Operational amplifier power supply adjusting circuit

Abstract

The utility model discloses an operational amplifier power supply adjusting circuit comprising an operational amplifier tube which is provided with a power supply end and an output end; the first current converter is provided with an input end, an output end and a control end, the input end of the first current converter is coupled with a first power supply, and the output end of the first current converter is coupled with the power supply end of the operational amplifier tube; the first digital potentiometer is provided with a first end, a second end and a third end, the first end of the first digital potentiometer receives a first control signal, and the second end and the third end of the first digital potentiometer are both coupled to the control end of the first current converter. When the voltage difference between the power supply voltage of the operational amplifier tube and the voltage output by the operational amplifier tube is large, the difference between the power supply voltage and the voltage output by the operational amplifier tube can be reduced, the problem of overhigh temperature or temperature drift of the operational amplifier tube caused by overlarge voltage difference is avoided, the gain of the operational amplifier can be optimized, the signal-to-noise ratio and the sensitivity of the circuit are improved, and the reliability of the circuit is improved. And the service life of the circuit can be prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to a technology field of operational amplifier, especially to a kind of operational amplifier power regulating circuit. BACKGROUND

[0002] Operational amplifier (operational amplifier tube) is an electronic integrated circuit containing multiple-stage amplification circuit, its input stage is differential amplifier circuit, with high input resistance and suppress zero drift capability;Intermediate stage mainly carries out voltage amplification, with high voltage amplification, generally by common emitter amplifier circuit composition;Output pole is connected with load, with strong load capacity, low output resistance characteristics.The most basic function of operational amplifier is to amplify electronic signal, and its output signal can be the result of input signal addition, subtraction or differential, integration and other mathematical operations.

[0003] At present, with the rapid development of semiconductor industry, the demand of equipment for semiconductor testing gradually diversifies, and the output capacity requirement for various test board cards is also higher and higher, but when the voltage difference between the power supply voltage and the output voltage in the board card is too large, the operational amplifier tube will heat seriously, which may cause operational amplifier heat damage or temperature drift and other problems. UTILITY MODEL CONTENT

[0004] The utility model aims at providing a kind of operational amplifier power regulating circuit, to solve the prior art, the power supply voltage of operational amplifier tube is not adjustable, when the voltage difference between power supply voltage and output voltage is too large, operational amplifier tube will heat seriously, which may cause operational amplifier heat damage or temperature drift and other problems.

[0005] To realize one of the above utility model purposes, one embodiment of the utility model provides an operational amplifier power regulating circuit, the circuit includes: operational amplifier tube, with power end and output end, the output end of the operational amplifier tube is used to output first voltage;First current converter, with input end, output end and control end, the input end of the first current converter is coupled first power supply, the output end of the first current converter is coupled to the power end of the operational amplifier tube;First digital potentiometer, with first end, second end and third end, the first end of the first digital potentiometer receives first control signal, the second end and third end of the first digital potentiometer are all coupled to the control end of the first current converter;Wherein, the first control signal is used to adjust the resistance value of the first digital potentiometer, and the first current converter outputs second voltage to the power end of the operational amplifier tube according to the resistance value input at the control end.

[0006] As a further improvement of the utility model, the circuit further includes: control module, the control module is coupled to the first end of the first digital potentiometer;The control module is used to output first control signal to adjust the resistance value of the first digital potentiometer.

[0007] As a further improvement of the utility model, the circuit further includes: the first fixed value resistance has a first end and a second end, the first end of the first fixed value resistance is coupled with the second end and the third end of the first digital potentiometer, and the second end of the first fixed value resistance is coupled with the control end of the first current converter.

[0008] As a further improvement of the utility model, the circuit further includes: the power end of the operational amplifier tube includes a positive power pin, and the output end of the first current converter is coupled with the positive power pin of the operational amplifier tube.

[0009] As a further improvement of the utility model, the circuit further includes: the power end of the operational amplifier tube includes a negative power pin, and the output end of the first current converter is coupled with the negative power pin of the operational amplifier tube.

[0010] As a further improvement of the utility model, the circuit further includes: the power end of the operational amplifier tube includes a positive power pin and a negative power pin, the output end of the first current converter is coupled with the positive power pin of the operational amplifier tube, and the operational amplifier power regulating circuit further includes: a second current converter having an input end, an output end and a control end, the input end of the second current converter is coupled with a second power supply, the output end of the second current converter is coupled with the negative power pin of the operational amplifier tube, a second digital potentiometer having a first end, a second end and a third end, the first end of the second digital potentiometer receives a first control signal, and the second end and the third end of the second digital potentiometer are both coupled to the control end of the second current converter, wherein the first control signal is also used to adjust the resistance value of the second digital potentiometer, and the second current converter outputs a third voltage to the negative power pin of the operational amplifier tube according to the resistance value input at the control end.

[0011] As a further improvement of the utility model, the circuit further includes: the second fixed value resistance has a first end and a second end, the first end of the second fixed value resistance is coupled with the second end and the third end of the second digital potentiometer, and the second end of the second fixed value resistance is coupled with the control end of the second current converter.

[0012] As a further improvement of the utility model, the circuit further includes: a control module, the control module is coupled with the first end of the first digital potentiometer and the first end of the second digital potentiometer, the control module is used for outputting a first control signal to adjust the resistance value of the first digital potentiometer, and the control module is also used for outputting a second control signal to adjust the resistance value of the second digital potentiometer.

[0013] As a further improvement of the utility model, the circuit further comprises: the operational amplifier tube is configured to receive the second voltage at the positive power supply pin or the third voltage at the negative power supply pin as the power supply voltage of the operational amplifier tube.

[0014] As a further improvement of the utility model, the circuit further comprises: the first current converter is a direct current converter.

[0015] Compared with the prior art, the utility model has the beneficial effects that: the resistance value of the first current converter is adjusted through the first digital potentiometer, thereby indirectly adjusting the voltage output by the first current converter, the power supply end voltage of the operational amplifier tube, that is, the power supply voltage of the operational amplifier tube, can reduce the difference between the power supply voltage and the first voltage output by the operational amplifier tube when the voltage difference is large, thereby avoiding the problem of excessive temperature or temperature drift of the operational amplifier tube caused by the excessively large voltage difference, and the gain of the operational amplifier can be optimized, the signal-to-noise ratio and sensitivity of the circuit are improved, and the service life of the circuit is prolonged. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is the circuit structure schematic view of the operational amplifier power supply adjusting circuit in an embodiment of the utility model.

[0017] Figure 2 is the circuit structure schematic view of the operational amplifier power supply adjusting circuit in another embodiment of the utility model.

[0018] Figure 3 is the circuit structure schematic view of the operational amplifier power supply adjusting circuit in still another embodiment of the utility model. DETAILED DESCRIPTION

[0019] The utility model will be described in detail in combination with the specific implementation mode shown in the drawings. But these implementation modes do not limit the utility model, and the conversion of structure, method or function made by the ordinary skilled in the art according to these implementation modes is included in the protection scope of the utility model.

[0020] The utility model provides a kind of operational amplifier power supply adjusting circuit, for adjusting the power supply voltage of operational amplifier (operational amplifier tube A), to solve the possible of the voltage pressure difference of operational amplifier tube A power supply voltage fixed condition is too large, cause operational amplifier tube A overheating damage or gain reduction.

[0021] In some implementation scenarios, such as in semiconductor testing, operational amplifier tube A is used to process various analog signals in semiconductor test equipment, and testers can realize different test functions, such as signal amplification, filtering, comparison, etc. by configuring the external circuit of operational amplifier.

[0022] As Figure 1 andFigure 2 The utility model provides an operational amplifier power supply adjusting circuit, which comprises an operational amplifier A, a first current converter 1 and a first digital potentiometer 3.

[0023] The operational amplifier A can amplify the amplitude of an input signal and output the amplified signal. Specifically, the first input end and the second input end of the operational amplifier A are both input with a signal (such as a voltage signal), and the operational amplifier A outputs a first voltage V1.

[0024] The power supply end of the operational amplifier A is used to receive an external voltage for stable operation of the operational amplifier A.

[0025] The operational amplifier power supply adjusting circuit further comprises the first current converter 1 and the first digital potentiometer 3.

[0026] The first current converter 1 is used for current conversion. In an embodiment, the first current converter 1 is a direct current converter. Specifically, the first current converter 1 is a direct current-direct current converter, which converts one direct current voltage into another different direct current voltage.

[0027] The first current converter 1 has an input end, an output end and a control end. The input end of the first current converter 1 is coupled to a first power supply, and the output end of the first current converter 1 is coupled to the power supply end of the operational amplifier A.

[0028] The first power supply is used to supply power to the first current converter 1 and provide a basic voltage for the first current converter 1. The first current converter 1 outputs a second voltage V2 based on the voltage value of the first power supply.

[0029] V2 = X / R + A;

[0030] Wherein, X is a constant value; R is the resistance value at the control end of the first current converter 1; A is determined by the first power supply itself and is regarded as a constant value.

[0031] The first digital potentiometer 3 is controlled by digital input and generates an analog output. It is usually composed of a digital controller, a resistance element and a switching circuit inside. The digital controller can generate an instruction signal to control the switching circuit, and the switching circuit controls the connection mode of the resistance element, thereby changing the resistance value of the first digital potentiometer 3.

[0032] The first digital potentiometer 3 has a first end, a second end and a third end. The first end of the first digital potentiometer 3 receives a first control signal S1, and the second end and the third end of the first digital potentiometer 3 are both coupled to the control end of the first current converter 1.

[0033] The first control signal S1 is used to adjust the resistance value of the first digital potentiometer 3. The first current converter 1 outputs a second voltage V2 to the power supply end of the operational amplifier A according to the resistance value input at the control end.

[0034] The size of the second voltage V2 changes according to the change of the resistance value of the first digital potentiometer 3. In an embodiment, V1=X / R+A, where R is the resistance value of the first digital potentiometer 3.

[0035] In this embodiment, the size of the first voltage V1 output by the operational amplifier A is monitored, and the voltage difference between the first voltage V1 and the second voltage V2 is calculated based on the size of the second voltage V2. When the voltage difference is large, such as greater than a set threshold, the resistance value of the first digital potentiometer 3 is adjusted by using the first control signal S1, and the second voltage V2 output by the first current converter 1 is adjusted to reduce the voltage difference between the first voltage V1 and the second voltage V2.

[0036] In this way, when the voltage difference between the power supply voltage of the operational amplifier A and the voltage output by the operational amplifier A is large, the difference between the two can be reduced, avoiding the problem of excessive temperature or temperature drift of the operational amplifier A caused by excessive voltage difference. Also, the gain of the operational amplifier can be optimized, the signal-to-noise ratio and sensitivity of the circuit are improved, and the service life of the circuit is prolonged.

[0037] In an embodiment of the utility model, the operational amplifier power supply adjusting circuit further comprises a control module M, the control module M is coupled with the first end of the first digital potentiometer 3. The control module M is used to output the first control signal S1 to adjust the resistance value of the first digital potentiometer 3.

[0038] The control module M outputs the first control signal S1 according to an external instruction, indicating the first digital potentiometer 3 to change its own resistance value. The control module M can be a host computer, and the external instruction can be an instruction issued manually from the host computer, which includes the resistance value of the first digital potentiometer 3 to be adjusted, so that the first digital potentiometer 3 adjusts its own resistance value to meet the requirements.

[0039] In an embodiment of the utility model, the operational amplifier power supply adjusting circuit further comprises a first fixed resistance R1, the first fixed resistance R1 has a first end and a second end, the first end of the first fixed resistance R1 is coupled with the second end and the third end of the first digital potentiometer 3, and the second end of the first fixed resistance R1 is coupled with the control end of the first current converter 1.

[0040] The magnitude of the second voltage V2 varies according to the resistance of the first digital potentiometer 3 and the first fixed resistor R1. In one embodiment, V1=X / R+A, where R is the sum of the resistance of the first digital potentiometer 3 and the first fixed resistor R1.

[0041] In this way, the setting of the first fixed resistor R1 can ensure that the resistance value at the control terminal of the first current converter 1 has a minimum limit, thereby ensuring that the first current converter 1 can output a relatively safe second voltage V2.

[0042] In one embodiment of the present invention, the power supply terminal of the operational amplifier tube A includes a positive power supply pin VCC, and the output terminal of the first current converter 1 is coupled to the positive power supply pin VCC of the operational amplifier tube A.

[0043] The second voltage V2 output by the first current converter 1 provides a positive phase voltage to the operational amplifier tube A.

[0044] Specifically, the first current converter 1 includes a positive power supply chip, which outputs the second voltage V2 to the positive power supply pin VCC of the operational amplifier tube A.

[0045] The positive power pin VCC of the operational amplifier tube A only corresponds to the positive power chip in the first current converter 1 . In other embodiments, the positive power pin VCC of the operational amplifier tube A can also be expressed as the first power pin.

[0046] In one embodiment of the present invention, the power supply terminal of the operational amplifier tube A includes a negative power supply pin VSS, and the output terminal of the first current converter 1 is coupled to the negative power supply pin VSS of the operational amplifier tube A.

[0047] The second voltage V2 output by the first current converter 1 provides a negative phase voltage to the operational amplifier tube A.

[0048] Specifically, the first current converter 1 includes a negative power chip, which outputs a second voltage V2 to the negative power pin VSS of the operational amplifier A.

[0049] The negative power pin VSS of the operational amplifier tube A only corresponds to the negative power chip in the first current converter 1 . In other embodiments, the negative power pin VSS of the operational amplifier tube A may also be expressed as the second power pin.

[0050] like Figure 3 As shown, in one embodiment of the present invention, the op amp power supply regulation circuit further includes a second current converter 2 and a second digital potentiometer 4. The second current converter 2 is the same as the first current converter 1, and the second digital potentiometer 4 is the same as the first digital potentiometer 3, and their principles are not further described here.

[0051] The power supply end of the operational amplifier tube A includes a positive power supply pin VCC and a negative power supply pin VSS, and in other embodiments, the positive power supply pin VCC of the operational amplifier tube A can also be expressed as a first power supply pin, and the negative power supply pin VSS of the operational amplifier tube A can also be expressed as a second power supply pin.

[0052] The output end of the first current converter 1 is coupled to the positive power supply pin VCC of the operational amplifier tube A, and the first current converter 1 outputs a second voltage V2 to the positive power supply pin VCC.

[0053] The second current converter 2 has an input end, an output end and a control end, the input end of the second current converter 2 is coupled to a second power supply, and the output end of the second current converter 2 is coupled to the negative power supply pin VSS of the operational amplifier tube A.

[0054] The second digital potentiometer 4 has a first end, a second end and a third end, the first end of the second digital potentiometer 4 receives a second control signal S2, and the second end and the third end of the second digital potentiometer 4 are both coupled to the control end of the second current converter 2.

[0055] The second control signal S2 is used to adjust the resistance value of the second digital potentiometer 4. The second current converter 2 outputs a third voltage V3 to the negative power supply pin VSS of the operational amplifier tube A according to the resistance value input at the control end.

[0056] In an embodiment of the utility model, the operational amplifier power supply adjusting circuit further includes a second fixed value resistance R2, the second fixed value resistance R2 has a first end and a second end, the first end of the second fixed value resistance R2 is coupled to the second end and the third end of the second digital potentiometer 4, and the second end of the second fixed value resistance R2 is coupled to the control end of the second current converter 2.

[0057] As same as in the above embodiment, here, the resistance value of the control end of the second current converter 2 is the sum of the resistance value of the second digital potentiometer 4 and the resistance value of the second fixed value resistance R2.

[0058] In an embodiment of the utility model, the control module M is coupled to the first end of the first digital potentiometer 3 and the first end of the second digital potentiometer 4, the control module M is used to output a first control signal S1 to adjust the resistance value of the first digital potentiometer 3, and the control module M is also used to output a second control signal S2 to adjust the resistance value of the second digital potentiometer 4.

[0059] In an embodiment of the utility model, the operational amplifier tube A is configured to receive the second voltage V2 at the positive power supply pin VCC or the third voltage V3 at the negative power supply pin VSS as the power supply voltage of the operational amplifier tube A.

[0060] In an embodiment, the positive supply pin VCC of the operational amplifier tube A receives the second voltage V2 or the negative supply pin VSS receives the third voltage V3 at the same time.

[0061] Specifically, the first current converter 1 has a positive supply chip, and the second current converter 2 has a negative supply chip, which can output corresponding positive voltage or negative voltage according to the use demand of the user. The positive supply chip and the negative supply chip will only output one voltage value (the second voltage V2 or the third voltage V3) at the same time, which is used as the power voltage of the operational amplifier tube A for the operational amplifier tube A to work.

[0062] In this embodiment, the size of the first voltage V1 output by the operational amplifier tube A is monitored, and the voltage difference between the first voltage V1 and the second voltage V2 or the third voltage V3 is calculated based on the size of the second voltage V2 or the third voltage V3. When the voltage difference is large, such as greater than a set threshold, the resistance value of the first digital potentiometer 3 is adjusted by using the first control signal S1 or the resistance value of the second digital potentiometer 4 is adjusted by using the second control signal S2, so as to reduce the voltage difference between the power voltage of the operational amplifier tube A and the first voltage V1. Through the above setting, the user can control the second voltage V2 or the third voltage V3 according to the use demand. For example, if the positive voltage is needed, the second voltage V2 is adjusted, and if the negative voltage is needed, the third voltage V3 is adjusted, so as to realize the individual control of the output voltage and meet different use scenarios.

[0063] In an embodiment of the utility model, a driving device is also provided, which comprises the operational amplifier power supply adjusting circuit in any of the above embodiments.

[0064] In summary, the utility model provides a kind of operational amplifier power supply adjusting circuit, the resistance value received by first digital potentiometer 3 is adjusted to first current converter 1, so as to change the voltage that first current converter 1 exports to operational amplifier tube A positive power supply pin VCC, reduce the voltage difference between the voltage of operational amplifier tube A positive power supply pin VCC and its output first voltage V1.The utility model provides another kind of operational amplifier power supply adjusting circuit, the resistance value received by first digital potentiometer 3 is adjusted to first current converter 1, so as to change the voltage that first current converter 1 exports to operational amplifier tube A negative power supply pin VSS, reduce the voltage difference between the voltage of operational amplifier tube A negative power supply pin VSS and its output first voltage V1.The utility model also provides a kind of operational amplifier power supply adjusting circuit, the resistance value received by first digital potentiometer 3 is adjusted to first current converter 1, so as to change the voltage that first current converter 1 exports to operational amplifier tube A positive power supply pin VCC;Also by second digital potentiometer 4, the resistance value received by second current converter 2 is adjusted, so as to change the voltage that second current converter 2 exports to operational amplifier tube A negative power supply pin VSS;And by control module M, first current converter 1 and second current converter 2 are controlled to only export one voltage value to operational amplifier tube A at uniform time, reduce the voltage difference between the voltage of operational amplifier tube A negative power supply pin VSS and first voltage V1 or reduce the voltage difference between the voltage of positive power supply pin VCC and first voltage V1.Finally realize the problem that the temperature of operational amplifier tube A is too high or temperature drift caused by avoiding that voltage difference is too large, also can make the gain of operational amplifier tube A be optimized, improve the signal-to-noise ratio and sensitivity of circuit, prolong the service life of circuit.

[0065] It should be understood that, although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be combined appropriately to form other embodiments that those skilled in the art can understand.

[0066] The series of detailed descriptions listed above are only specific descriptions of the feasible embodiments of the utility model, and they are not used to limit the protection scope of the utility model, and equivalent embodiments or changes made without departing from the spirit of the utility model art should be included in the protection scope of the utility model.

Claims

1. An operational amplifier power supply regulation circuit, characterized in that: include: An operational amplifier tube having a power supply end and an output end, wherein the output end of the operational amplifier tube is used to output a first voltage; A first current converter has an input terminal, an output terminal, and a control terminal, wherein the input terminal of the first current converter is coupled to a first power supply, and the output terminal of the first current converter is coupled to the power supply terminal of the operational amplifier; A first digital potentiometer having a first terminal, a second terminal and a third terminal, wherein the first terminal of the first digital potentiometer receives a first control signal, and the second terminal and the third terminal of the first digital potentiometer are both coupled to the control terminal of the first current converter; The first control signal is used to adjust the resistance value of the first digital potentiometer, and the first current converter outputs a second voltage to the power supply terminal of the operational amplifier according to the resistance value input at the control terminal.

2. The operational amplifier power supply regulating circuit according to claim 1, wherein: The operational amplifier power supply regulating circuit further includes a control module, wherein the control module is coupled to the first end of the first digital potentiometer; The control module is used to output a first control signal to adjust the resistance value of the first digital potentiometer.

3. The operational amplifier power supply regulating circuit according to claim 1, wherein: The op amp power supply regulation circuit also includes a first fixed resistor, which has a first end and a second end. The first end of the first fixed resistor is coupled to the second end and the third end of the first digital potentiometer, and the second end of the first fixed resistor is coupled to the control end of the first current converter.

4. The operational amplifier power supply regulating circuit according to claim 1, wherein: The power supply terminal of the operational amplifier tube includes a positive power supply pin, and the output terminal of the first current converter is coupled to the positive power supply pin of the operational amplifier tube.

5. The operational amplifier power supply regulating circuit according to claim 1, wherein: The power supply terminal of the operational amplifier tube includes a negative power supply pin, and the output terminal of the first current converter is coupled to the negative power supply pin of the operational amplifier tube.

6. The operational amplifier power supply regulating circuit according to claim 1, wherein: The power supply terminal of the operational amplifier tube includes a positive power supply pin and a negative power supply pin, the output terminal of the first current converter is coupled to the positive power supply pin of the operational amplifier tube, and the operational amplifier power supply regulation circuit further includes: a second current converter having an input terminal, an output terminal, and a control terminal, wherein the input terminal of the second current converter is coupled to a second power supply, and the output terminal of the second current converter is coupled to a negative power supply pin of the operational amplifier; a second digital potentiometer having a first terminal, a second terminal, and a third terminal, wherein the first terminal of the second digital potentiometer receives a second control signal, and the second terminal and the third terminal of the second digital potentiometer are both coupled to the control terminal of the second current converter; The first control signal is further used to adjust the resistance value of the second digital potentiometer, and the second current converter outputs a third voltage to the negative power supply pin of the operational amplifier according to the resistance value input at the control end.

7. The operational amplifier power supply regulating circuit according to claim 6, wherein: The op amp power supply regulation circuit also includes a second fixed resistor, which has a first end and a second end. The first end of the second fixed resistor is coupled to the second end and the third end of the second digital potentiometer, and the second end of the second fixed resistor is coupled to the control end of the second current converter.

8. The operational amplifier power supply regulating circuit according to claim 6, wherein: The op amp power supply regulation circuit also includes a control module, which is coupled to the first end of the first digital potentiometer and the first end of the second digital potentiometer; the control module is used to output a first control signal to adjust the resistance value of the first digital potentiometer, and the control module is also used to output a second control signal to adjust the resistance value of the second digital potentiometer.

9. The operational amplifier power supply regulating circuit according to claim 6, wherein: The operational amplifier is configured to receive the second voltage at the positive power pin or the third voltage at the negative power pin as a power supply voltage of the operational amplifier.

10. The operational amplifier power supply regulating circuit according to claim 1, wherein: The first current converter is a DC converter.

Images