Controller for electronically controlling a resistor

Abstract

The controller for the electronically controlled resistor comprises a controllable current generator outputting a current; an amplifier receiving an input voltage proportional to the output current and outputting an amplified input voltage to a first input of a summer; a voltage divider connected between a high potential end and a low potential end of the electronically controlled resistor; a buffer stage receiving an output of an external sensing resistor and outputting a buffer voltage to the controllable current generator to control the output current, and outputting the buffer voltage to a second input of the summer, wherein the summer outputs a sum voltage; and an operational amplifier receiving the divided voltage and the sum voltage and outputting a control voltage to an external active element, wherein the active element and the sensing resistor are connected in series between the high potential end and the low potential end of the electronically controlled resistor.

Description

Technical Field

[0001] This invention relates to the fields of electrical engineering and electronics, particularly measuring equipment, power electronics, radio engineering and communications, and consumer electronics. More specifically, this invention relates to controlling changes in the resistance of a circuit section using electronic means. Background Technology

[0002] In many electronic applications, the ability to electronically alter the resistance of circuit components over a wide range is of paramount importance. Solving this problem will open new possibilities for creating automated electrical, radio, and other devices for various applications, including the Internet of Things (IoT).

[0003] The controller of an electronically controlled resistor (ECR) generates a control voltage that changes the resistance of the active element in the ECR over a wide range, depending on the magnitude of the input action.

[0004] The electronically controlled resistor typically includes an active element, a measuring (sensing) resistor, and a controller for the electronically controlled resistor. Input actions involve changing the resistance value of a variable control resistor, such as a mechanical potentiometer, photoresistor, thermistor, digital potentiometer, etc., which are not part of the electronically controlled resistor.

[0005] Many solutions are known in this art. For example, patents RU2666786, RU2661348, RU2658681, US10447167, I670920(TW), I674742(TW), and KR10-2054359 disclose a controller for an electronically controlled active element of a resistor, which has the following features (see relevant publications). Figure 1 (This shows a conventional controller):

[0006] - The first terminal of the controller is used to connect the circuit to the control voltage source;

[0007] - The second terminal of the controller is used to connect the circuit to the low-potential terminal of the electronically controlled resistor;

[0008] - The controller's third terminal serves as its output, used to connect the circuit to the control input of the active element, which is part of the electronic control resistor.

[0009] Traditional controllers also include operational amplifiers, reference resistors, feedback resistors, and constant voltage sources. The non-inverting input of the operational amplifier is connected to the first terminal of the reference resistor, and the second terminal of the reference resistor is connected to the first terminal of the controller.

[0010] The non-inverting input of the operational amplifier is also connected to the first terminal of the feedback resistor, the second terminal of the feedback resistor is connected to the output of the operational amplifier, and the output of the operational amplifier is connected to the third terminal of the controller; and

[0011] The inverting input of the operational amplifier is connected to the positive terminal of the constant voltage source.

[0012] This traditional solution has the following drawbacks:

[0013] - The circuit's resistor control accuracy is insufficient, especially under unstable factors such as ambient temperature;

[0014] - It is not possible to use variable resistors (photoresistors, thermistors, digital potentiometers, etc.) to control the resistance of a circuit section.

[0015] Another conventional solution is mentioned in publication SU1807554 dated April 7, 1993. The conventional circuit section of the resistor controller includes (see relevant publications)... Figure 2 , 3 ):

[0016] - The first terminal of the controller is used to connect the circuit to the high-potential terminal of the electronically controlled resistor;

[0017] - The second terminal of the controller serves as its output terminal, used to connect the circuit to the first terminal of the sensing resistor, which is part of the electronic control resistor.

[0018] - The third terminal of the controller is used to connect the circuit to the control action source as a variable analog voltage;

[0019] - The fourth terminal of the controller is used to connect the circuit to the low-potential terminal of the electronically controlled resistor.

[0020] Traditional solutions also include:

[0021] - Control action conversion circuit;

[0022] -Operational amplifier;

[0023] - A feedback resistor;

[0024] - A limiting resistor;

[0025] - A constant voltage source;

[0026] In this configuration, the non-inverting input terminal of the operational amplifier is connected to the first terminal of the limiting resistor, while the second terminal of the limiting resistor is connected to the fourth terminal of the controller.

[0027] The inverting input of the operational amplifier is connected to the output of the control action conversion circuit and the first terminal of the feedback resistor; the second terminal of the feedback resistor is connected to the output of the operational amplifier and the second terminal of the controller; and

[0028] The first input terminal of the control action conversion circuit is connected to the first terminal of the controller, the second input terminal is connected to the third terminal of the controller, and the third input terminal is connected to the positive terminal of the constant voltage source.

[0029] The output of the operational amplifier is connected to the second terminal of the controller.

[0030] This traditional solution has the following drawbacks:

[0031] - Lack of control over the active part of the electronically controlled resistor;

[0032] - It cannot be controlled using variable resistors (photoresistors, thermistors, digital potentiometers, etc.);

[0033] - There is an inverse relationship between the resistance of the electronically controlled resistor and the control effect represented by the changing analog voltage; and

[0034] - It is impossible to obtain electronically controlled resistors with sufficiently low resistance, which is often the practical requirement.

[0035] The final drawback is that in traditional solutions, the current flowing through the sensing resistor passes through the series-connected limiting resistor and reference resistor, closing on a common conductor. Therefore, there is a practical relationship between the resistance of the electronically controlled resistor and the resistances of the limiting and reference resistors. This relationship can only be ignored when the resistance of the sensing resistor is many times higher than the combined resistance of the limiting and reference resistors, leading to the aforementioned drawback.

[0036] U.S. Patent No. 4,833,472, issued on May 23, 1989, discloses another conventional circuit part resistor controller.

[0037] This traditional solution includes (see relevant publications) Figure 1 ):

[0038] - The first terminal of the controller is used to connect the circuit to the high-potential terminal of the electronically controlled resistor;

[0039] - The second terminal of the controller is used to connect the circuit to the first terminal of the sensing resistor, which is part of the electronically controlled resistor;

[0040] - The controller's third terminal (a set of terminals) is used to connect the circuitry to the control digital code source;

[0041] - The fourth terminal of the controller is used to connect the circuit to the low-potential terminal of the electronically controlled resistor.

[0042] - The fifth terminal of the controller serves as its output terminal, used to connect the circuit to the control input terminal of the active element, which is part of the electronic control resistor.

[0043] Traditional controllers also include an operational amplifier, a multiplier, and a digital-to-analog converter.

[0044] The non-inverting input of the operational amplifier is connected to the first terminal of the controller.

[0045] The inverting input of the operational amplifier is connected to the output of the digital-to-analog converter, while its input is connected to the output of the multiplier. The output of the operational amplifier is connected to the fifth terminal of the controller.

[0046] The third terminal (a set of terminals) of the controller is connected to the first input terminal (a set of input terminals) of the multiplier, and the second input terminal of the multiplier is connected to the second terminal of the controller.

[0047] The main drawback of this traditional solution is that it cannot be controlled using variable resistors (photoresistors, thermistors, digital potentiometers, etc.).

[0048] Another conventional controller for the circuit part resistor was also disclosed in JPS 5111404 document dated October 7, 1976.

[0049] Traditional solutions include (see relevant publications) Figure 1 ):

[0050] - The first terminal of the controller is used to connect the circuit to the high-potential terminal of the electronically controlled resistor;

[0051] - The second terminal of the controller is used to connect the circuit to the first terminal of the sensing resistor, which is part of the electronically controlled resistor;

[0052] - The controller's third terminal (a set of terminals) is used to connect the circuitry to the control digital code source;

[0053] - The fourth terminal of the controller is used to connect the circuit to the second terminal of the control digital code source;

[0054] - The fifth terminal of the controller is a low-potential terminal used to connect the circuit and the electronic control resistor;

[0055] - The sixth terminal of the controller serves as its output terminal, used to connect the circuit to the control terminal of the active element, which is part of the electronic control resistor.

[0056] A traditional controller also includes an output operational amplifier and an intermediate operational amplifier, a repeater, an inverter, a bias resistor, a reference resistor, and a digital-to-analog converter.

[0057] The input terminal of the repeater is connected to the first terminal of the controller, its output terminal is connected to the first terminal of the reference resistor, and the second terminal of the reference resistor is connected to the inverting input terminal of the intermediate operational amplifier.

[0058] The inverting input of the intermediate operational amplifier is also connected to the output of the digital-to-analog converter (DAC) via a bias resistor, while the input of the DAC is connected to the third terminal (a set of terminals) of the controller; and

[0059] The non-inverting input of the intermediate operational amplifier is connected to the fifth terminal of the controller, and its output is connected to the non-inverting input of the output operational amplifier via an inverter. The inverting input of the output operational amplifier is connected to the second terminal of the controller.

[0060] The main drawback of traditional solutions is that they cannot be controlled using variable resistors (photoresistors, thermistors, digital potentiometers, etc.).

[0061] However, DE3239309, published on April 26, 1984, disclosed another conventional circuit-part resistor controller.

[0062] Traditional controllers for circuit section resistors include (see relevant publications) Figure 2 ):

[0063] - The first terminal of the controller is used to connect the circuit to the high-potential terminal of the electronically controlled resistor;

[0064] - The second terminal of the controller is used to connect the circuit to the first input terminal of the current-to-voltage converter, which is part of an electronically controlled resistor;

[0065] - The controller's third terminal is used to connect the circuit to a control voltage source designed as a digital-to-analog converter;

[0066] - The fourth terminal of the controller is used to connect the circuit to the second terminal of the control voltage source;

[0067] The fifth terminal of the controller is used to connect the circuit to the low-potential terminal of the electronic control resistor;

[0068] - The sixth terminal of the controller serves as its output terminal, used to connect the circuit to the control input terminal of the active element, which is part of the electronic control resistor.

[0069] Traditional controllers also include an operational amplifier and an analog voltage divider.

[0070] The inverting input of the operational amplifier is connected to the second terminal of the controller, while the non-inverting input is connected to the output of the analog voltage divider.

[0071] The main drawback of traditional solutions is that they cannot be controlled using variable resistors (photoresistors, thermistors, digital potentiometers, etc.).

[0072] The closest analogue (prototype) to this invention, namely EP3182243A1 dated June 21, 2017, discloses a conventional circuit section resistor controller, comprising (see relevant publications) Figure 1 With respect to this application Figure 1 same):

[0073] - The first terminal of the controller is used to connect the circuit to the high-potential terminal of the electronically controlled resistor;

[0074] - The second terminal of the controller is used to connect the circuit to the first terminal of the sensing resistor, which is part of the electronically controlled resistor;

[0075] - The third terminal of the controller is used to connect the circuit to the first terminal of the control resistor;

[0076] - The fourth terminal of the controller is used to connect the circuit to the second terminal of the variable control resistor;

[0077] - The fifth terminal of the controller is a low-potential terminal used to connect the circuit and the electronic control resistor;

[0078] - The sixth terminal of the controller serves as its output terminal, used to connect the circuit to the control input terminal of the active element, which is part of the electronic control resistor.

[0079] Traditional controllers also include: operational amplifiers, reference resistors, constant voltage sources, and uncontrollable current generators.

[0080] The non-inverting input of the operational amplifier is connected to the fourth terminal of the controller and the first terminal of the reference resistor, and the second terminal of the reference resistor is connected to the fifth terminal of the controller.

[0081] The inverting input of the operational amplifier is connected to the second terminal of the controller.

[0082] The output of the operational amplifier is connected to the sixth terminal of the controller.

[0083] The first and third terminals of the controller are interconnected and further connected to the output terminal of the uncontrollable current generator, while the input terminal of the generator is connected to the positive terminal of the constant voltage source.

[0084] The main drawback of this traditional solution is that digital potentiometers with grounded terminals, such as ISL90728WIE627Z-TK, TPL0401A-10DCKR, and MCP4018T-103E / LT, cannot be used as control resistors.

[0085] Digitally controlled potentiometers have neither active components nor sensing resistors, and therefore are not closely related to existing technology.

[0086] Therefore, there is a need in the art for an electronically controlled resistor controller that can precisely set the required resistance while making the resistance of the electronically controlled resistor linearly (proportionally) to the resistance of various variable control resistors (such as photoresistors, thermistors, various digital potentiometers, including digital potentiometers with grounding terminals). Summary of the Invention

[0087] The purpose of this invention is to overcome the drawbacks of traditional solutions and to manufacture a controller for electronically controlled resistors, thereby enabling precise setting of the resistance of a given circuit section (even relatively small resistances) over a wide range. At the same time, various variable control resistors, including any kind of digital potentiometer, can be used to set the required resistance, while ensuring that the resistance of the thyristor is linearly (proportional) to the resistance of the variable control resistor.

[0088] The technical achievement of this invention includes using various digital potentiometers as variable control resistors for electronically controlled resistors, thereby expanding the range of technical means to realize them as controllers for electronically controlled resistors.

[0089] In the specification and subsequent claims, when one element is described as being "coupled" to another element, the element may be "directly coupled" to the other element or "electrically coupled" to the other element through a third element.

[0090] Furthermore, unless explicitly stated otherwise, the word "including" and its variations such as "comprising" or "consisting of" should be understood as including the stated elements without excluding any other elements.

[0091] In one aspect, an electronic controller for electronically controlled resistors is provided (e.g., see...). Figure 2The electronic controller for the electronically controlled resistor may include a current generator that outputs a current; an amplifier that receives an input voltage proportional to the output current and outputs the amplified input voltage to a first input terminal of an adder; a voltage divider that includes a bias resistor and a reference resistor connected in series between the high and low potential terminals of the electronically controlled resistor; and a buffer stage that receives the output of the sensing resistor of the electronically controlled resistor and outputs a buffered voltage to a second input terminal of the current generator and the adder, wherein the adder outputs a summed voltage. Furthermore, the electronic controller for the electronically controlled resistor may include an operational amplifier that receives the divided voltage at its first input terminal, receives the summed voltage at its second input terminal, and outputs a control voltage to the active element of the electronically controlled resistor.

[0092] Optionally, one side of the variable control resistor is connected to the low-potential terminal of the electronically controlled resistor, and the other side is connected to the current output terminal, wherein the input voltage is the voltage across the variable control resistor. Optionally, the active element is a MOSFET transistor. Optionally, the current generator is a controllable current generator. Optionally, the active element and the sensing resistor of the electronically controlled resistor are connected in series.

[0093] Optionally, a controllable current generator (e.g., see...) Figure 3 The system includes: a second operational amplifier that receives the output voltage of a buffer stage and a voltage proportional to the resistance of a first resistor of a controllable current generator; a first transistor that receives the output voltage of the second operational amplifier and outputs a main current to the first resistor; a second resistor connected in series between the power supply voltage and the first transistor, with the common node of the second resistor and the first transistor connected to the first input terminal of a third operational amplifier; a third resistor connected in series between the power supply voltage and the second transistor, with the common node of the third resistor and the second transistor connected to the second input terminal of the third operational amplifier; and a second transistor that receives the output voltage of the third operational amplifier and outputs a controllable output current from the controllable current generator.

[0094] On the other hand, the electronically controlled resistor including the aforementioned controller may include a current generator capable of outputting an output current; an amplifier that receives an input voltage proportional to the output current and the value of the variable control resistor, and outputs the amplified input voltage to the first input terminal of an adder; a voltage divider including a bias resistor and a reference resistor connected in series between the high-potential and low-potential terminals of the electronically controlled resistor; an active element and a sensing resistor connected in series at the high-potential terminal of the electronically controlled resistor. Between the high and low potential terminals; a buffer stage that receives the output of the sensing resistor of the electronically controlled resistor and outputs a voltage; an active element and a sensing resistor connected in series between the high and low potential terminals of the electronically controlled resistor; a buffer stage that receives the output of the sensing resistor of the electronically controlled resistor and outputs a buffered voltage to the second input of a current generator and an adder, wherein the adder outputs a summed voltage; and an operational amplifier that receives a divided voltage at its first input, receives a summed voltage at its second input, and outputs a control voltage to the active element of the electronically controlled resistor.

[0095] Optionally, one side of the variable control resistor is connected to the low-potential terminal of the electronically controlled resistor, and the other side is connected to the current output terminal, wherein the input voltage is the voltage across the variable control resistor. Optionally, the active element of the electronically controlled resistor is a MOSFET transistor. Optionally, the current generator is a controllable current generator.

[0096] Optionally, the controllable current generator includes: a second operational amplifier that receives the output voltage of a buffer stage and a voltage proportional to the resistance of a first resistor of the controllable current generator; a first transistor that receives the output voltage of the second operational amplifier and outputs a main current to the first resistor; a second resistor connected in series between the power supply voltage and the first transistor, with the common node of the second resistor and the first transistor connected to the first input terminal of a third operational amplifier; and a second transistor connected in series between the power supply voltage and the second transistor, with the common node of the third resistor and the second transistor connected to the second input terminal of the third operational amplifier; a third resistor connected in series between the power supply voltage and the second transistor, with the common node of the third resistor and the second transistor connected to the second input terminal of the third operational amplifier; the second transistor receives the output voltage of the third operational amplifier and outputs a controllable output current of the controllable current generator.

[0097] Other features and advantages of the invention will be set forth in the description which follows, and some features and advantages will become apparent from the description or may be learned by practice of the invention. The advantages of the invention will be realized and achieved by means of the structures particularly pointed out in the written description, claims, and drawings.

[0098] It should be understood that the above general description and the following detailed description are exemplary and explanatory, and are intended to provide further explanation of the claimed invention. Attached Figure Description

[0099] The accompanying drawings illustrate embodiments of the present invention, and together with the description, explain the principles of the invention.

[0100] In the drawings

[0101] Figure 1 A conventional controller (existing technology) is shown.

[0102] Figure 2 An exemplary embodiment of a device for controlling an active element of an electronically controlled resistor is shown, the device being controlled by a variable control resistor, such as a mechanical potentiometer, a photoresistor, a thermistor, a digital potentiometer, etc.

[0103] Figure 3 An exemplary implementation of a controllable current generator that can be used in a controller is shown.

[0104] Figure 4 The experimental results of the device prototype were presented. Detailed Implementation

[0105] Preferred embodiments of the invention will now be described in detail, with examples of these embodiments shown in the accompanying drawings.

[0106] To achieve the above-mentioned technological achievements, the proposed equipment includes (see...) Figure 2 , Figure 2 An exemplary embodiment of a device (controller 220) for controlling an electronically controlled resistor 222 is shown:

[0107] - The first terminal 1 of the controller 220 is used to connect the controller 220 to the first terminal of the variable control resistor Rc;

[0108] - The second terminal 2 of the controller 220, which is used to connect the controller 220 to the first terminal of the sensing resistor, is part of the electronically controlled resistor 222;

[0109] - The third terminal 3 of the controller 220 is used to connect the controller 220 to the control terminal of the active element 224, which is part of the electronic control resistor 222.

[0110] - The fourth terminal 4 of the controller 220 is used to connect the controller 220 to the second terminal of the variable control resistor Rc.

[0111] - The fifth terminal 5 of the controller 220 is used to connect the controller 220 to the low-potential terminal 12 of the electronic control resistor 222;

[0112] - The sixth terminal 6 of the controller 220 is used to connect the controller 220 to the high-potential terminal 10 of the electronic control resistor 222.

[0113] -Operational amplifier 208;

[0114] - A reference resistor R ref ;as well as

[0115] -Constant voltage source (such as battery) 214

[0116] The non-inverting input of operational amplifier 208 is connected to the reference resistor R. ref The first terminal, the reference resistor R ref The second terminal is connected to the fifth terminal 5 of the controller 220, and the output terminal of the operational amplifier 208 is connected to the third terminal 3 of the controller 220.

[0117] The controller 220 is also equipped with:

[0118] - Bias resistor R bias ;

[0119] -Amplifier 204;

[0120] - Adder 206;

[0121] -Buffer level 210; and

[0122] - Controllable current generator 212

[0123] in,

[0124] - The first terminal of the bias resistor is connected to the sixth terminal 6 of the controller 220, and the second terminal of the bias resistor is connected to the non-inverting input terminal of the operational amplifier 208;

[0125] - The input terminal of amplifier 204 is connected to the first terminal 1 of the device, the output terminal of amplifier 204 is connected to the first input terminal of adder 206, and the output terminal of adder 206 is connected to the inverting input terminal of operational amplifier 208;

[0126] - The second terminal 2 of the device is connected to the input terminal of the buffer stage 210, and the output terminal of the buffer stage 210 is connected to the second input terminal of the adder 206 and the control input terminal of the controllable current generator 212;

[0127] - The power input terminal 22 of the controllable current generator 212 is connected to the positive terminal of the DC power supply 214, and the negative terminal of the DC power supply 214 is connected to the low potential terminal of the electronically controlled resistor; and

[0128] - The output terminal 26 of the controllable current generator 212 is connected to the first terminal 1 mentioned above. The purpose of this terminal is to transmit control actions, namely, to change the variable control resistor R. c The resistance value.

[0129] By adding a bias resistor R bias The amplifier 204, adder 206, buffer stage 210, and controllable current generator 212, connected accordingly according to the recommendations of this invention, can generate a constant potential at the non-inverting input of operational amplifier 208 when the voltage U1 on the high-potential terminal 10 of the switching electronic control resistor 222 is switched.

[0130] U1'=U1*R ref / (R ref +R bias ), (1)

[0131] Among them, R bias It is the resistance of the bias resistor, R ref It is the resistance of the reference resistor.

[0132] At the same time, the inverting input of operational amplifier 208 receives a summation signal S consisting of the following summation values:

[0133] The first sum S1 is transmitted from the first terminal 1 of the proposed controller 220 through amplifier 204 to the first input terminal of adder 206 with an amplification factor K'. The first sum is controlled by a variable control resistor R. с The amplified voltage drop indicates that the voltage drop is caused by the current Icg generated by the controllable current generator 212, i.e.

[0134] S1=K'*Icg*R с (2)

[0135] The second sum S2 is transmitted from the second terminal 2 of the proposed controller through the buffer stage 210 to the second input terminal of the adder 206 in a unity transfer ratio. The second sum is determined by the sensing resistor R. sense The voltage U2 indicates that Rsense is part of the electronically controlled resistor 222 controlled by the proposed controller 220.

[0136] The voltage is defined by the following formula:

[0137] U2=I0*R sense (3)

[0138] Where Rsense is the value of the sensing resistor, which should be as small as possible during implementation.

[0139] I0 is the current value flowing through the electronically controlled resistor 222, which is determined by the active element 224, a part of the electronically controlled resistor 222.

[0140] therefore,

[0141] S2=U2=I0*R sense (4)

[0142] The sum signal S at the inverting input of operational amplifier 208 is

[0143] S = S1 + S2 = K' * Icg * R с +I0*R sense (5)

[0144] Now, considering that the current Icg of the controllable current generator 212 depends on the voltage U2 transmitted from the output of the buffer stage 210 to the control input 24 of the controllable current generator, that is...

[0145] Icg=U2*Gcg=I0*R sense *Gcg, (6)

[0146] Where Gcg is the coefficient that controls the conversion of voltage U2 into current, and is equal to the conductivity.

[0147] Therefore, according to formulas (5) and (6),

[0148] S=K'*I0*Rsense*Gcg*Rс+I0*Rsense=I0*Rsense*(1+K'*Rс*Gcg)(7)

[0149] The difference between the output terminals U1' and S of operational amplifier 208 is used as the control signal U. contr (U contr =U1'-S) is transmitted to the third terminal 3 of the controller 220 for connecting the circuit to the control terminal of the active element 224 (the active element 224 is part of the electronically controlled resistor 222), i.e., the output terminal of the proposed controller. This is due to the feedback chain (operational amplifier 208 - active element 224 of the electronically controlled resistor - sensing resistor R) sense The amplification factor in the buffer stage 210, adder 206, and operational amplifier 208 is relatively high, so the relationship U1'≈S is true in terms of actual accuracy.

[0150] Therefore, formulas (1) and (7)

[0151] U1*R ref / (R ref +R bias )=I0*Rsense*(1+K'*R с *Gcg) (8)

[0152] Therefore, it can be seen that electronically controlled resistors (see...) Figure 2The resistance between the high-potential terminal 10 and the low-potential terminal 12 is: R0 = U1 / I0 = R sense *(1+K'*R с *Gcg) / (1+R bias / R ref (9)

[0153] Formula (9) shows that, according to this disclosure, the resistance of the electronically controlled resistor is the same as that of the sensing resistor R. sense The resistance is proportional to the control action, and the control action corresponds to the resistance of the variable control resistor Rc (such as a digital potentiometer).

[0154] Formula (9) also shows that if both of the following relations are true, it is possible to achieve low R. sense Obtaining low and ultra-low R values ​​under the following conditions:

[0155] R c *(K'*Gcg)<<1andR bias ≈R ref (10)

[0156] Similar to traditional solutions, the variable control resistor Rc can be represented by a mechanical potentiometer, a photoresistor, or a thermistor.

[0157] The advantage of the proposed circuit is that it can use any kind of digital potentiometer, including digital potentiometers with ground terminals, as the control resistor of the electronically controlled resistor, thereby achieving the above-mentioned technical results.

[0158] according to Figure 2 The function of the controller of the present invention used for electronically controlling resistor 222 is as follows.

[0159] When the control action changes, that is, when the variable control resistor R... c When the resistance of a (e.g., a digital potentiometer) changes, the voltage U Rc The first summation value is S1 = K'*U Rc The voltage from this resistor is transmitted through amplifier 204 with a transmission coefficient K' to the first input terminal of adder 206. The second voltage, represented by voltage U2, and S2 are transmitted from the sensing resistor R. sense The second input terminal of adder 206 is transmitted through buffer stage 210, R sense It is part of the electronically controlled resistor 222 controlled by the proposed controller 220. The voltage is determined by formula (3), i.e., U2 = I0 * R sense Therefore, S2 = I0 * R sense (See formula (4)), where R sense It is the value of the sensing resistor, which should be as small as possible during implementation.

[0160] As shown in the figure above, the voltage U2 is equal to the current I0 flowing through the electronically controlled resistor 222 and the sensing resistor R. sense The voltage drop caused by this. In reality, due to the potential difference U1 between the high-potential terminal 10 and the low-potential terminal 12 of the electronically controlled resistor 222, the current I0 flows through the following link: high-potential terminal 10 of the electronically controlled resistor 222 - active element 224 - sensing resistor R connected in series with the active element 224. sense -Low potential terminal 12 of electronically controlled resistor 222.

[0161] Therefore, the voltage К'*U Rc Adding it to U2, that is

[0162] К'*U Rc =S1 and U2=S2=I0*R sense ,

[0163] An intermediate signal is generated at the output of adder 206:

[0164] S = S1 + S2 = K' * U Rc +I0*Rsense, (11)

[0165] Then it is received by the inverting input of the operational amplifier 208.

[0166] At the same time, a constant potential U1' is transferred from terminal 6 of device 220 through bias resistor R. bias and reference resistor R ref The voltage divider formed is transmitted to the non-inverting input of operational amplifier 208, which is equal to (see equation (1)):

[0167] U1'=U1 / (1+R bias / R ref ).

[0168] The difference between S and U1' is transmitted from the output of operational amplifier 208 to the third terminal 3 of pseudo-controller 220, which is used to connect the control terminal of active element 224, which is part of electronic control resistor 222, i.e., the output of pseudo-controller 220, because the control voltage Ucontr (Ucontr = U1' - S) is transmitted from the output of pseudo-controller 220 to the control terminal of active element 224.

[0169] However, if the intermediate signal S at the output of adder 206 is higher than the voltage U1', the voltage Ucontr at the control terminal of active element 224 will cause active element 224 to partially close, thereby reducing the current I0 and causing the voltage U2 to drop. Voltage U2 serves as the second voltage, and S2 = I0 * R. senseThe voltage U2 is transmitted through buffer stage 210 to the second input terminal of adder 206, as shown in equation (4). Furthermore, voltage U2 is transmitted to control input terminal 24 of controllable current generator 212, which moderates its current Icg = U2 * Gcg = I0 * R according to formula (6). sense *Gcg, where Gcg is the coefficient that controls the conversion of voltage U2 into current, and is equal to the conductivity.

[0170] The softened current Icg of the controllable current generator 212 causes a softened voltage drop across the variable control resistor Rc (e.g., a digital potentiometer), and therefore, after being amplified by K' times in amplifier 204, it causes a softened first summation at the first input of adder 206 (see equations (2) and (6)):

[0171] S1=К'*Icg*Rс=I0*R sense *Gcg*К'*Rс (12)

[0172] The sums of S1 and S2 are summed in adder 206, and an intermediate signal S is generated at the output of adder 206, as shown in equation (7): S = I0 * R sense *(1+K'*Rс*Gcg).

[0173] As mentioned above, the intermediate signal S slows down as the current I0 decreases.

[0174] Because the operational amplifier 208 has a high amplification factor, this process will continue until the intermediate signal S at the inverting input of the operational amplifier 208 is equal to the voltage U1' at the non-inverting input of the operational amplifier 208.

[0175] Conversely, if the intermediate signal S at the output of adder 206 is lower than voltage U1', the control terminal voltage Ucontr of active element 224 will cause active element 224 to be half-open, increasing current I0 and causing voltage U2 to rise. Voltage U2 serves as the second voltage, and S2 = I0 * R. sense (See equation (4)) is transmitted to the second input terminal of adder 206 via buffer stage 210. Furthermore, voltage U2 is transmitted to control input terminal 24 of controllable current generator 212, increasing its current Icg = U2 * Gcg = I0 * R according to equation (6). sense *Gcg.

[0176] The total S1 will also increase, as shown in equation (12): S1 = I0 * R sense *Gcg*К'*R с

[0177] S1 and S2 are added in adder 206, and an intermediate signal S described by equation (7) is generated at the output of adder 206. As mentioned above, the intermediate signal increases with the increase of current I0.

[0178] Because the operational amplifier 208 has a high amplification factor, this process will continue until the intermediate signal S at the inverting input terminal of the operational amplifier 208 is equal to the voltage U1' at the non-inverting input terminal of the operational amplifier 208, that is, S = U1'.

[0179] Therefore, due to the high-gain feedback looping between operational amplifier 208, active element 224 of electronic control resistor 222, sense resistor Rsense, buffer stage 210, adder 206, and operational amplifier 208, the relationship S = U1' is always true and has practical accuracy for the claimed invention.

[0180] Alternatively, by substituting the corresponding values ​​from (1) and (11), we can obtain formula (8):

[0181] U1*R ref / (R ref +R bias )=I0*R sense *(1+K'*Rс*Gcg)

[0182] Thanks to the high-gain feedback, equation (8) can be reliably achieved even under various unstable factors (including wide temperature fluctuations).

[0183] Considering that the resistance R0 between the high-potential terminal 10 and the low-potential terminal 12 of the electronically controlled resistor 222 is the quotient of the voltage U1 and the current I0 flowing through this chain (high-potential terminal 10 - active element 224 - sensing resistor Rsense connected in series with active element 224 - low-potential terminal 12), then

[0184] R0=U1 / I0 (13)

[0185] Based on the relationship between (8) and (13), the resistance between the high-potential terminal 10 and the low-potential terminal 12 of the electronically controlled resistor 222 can be obtained:

[0186] R0 = U1 / I0 = R sense *(1+K'*Rс*Gcg) / (1+R bias / R ref ),

[0187] Corresponding to formula (9).

[0188] Therefore, by generating a value such as (7)S=I0*R at the output of adder 206 senseThe intermediate signal of *(1+K'*Rс*Gcg) is forwarded to the second (inverting) input of operational amplifier 208, and the transfer potential (see equation (1)) is: U1'=U1 / (1+R bias / R ref The resistance R0 of the electronically controlled resistor 222 of this disclosure is connected to the first (non-inverting) input terminal of the operational amplifier 208, and the equality relationship S=U1' is true due to the high gain feedback. sense The resistance is directly proportional to the control action, which corresponds to the variable control resistor R. c The resistance of (e.g., a digital potentiometer).

[0189] Equation (9) implies that, with a relatively large current I0 provided by the active element 224, it is possible to obtain low and ultra-low R0 values. Therefore, in order to control the resistance of the circuit section, a control action corresponding to the resistance value of the variable control resistor Rc (e.g., a digital potentiometer) can be used, wherein the resistance value of the electronic control resistor 222 is proportional to the control action corresponding to the resistance value of the variable resistor Rc (e.g., a digital potentiometer).

[0190] exist Figure 3 In the controllable current generator 212, the following components are included:

[0191] -302- The second operational amplifier;

[0192] -303- The third operational amplifier;

[0193] -311- The first MOSFET transistor;

[0194] -312- The second MOSFET transistor;

[0195] -Rcg1- The first resistor of the controllable current generator 212;

[0196] -Rcg2- The second resistor of the controllable current generator 212;

[0197] -Rcg3- The third resistor of the controllable current generator 212;

[0198] Figure 3 The controllable current generator 212 in the middle has the following functions.

[0199] Signal S2 (the control signal of the controllable current generator 212) is transmitted to control input 24 and then forwarded to the non-inverting input (+) of the second operational amplifier 302, wherein the output of the operational amplifier 302 is connected to the gate of the first MOSFET transistor 311. The source of the first MOSFET transistor 311 is connected to the inverting input (-) of the second operational amplifier 302 and the first terminal of the first resistor Rcg1 of the controllable current generator 212. The second terminal 28 of the first resistor Rcg1 is connected to the low-potential terminal 12 of the electronically controlled resistor (see also). Figure 2 Current Icg1 flows through the drain-source chain of the first MOSFET transistor 311, generating a voltage drop across the first resistor Rcg1 of the controllable current generator 212.

[0200] Ucg1=Icg1*Rcg1(14)

[0201] Since there is a high-gain feedback loop around both the second operational amplifier 302 and the first MOSFET transistor 311, the signal S2 at the non-inverting input (+) and the voltage Ucg1 at its inverting input (-) of the second operational amplifier 302 can be considered equal in practical applications. Therefore:

[0202] S2=Ucg1 (15)

[0203] Therefore, the current flowing through the first MOSFET transistor 311 is

[0204] Icg1=S2 / Rcg1 (16)

[0205] And a voltage drop is generated across the second resistor Rcg2 of the controllable current generator 212:

[0206] Ucg2=Icg1*Rcg2 (17)

[0207] Since the first terminal of the second resistor Rcg2 is connected to terminal 22 of the controllable current generator 212 that receives the power supply voltage E, and the second terminal of the second resistor Rcg2 is connected to the non-inverting input (+) of the third operational amplifier 303, the following voltage will be generated here:

[0208] U +303 =Е-Ucg2 (18)

[0209] The output of the third operational amplifier 303 is connected to the gate of the second MOSFET transistor 312. The drain of the transistor is connected to the inverting input (-) of the third operational amplifier 303 and the first terminal of the third resistor Rcg3. The second terminal of the third resistor Rcg3 is connected to the terminal 22 of the controllable current generator 212, which receives the power supply voltage E.

[0210] The output current Icg of the controllable current generator 212 flows to the terminal 26 of the controllable current generator 212 through the drain-source chain of the second MOSFET transistor 312, causing a voltage drop across the third resistor Rcg3 of the controllable current generator 212.

[0211] Ucg3=Icg*Rcg3 (19)

[0212] Therefore, the inverting input (-) of the third operational amplifier 303 will receive the following voltage from the first terminal of the third resistor Rcg3:

[0213] U -303 =Е-Ucg3 (20)

[0214] Since there is a high-gain feedback loop around both the third operational amplifier 303 and the second MOSFET transistor 312, the voltages at the non-inverting input (+) and the inverting input (-) of the third operational amplifier 303 can be considered equal in practical applications. Therefore:

[0215] U +303 =U -303 (twenty one)

[0216] Therefore, see (18) and (20):

[0217] Ucg2=Ucg3 (22)

[0218] Considering (17) and (19),

[0219] Icg1*Rcg2=Icg*Rcg3 (23)

[0220] Therefore, the output current Icg of the controllable current generator 212 is

[0221] Icg=Icg1*Rcg2 / Rcg3 (24)

[0222] Since Icg1 depends on the control signal S2 (see formula (16)), the result is

[0223] Icg=S2*Rcg2 / (Rcg1*Rcg3) (25)

[0224] Alternatively, since signal S2 is equal to the signal from the sensing resistor R sense The voltage U2 received by (part of the electronically controlled resistor 222) is therefore the final result is

[0225] Icg=U2*Rcg2 / (Rcg1*Rcg3) (26)

[0226] The current is independent of the resistance value of the variable control resistor Rc outside the controllable current generator 212, but depends only on the internal resistance value of the resistor in the controllable current generator 212 and the control voltage U2 on the sensing resistor Rsense.

[0227] numerical values

[0228] Gcg=Rcg2 / (Rcg1*Rcg3) (27)

[0229] A coefficient characterizing the conversion of control voltage U2 into a current equal to conductivity is used when determining the resistance of electronically controlled resistor 222 according to this disclosure. Therefore, for example, according to... Figure 3 The designed controllable current generator 212 enables the proposed controller 220 to function in order to achieve the aforementioned technical results.

[0230] Controllable current generators can be implemented in various ways, for example, as described in "LT1789. Micropower, Single-Supply Rail-to-Rail Output Instrumentation Amplifier" (LINEARTECHNOLOGY CORPORATION 2002, drawing "0.5A to 4A Voltage Controllable Current Source") (see also...)

[0231] (https: / / www.analog.com / ru / products / lt1789.html#product-overview).

[0232] A controllable current generator can also achieve this; for example, refer to the article "How to design a 4-20mA variable current source with a 24Vdc input?" (See ElectricalEngineeringStackExchange or https: / / electronics.stackexchange.com / questions / 72192 / how-should-i-design-variable-currentsource-of-4-20mA-with-24Vdc-input?rq=1).

[0233] The controllable current generator 212 can also be designed based on the integrated circuit LT6552, as shown in Jim Williams' 2013 paper "Voltage-Controlled Current Source - Ground Reference Input and Output" published in Analog Circuit Design (https: / / www.sciencedirect.com / topics / engineering / controlled-current-source), as well as many other options.

[0234] The voltage divider can be a resistive voltage divider, a voltage divider consisting of two transistors connected in series, or any other type that allows a portion of the voltage from the high-potential terminal 10 of the electronically controlled resistor 222 to be forwarded to the non-inverting input of the operational amplifier 208.

[0235] The voltage divider can also be externally connected to the controller 220 and connected to the controller 220 through a separate terminal, thus avoiding the supply of voltage to the controller 220 from the high-potential terminal 10 of the electronic control resistor 222.

[0236] Amplifier 204, buffer stage 210 and adder 206 can be implemented in different ways, thereby giving the proposed device different performance characteristics.

[0237] The controller 220 can be constructed from standard discrete components or integrated circuits (such as operational amplifiers, transistors, and resistors) (including ASICs). For example, amplifier 204, buffer stage 210, and controllable current generator 212 can be manufactured using integrated circuits such as OPA189, TLV9002IDR, and MCP6002-E / SN. The primary parameter is preferably the open-loop gain (Ro). L =10kΩ) at least 100dB; gain-bandwidth product at least 1MHz, rail-to-rail input and output. Operational amplifier 208 can also use similar components. The transistor used as the controllable current generator 212 can be the NTNUS3171PZ, NX3020NAK, or similar components, with parameter R... DS (on) can reach up to 5.5 Ohm, and the drain current I0 is at least 100mA.

[0238] Other components of the electronically controlled resistor 222 (e.g., adder 206, voltage source 214) are well known in the art and can be implemented in any known manner.

[0239] The nominal values ​​of the resistors are as follows:

[0240] R bias The range is 100...200 KOhm;

[0241] R ref Within the range of 50...100 KOhm.

[0242] Rcg1, Rcg2, and Rcg3 are typically between 200 Ohm and 1 KOhm.

[0243] Rsense depends on the rated expected value of the electronically controlled resistor 222, typically 10 milliohms or higher (e.g., up to 100 Ohms). The STT6N3LLH6 transistor or the like can be used as an active element, provided its Rsense... DS(on) should be one order of magnitude smaller than the nominal value of the electronically controlled resistor 222.

[0244] For example, the proposed controller 220 for the electronically controlled resistor 222 can be fabricated as a chip, chip assembly, or microplate. Similarly, the electronically controlled resistor 222 can also be fabricated as a chip, chip assembly, or microplate.

[0245] A preferred embodiment of the controller 220 for the electronically controlled resistor 222 is in the form of an integrated circuit, which allows for a significant reduction in size and manufacturing cost. For relatively low-power electronically controlled resistors (the total power dissipated by the active element and the sensing resistor does not exceed 1-2 watts), it is preferable to implement the controller, active element, and sensing resistor as a single integrated circuit. In any case, the voltage divider can be external or internal.

[0246] right Figure 2 and Figure 3 The proposed controller 220 was prototyped to confirm that the objectives of the invention are achievable.

[0247] The prototype design results are as follows:

[0248] Power supply voltage: 5V±5%;

[0249] Minimum resistance of a variable control resistor Rc (e.g., a digital potentiometer): 100 Ohm;

[0250] Maximum resistance of a variable control resistor Rc (such as a digital potentiometer): 10,000 Ohm;

[0251] The minimum resistance R of the electronically controlled resistor 0min 383.5 Ohm;

[0252] The maximum resistance R of the electronically controlled resistor 0max 26225.9 Ohm;

[0253] The electronically controlled resistor has a resistance adjustment range of 68.4x.

[0254] The resistance of electronically controlled resistor 222 and resistance R c The nonlinear relationship between (such as digital potentiometers) does not exceed 1.4%.

[0255] The resistance R0 of the electronically controlled resistor 222 and the variable control resistor R c The relationship between the resistance R0 and the resistance R0 is in Figure 4 The reading is displayed as a straight line. The measured resistance value is indistinguishable from the predicted / estimated value.

[0256] Therefore, it can be seen that the present invention has successfully achieved the above-mentioned technical results.

[0257] However, the present invention is not limited thereto.

[0258] Having described a preferred embodiment, those skilled in the art should clearly see that certain advantages of the method and apparatus have been achieved.

[0259] While the invention has been described in conjunction with exemplary embodiments which are now considered practical, it should be understood that the invention is not limited to the disclosed embodiments, but rather is intended to cover various modifications and equivalent arrangements within the spirit and scope of the appended claims.

[0260] The accompanying drawings and descriptions of this invention are illustrative only and do not limit the scope of its implementation.

[0261] The present invention is further defined by the claims.

Claims

1. A controller (220) for an electronically controlled resistor (ECR) (222), comprising: First operational amplifier (208), reference resistor (Rref), constant voltage source (214). The first terminal (1) of the controller (220) is used to connect to the first terminal of an external variable control resistor (Rc). The second terminal (2) of the controller (220) is used to receive feedback signals from the common node of the external sensing resistor (Rsense) and the external active element (224). The third terminal (3) of the controller (220) is used to connect to the control terminal of an external active component (224). The fourth terminal (4) of the controller (220) is used to connect to the second terminal of an external variable control resistor (Rc). The fifth terminal (5) of the controller (220) is used to connect to the low-potential terminal (12) of the electronic control resistor (222), and the sixth terminal (6) of the controller (220) is used to connect to the high-potential terminal (10) of the electronic control resistor (222). The output of the first operational amplifier (208) is connected to the third terminal (3) of the controller (220). The first terminal of the reference resistor (Rref) is connected to the non-inverting input of the first operational amplifier (208), and the second terminal of the reference resistor (Rref) is connected to the fifth terminal (5) of the controller (220). The controller (220) is characterized in that it further includes a bias resistor (Rbias), the first terminal of which is connected to the sixth terminal (6) of the controller (220), and the second terminal is connected to the non-inverting input terminal of the first operational amplifier (208). Adder (206), the first input terminal of adder (206) is used to connect to the first terminal (1) of controller (220), the second input terminal of adder (206) is used to connect to the second terminal (2) of controller (220), and the output terminal of adder (206) is connected to the inverting input terminal of first operational amplifier (208). A controllable current generator (212) includes a second operational amplifier (302), a third operational amplifier (303), a first transistor (311), a second transistor (312), a first resistor (Rcg1), a second resistor (Rcg2), and a third resistor (Rcg3). The control input terminal (24) of the controllable current generator (212) is connected to the second terminal (2) of the controller (220) and the non-inverting input terminal of the second operational amplifier (302). The inverting input terminal of the second operational amplifier (302) is connected to the common node of the first transistor (311) and the first resistor (Rcg1) connected in series. The output terminal of the second operational amplifier (302) is connected to the gate of the first transistor (311). The output terminal (26) of the controllable current generator (212) is connected to the first terminal (1) of the controller (220), the inverting input terminal of the first operational amplifier (208), and the second transistor (312). The output terminal of the third operational amplifier (303) is connected to the gate of the second transistor (312). The non-inverting input terminal of the third operational amplifier (303) is connected to the common node of the first transistor (311) and the series-connected second resistor (Rcg2), and the inverting input terminal of the third operational amplifier 303 is connected to the common node of the second transistor 312 and the series-connected third resistor Rcg3. The common node of the second resistor (Rcg2) and the third resistor (Rcg3) is connected to the terminal (22) of the controllable current generator (212), which is intended to connect to a constant voltage source (214) to power the controllable current generator. The fourth terminal (4) and the fifth terminal (5) of the controller (220) are connected to each other, and the constant voltage source (214) is connected to the terminal (22) of the controllable current generator (212).

2. The controller (220) according to claim 1 further includes a buffer stage (210) connected between the second terminal (2) of the controller (220) and the control input terminal (24) of the controllable current generator (212), the output terminal of the buffer stage (210) being connected to the second input terminal of the adder (206).

3. The controller (220) according to claim 1 further includes an amplifier (204) connected between a first terminal (1) of the controller (220) and a first input terminal of the adder (206).

4. An electronically controlled resistor (ECR) (222) for use with a variable control resistor (Rc), the electronically controlled resistor (ECR) (222) for use with a variable control resistor (Rc) comprising: The series connection of a high-potential terminal (10), an active element (224), a sensing resistor (Rsense), and a low-potential terminal (12) is characterized in that... The electronically controlled resistor (222) also includes the controller (220) of claim 1. The high-potential terminal (10) of the electronically controlled resistor (222) is connected to the sixth terminal (6) of the controller (220). The low-potential terminal (12) of the electronically controlled resistor (222) is connected to the fifth terminal (5) of the controller (220). The control terminal of the active component (224) is connected to the third terminal (3) of the controller (220). The common node of the sensing resistor (Rsense) and the active element (224) is connected to the second terminal (2) of the controller (220). The first terminal (1) of the controller (220) is used to connect to the first terminal of an external variable control resistor (Rc). The fourth terminal (4) of the controller (220) is used to connect to the second terminal of an external variable control resistor (Rc).

5. The electronically controlled resistor (222) according to claim 4, wherein the active element (224) is a transistor.

6. An integrated circuit (IC) for a controller (220) of an electronically controlled resistor (222), Integrated circuits include: The first operational amplifier (208), the reference resistor (Rref), and the bias resistor (Rbias) The first terminal (1) of the integrated circuit is used to connect to the first terminal of an external variable control resistor (Rc). The second terminal (2) of the integrated circuit is used to receive feedback signals from the common node of the external sense resistor (Rsense) and the external active element (224). The third terminal (3) of the integrated circuit is used to connect to the control terminal of an external active component (224). The fourth terminal (4) of the integrated circuit is used to connect to the second terminal of an external variable control resistor (Rc). The fifth terminal (5) of the integrated circuit is used to connect to the low-potential terminal (12) of the electronic control resistor (222). The sixth terminal (6) of the integrated circuit is used to connect to the high-potential terminal (10) of the electronic control resistor (222). The controllable current generator (212) includes a second operational amplifier (302), a third operational amplifier (303), a first transistor (311), a second transistor (312), a first resistor (Rcg1), a second resistor (Rcg2), and a third resistor (Rcg3). The control input terminal (24) of the controllable current generator (212) is connected to the second terminal (2) of the integrated circuit and the non-inverting input terminal of the second operational amplifier (302). The inverting input terminal of the second operational amplifier (302) is connected to the common node of the first transistor (311) and the first resistor (Rcg1) connected in series. The output terminal of the second operational amplifier (302) is connected to the gate of the first transistor (311). The output terminal (26) of the controllable current generator (212) is connected to the first terminal (1) of the integrated circuit, the inverting input terminal of the first operational amplifier (208), and the second transistor (312). The output terminal of the third operational amplifier (303) is connected to the gate of the second transistor (312). The non-inverting input of the third operational amplifier (303) is connected to the common node of the first transistor (311) and the second resistor (Rcg2) in series. The inverting input of the third operational amplifier 303 is connected to the common node of the second transistor 312 and the series-connected third resistor Rcg3. The output of the first operational amplifier (208) is connected to the third terminal (3) of the integrated circuit. The first terminal of the reference resistor (Rref) is connected to the non-inverting input of the first operational amplifier (208), and the second terminal of the reference resistor (Rref) is connected to the fifth terminal (5) of the integrated circuit. The first terminal of the bias resistor (Rbias) is connected to the sixth terminal (6) of the integrated circuit, and the second terminal of the bias resistor (Rbias) is connected to the non-inverting input terminal of the first operational amplifier (208). The fourth terminal (4) and the fifth terminal (5) of the integrated circuit are interconnected.

7. Integrated circuit (IC) for electronic control resistor (222) controller (220). The integrated circuit includes: The first terminal (1) of the integrated circuit is used to connect to the first terminal of an external variable control resistor (Rc). The second terminal (2) of the integrated circuit is used to receive feedback signals from the common node of the external sensing resistor (Rsense) and the external active element (224). The third terminal (3) of the integrated circuit is used to connect to the control terminal of an external active component (224). The fourth terminal (4) of the integrated circuit is used to connect to the second terminal of an external variable control resistor (Rc). The fifth terminal (5) of the integrated circuit is used to connect to the low-potential terminal (12) of the electronic control resistor (222). The sixth terminal (6) of the integrated circuit is used to connect to the high-potential terminal (10) of the electronic control resistor (222). The additional terminals of the integrated circuit are designed to connect to an external voltage divider, which includes a bias resistor (Rbias) and a reference resistor (Rref), connected in series between the high-potential terminal (10) and the low-potential terminal (12) of the electronically controlled resistor (222). First operational amplifier (208) and controllable current generator (212). The controllable current generator (212) includes a second operational amplifier (302), a third operational amplifier (303), a first transistor (311), a second transistor (312), a first resistor (Rcg1), a second resistor (Rcg2), and a third resistor (Rcg3). The control input terminal (24) of the controllable current generator (212) is designed to connect to the second terminal (2) of the integrated circuit and the non-inverting input terminal of the second operational amplifier (302). The inverting input terminal of the second operational amplifier (302) is connected to the common node of the first transistor (311) and the first resistor (Rcg1) connected in series. The output terminal of the second operational amplifier (302) is connected to the gate of the first transistor (311). The output terminal (26) of the controllable current generator (212) is designed to connect to the first terminal (1) of the integrated circuit, the inverting input terminal of the first operational amplifier (208), and the second transistor (312). The output terminal of the third operational amplifier (303) is connected to the gate of the second transistor (312). The non-inverting input of the third operational amplifier (303) is connected to the common node of the first transistor (311) and the second resistor (Rcg2) in series, and The inverting input of the third operational amplifier 303 is connected to the common node of the second transistor 312 and the series-connected third resistor Rcg3. The non-inverting input of the first operational amplifier (208) is designed to connect to an additional terminal of the integrated circuit. The output of the first operational amplifier (208) is connected to the third terminal (3) of the integrated circuit. The fourth terminal (4) and the fifth terminal (5) of the integrated circuit are interconnected inside the integrated circuit.

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