. Then, the input voltage source 8 is connected to II through the input resistor RO between the input terminal M and the common terminal C of the current mirror circuit M.
! Furthermore, a configuration has been proposed in which an IT source E is connected through a load between the output terminal B and the common terminal C of the current mirror circuit M'.

In this case, such a voltage-current conversion circuit has an input resistance 3 based on an input voltage obtained from its input voltage source 8 (this is assumed to be V).
0. and the input terminal M and common terminal C of the current mirror circuit M.
A current flows through the current mirror circuit M (I
, ) flows, and as a result, load L1 is transferred from power source B
In this mechanism, a current flows as an output current (this is designated as Io) in the current mirror circuit M through the output terminal B and the common terminal C of the current mirror circuit M, and the input voltage V
is converted into an output current I0 according to the current,
A current mirror circuit M having the following configuration has been proposed. Namely, as shown in FIG.
The bipolar transistor Q1 of NPNIi connects its collector to the collector, and the bipolar transistor of NPNfi connects its base to the collector. An NPN-type bipolar transistor Q2 is connected between the output terminal B and the common terminal C in a manner that Q 2 / is connected to the common terminal C, and the transistor Q
The base of transistor Q2 is connected to the emitter of transistor Q2, and the base of transistor Q2 is connected to input terminal A, so that the current passing through both inputs and the common terminal C is fLIi. - the transistors Q1 and Q2 are controlled by flowing through the emitters so that a current I, 61. ) flows through the transistor Q1' (which acts as a diode since its base and collector are connected together) and through the transistor Q1 through its collector-emitter, and the output current I0 flows through the transistor Q2 through its collector-emitter. flows through and transistor Q2'(
It has been proposed to flow through a diode (its base and collector are connected together so that it acts as a diode).

In addition, as a voltage-current conversion circuit, in the configuration described above in FIG. 1 as shown in FIG. A configuration similar to that in FIG. 3 has also been proposed, except that it is connected to the common end C of the power source E, and is connected at the opposite end to the common end C of the power source E. ing.

By the way, such a voltage-current conversion circuit has a mechanism similar to the voltage-current conversion circuit described above in FIG. However, a method having the following configuration has been proposed as the Karen)-Niu--route M.

That is, as shown in Figure 184, between the input terminal A and the common terminal C,
In the 211th case, the transistor Q1 of Hajime Oka is connected in such a manner that its collector and emitter are directly connected to the input terminal M and the common terminal C, respectively, and the transistor Q1 is connected between the output terminal B and the common terminal C. In 11I2, the same transistor Q as in Fig.
2 is connected in such a manner that its collector and emitter are directly connected to the output terminal B and the common terminal C, respectively, while the base and collector are respectively connected to the input terminal and the power supply terminal, and the emitter is connected to the transistor It has an NPN@ bipolar transistor Q6 connected to the bases of Q1 and Ql, so that part of the electric current passing through the input terminal A and the common terminal C is
Transistors Q1 and Ql are controlled by flowing through the base-emitters of transistors Q6 and Ql; and the base-emitters of transistors Q6 and Ql, respectively, so that currents I and Io flow through the collectors and emitters of transistors Q1 and Ql, respectively. It has been proposed that the structure is structured so that it flows through the air.

As shown in FIG. 5, as a current mirror circuit M, in the configuration described above in FIG. A configuration similar to that shown in FIG. 4 has also been proposed, except for the insertion.

Furthermore, as a current mirror circuit M, as shown in FIG.
In the configuration described above in FIG.
l, are NPN type bipolar transistors Q7 and Q
A configuration similar to that shown in FIG. 5 has also been proposed, except that B is replaced with a configuration in which B is connected in a Darlington type.

However, in the voltage-current conversion circuit described above in FIG.
In the voltage-current conversion circuit shown in the figure above, if the current mirror circuit M having the structure shown in Figs. 4, 5, and 6 is used, the input voltage 4 and The output current I0 has the following relationship.

However, ■ in Equation 11 means that when the current mirror circuit M has the configuration shown in Figure 2, the transistors Q1 and Q
The base-emitter voltage of l is respectively 1. ．． and VIm
2, it has the value of their sum, so V□,
m V□2==■□ and -ruki, V, ≧2■□ 1
Has directness. Also, the mirror circuit M is as shown in Figures 4 and 5.
If it has the configuration shown in the figure, ■11111 ” ■1112
” vBN tL', also) 9y dix/Q6 base-
When the emitter voltage ■□6 is VIm, % v5
It has a value of ``' 2■BE.

Furthermore, when the current mirror circuit M has the # configuration shown in FIG.
2 and vBI, it has a value of V, = S V□. In addition, when the current mirror circuit M has the configurations shown in FIGS. 2 and 4, t has a value of r==ro when the resistance ro of the input resistor RO is set, and the current mirror circuit M has a value of r==ro. When having the configuration shown in Fig. 6 and Fig. 6,
When the values of the resistors R1 and R2 are r1 and r2, respectively, and r, 3r2:=r', the value is f m g'.

Therefore, when the current mirror circuit M having the configuration described above in FIG. 2 is used in the voltage-current conversion circuit of FIG. 1, and in the voltage-current conversion circuit of FIG. When the current mirror circuit M having the configuration described above in FIGS. 4, 5, and 6 is used, the relationship between the output current °Io and the input voltage ■ is as shown in FIG. Looking at the output current I0 characteristic, as shown by the dotted line, there is an offset of 1 voltage due to the voltage vs, with an error of -5·N.
Therefore, it is not possible to obtain a highly accurate output current I0 that is correctly proportional to the input direct voltage (2).

Therefore, the invention is intended to propose a novel voltage-current conversion circuit free from the above-mentioned drawbacks, which will become clear from the detailed description below.

An example of the pressure current conversion circuit according to the present invention has the configuration described above in FIG. 1, but instead of the configuration described above in FIG. ,
In the configuration described above in FIG. 2, the output jiiiB
and a common terminal C, there is connected a series circuit 11 in which the emitter of the transistor Q5 of the NPN II bipolar transistor Q5 and the resistor R5 is connected to one end of the resistor R5, the collector of the transistor Q5 is connected to the output terminal B, and the resistor B-3
The transistor Q5 is connected with its other end to the common terminal C, and its base is connected to the input terminal M, so that a current I is connected.

The configuration used is the same as that in Figure 2 e4, except that it is controlled by a part of the .

Another example of the voltage-current circuit according to the present invention has the configuration described above in FIG. 2, and as the current mirror circuit M,
Instead of the configuration described above in FIG. 4, as shown in FIG.
In the configuration of FIG. 14, a series circuit H of a transistor Q5 and a resistor B5 similar to those described above in FIG. 8 is connected at an output end B and a common end C-6° as in the case of FIG. 1 as in FIG. 4, except that the transistor Q5 is connected with its base to the input terminal and is controlled by a portion of the current Ii. The configuration is used.

Furthermore, another example of the voltage-current conversion circuit according to the present invention is as shown in FIG. 10, in which, in the configuration shown in FIG. 5, the current mirror circuit M is replaced with the configuration shown in FIG. , in the configuration shown in Fig. 5, the output end B and the transistor J
A series circuit H1 consisting of a PNPfi bipolar transistor Q4 and a resistor R4 similar to the series circuit H1 described above in the 8th WJ is connected between Q1 and the connection midpoint of the resistor R1, with the transistor Q4 serving as the output @B side. In addition, a series circuit n2 of a transistor Q5 and a resistor R5, which is similar to the series circuit H1, is connected between the output terminal B and the midpoint of the connection between the transistor Q2 and the resistor a2, with the transistor JQ5 on the output terminal B side. , and the case of Figure 5 except that transistors Q4 and Q5 are connected to both inputs through their mousses and are made to be controlled by a portion of the current tl. or as described above in FIG. 6.

Instead of the configuration, as shown in FIG. 11, in the configuration of FIG. 6, the series circuits H1 and H2 similar to the case of FIG.
The transistor Q4 is connected in the same way as in Figure 0.
and Q5, with their bases followed by the base of transistor Q8, so as to be controlled by a portion of the current Ii. is what is used.

/ Examples of the voltage and power conversion circuit according to the present invention have been clarified above, but except for the matters mentioned above, they are the same as the first example.
8 and 9, respectively, as the current mirror circuit M in the configuration of FIG. 1 and M2B5.
When using the configuration shown in the figure, the transistor Q
If the base-emitter voltage of transistor 6 is VBBS ``''B□, the collector current I2 of 2 is equal to the current when V is 2■□ in equation 11, Also, the collector current l of transistor Q3
, the value of resistor R3 is r5, which is VBI/r
It is represented by H, and therefore. In addition, in the configuration of the sixth hook, as the current mirror circuit M, the first (II
Since the eleventh circuits R1 and R2 have a configuration in which the series circuit H in the configuration of FIG. 9 is divided into two,
Let the values of resistors R4 and R5 be r4 and r5, respectively, and rl :r2-1 :17N, f, +17. ．． =
', 7γ% h (5=f*%), the relationship expressed by equation (2) above can be obtained.

Therefore, according to the invention, the output current I for the input voltage V
0 is the output voltage ft, lo when the input voltage is V in Figure 7.
Look at the characteristics, it's true! 11! As you can see, it is obtained as if there is no offset voltage due to voltage v8,
This has the great advantage of being able to obtain an output current with a high N degree that is correctly proportional to the input voltage V without causing the tI4 difference as in the conventional case.

In the description of improvements, although we have shown examples of false examples of the present invention, there are many variations that can be made without departing from the spirit of the present invention! changes could be made. ′

[Brief explanation of the drawing]

Figure 1 is a connection diagram showing an example of a 11L*voltage converter circuit. Figure 2 is a connection diagram showing a conventional current < error circuit M that can be used by one company. 4, 5, and m6 can be used for this purpose. A connection diagram showing a conventional current mirror circuit M, Figure 1g7 is a characteristic diagram of input voltage V vs. output current 10, Figures 8, 9, tlI, 10 and 11-
is a connection showing an embodiment of the circuit M used in the present invention. Source: Nippon Telegraph and Telephone Company Figure 1 @ 2TA Figure 23 r Sakaki I Figure 4; 2. Title of the invention: Voltage-current converter circuit 3. Patent applicant related to the amendment case: 4. Attorney (1): In the specification, page #! 6, line 4, ``external power supply connection terminal.'' Correct it to "Outside, power connection end." (2) On page 6, line 6, "Connection 31" should be corrected to "M2 diagram." (3) Therefore, in the 8th Kan, line 14, “the relationship of the following formula” is changed to “
If N is the amplification factor, the following equation is corrected. There is a certain thing. (5) Please replace "Voltage■□," on page 9, line 10 with "
Correct the voltage to vIll 7J. (6) Please, page 9, line 14, “resistance yeJ”
, the value of ” and the turn to correct:. (...sg2 term on the right side of the equation)" is corrected. (8) Therefore, on page 11, line 2, the words "with 几5" are corrected to "with 3." (9) Please replace the phrase “Figure 2” on page 11, lines 11-12 with “
Please correct the phrase ``Similar PNP type'' on page 12, line 9, to ``Figure 5.''
It is corrected as "NPN type". Qll, @page 14, lines 7-18 “Transistor Q2
This is... ” is corrected as follows. "The collector tILft,12 of the transistor Q2 is
In the formula mentioned above, it is equal to the current when v8 is 2v□, and the collector voltage of transistor Q3 [
1s is between the base and emitter of the transistor QS.
If the pressure is VBBS ” ■111!, then the resistance R,
(7) If 1 key is r3, then it is expressed as vBI!i/r, and therefore the output, IL1, is (12 + 1.). Therefore, if r is set as -1 in advance, then N." a2 Therefore, replace the line 8 of page 15 with "Kukata voltage at V" with "
Correct it to ``input voltage v vs.''. 0.Page 15, line 9, ``Jitonzu'' is replaced with ``Jitsu-douzu.''
I am corrected. that's all

Claims (1)

[Claims] 1. An input end, an output end, and a common end common to the input end and the output end, and between the input end and the common end, the input end and a first transistor controlled by the % flow through the common terminal, connected between the output terminal and the common terminal, a second transistor controlled by the % flow through the input terminal and the common terminal. is connected to the current mirror circuit, and an input terminal source is connected between the input terminal and the common terminal of the current mirror @ path through an input resistor, and the current mirror &gl
The voltage 111tIt conversion circuit number is connected to the power supply with the above output terminal of the sweetfish and the above negative # connected to the above output terminal.In this case, the above input terminal is traced to the run between the above output terminal and the above common terminal.
A voltage-current conversion path characterized by a connection between a sixth transistor controlled by ILtIt and a third resistor. 2. has an input end, an output end, and a common end common to the input end and the output end, and is controlled by a current passing through the input end and the common end between the input end and the common end. A series circuit of a first transistor and a first resistor is connected with the first resistor as the common end side,
A series circuit of a second transistor and a second resistor, which is controlled by the current flowing through the input terminal and the common terminal, is connected between the output terminal and the common terminal, with the second resistor on the common terminal side. an input voltage source is connected through an input resistor between the input end and the common end of the current mirror circuit; and an input voltage source is connected between the output end and the common end of the current mirror circuit. In a voltage-current conversion circuit in which a power supply is connected through a load, a current passing through the input terminal is applied between the output terminal and the midpoint of the connection between the first transistor and the first resistor. A series circuit of a fourth transistor to be controlled and a fourth resistor is connected, and a current passing through the input terminal is connected between the output terminal and a connection midpoint of the second transistor and the second resistor. 1. A voltage-current conversion circuit comprising a series circuit of a fifth transistor controlled by a fifth resistor and a fifth resistor connected together.