Ultra-low noise industrial adaptive operational amplifier

Abstract

The ultra-low noise industrial adaptive operational amplifier comprises an operational amplifier circuit, the input end of the operational amplifier circuit is electrically connected with an input end protection circuit, and the output end of the operational amplifier circuit is electrically connected with an overcurrent protection circuit; the operational amplifier circuit comprises a buffer operational amplifier AD1, a buffer operational amplifier AD2 and a secondary operational amplifier AD3. A pin 2 of the buffer operational amplifier AD1 is electrically connected with one end of a resistor R6 and one end of a resistor R4. Through the arrangement of the operational amplifier circuit, the input end protection circuit and the overcurrent protection circuit, noise reduction can be effectively carried out on the circuit, the effect of effectively reducing noise is achieved, voltage in the circuit can be protected, current can be monitored in real time, power can be cut off in time when the current is large, and the service life of the circuit is prolonged. And the risk of damage to industrial equipment caused by large current is effectively reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of operational amplifiers, in particular to an ultra-low noise industrial adaptation operational amplifier. Background Art

[0002] An operational amplifier is a circuit unit with a very high amplification factor. In actual circuits, it is usually combined with a feedback network to form a functional module. It is an amplifier with a special coupling circuit and feedback. Its output signal can be the result of mathematical operations such as addition, subtraction, differentiation, and integration of the input signal. In some special application systems, there are high requirements for the noise of operational amplifiers, and low-noise technology is particularly important. The noise reduction and circuit protection effects of operational amplifiers in current technology are not ideal. During use, high noise and excessive current and voltage will affect the operation of the equipment. When the current is large, it is easy to cause damage to the equipment and cannot meet the use requirements. Based on the above situation, we propose an ultra-low noise industrial adaptation operational amplifier. Utility Model Content

[0003] The utility model aims to solve the shortcomings in the prior art and proposes an ultra-low noise industrial adaptation operational amplifier.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] An ultra-low noise industrial adaptation operational amplifier comprises an operational amplifier circuit, wherein an input end of the operational amplifier circuit is electrically connected to an input end protection circuit, and an output end of the operational amplifier circuit is electrically connected to an overcurrent protection circuit;

[0006] The operational amplifier circuit includes a buffer operational amplifier AD1, a buffer operational amplifier AD2, and a secondary operational amplifier AD3. Pin 2 of the buffer operational amplifier AD1 is electrically connected to one end of a resistor R6 and one end of a resistor R4. The other end of the resistor R6 is electrically connected to pin 1 of the buffer operational amplifier AD2. Pin 3 of the buffer operational amplifier AD1 is electrically connected to the other end of the resistor R4. Pin 3 of the buffer operational amplifier AD2 is electrically connected to one end of a resistor R5. The other end of the resistor R5 is electrically connected to pin 1 of the buffer operational amplifier AD2. Pin 1 of the secondary operational amplifier AD3 is electrically connected to resistor R6. 2, the other end of the resistor R2 is electrically connected to pin 3 of the buffer operational amplifier AD1, pin 1 of the secondary operational amplifier AD3 is electrically connected to one end of the resistor R1, the other end of the resistor R1 is electrically connected to pin 3 of the secondary operational amplifier AD3, both ends of the resistor R1 are connected in parallel with a voltage regulator tube S, pin 2 of the secondary operational amplifier AD3 is electrically connected to one end of the resistor R11, the other end of the resistor R11 is electrically connected to a reference current, pin 2 of the secondary operational amplifier AD3 is electrically connected to one end of the resistor R3, and the other end of the resistor R3 is electrically connected to pin 3 of the buffer operational amplifier AD2 and one end of the resistor R5.

[0007] Preferably, the input protection circuit includes a diode D1, pin 1 and pin 2 of the buffer operational amplifier AD1 are electrically connected to the diode D1, the two ends of the diode D1 are connected in parallel with the same diode D2, the positive pole of the diode D2 is electrically connected to one end of the resistor R7, and the negative pole of the diode D2 is electrically connected to one end of the resistor R8, the pin 1 and pin 2 of the buffer operational amplifier AD2 are electrically connected to the same diode D3, the two ends of the diode D3 are connected in parallel with the same diode D4, the positive pole of the diode D4 is electrically connected to one end of the resistor R10, and the negative pole of the diode D4 is electrically connected to one end of the resistor R9.

[0008] Preferably, the overcurrent protection circuit includes a resistor R12, one end of the resistor R12 is electrically connected to pin 3 of the secondary operational amplifier AD3, pin 2 of the secondary operational amplifier AD3 is electrically connected to one end of the resistor R13, the other end of the resistor R13 is electrically connected to the other end of the resistor R12, the other end of the resistor R12 and the other end of the resistor R13 are electrically connected to one end of the same MOSFET IRF tube, the other end of the MOSFET IRF tube is electrically connected to one end of the resistor R14, and the other end of the resistor R14 and the shunt end of the MOSFET IRF tube are both grounded.

[0009] Preferably, the MOSFET IRF tube is used to control the load to be ON or OFF under normal and overload conditions.

[0010] Preferably, the voltage regulator tube S is used to stabilize the output end of the operational amplifier circuit.

[0011] Compared with the existing technology, the beneficial effects of the utility model are:

[0012] 1. The operational amplifier circuit can be used to reduce the noise generated, achieving the effect of low noise output;

[0013] 2. By setting up the input protection circuit and the overcurrent protection circuit, the voltage in the circuit can be protected to achieve the effect of voltage regulation output, and the current in the circuit can be detected. When overcurrent occurs, the power can be cut off in time, which can effectively reduce the risk of damage to industrial equipment caused by large current input to subsequent circuits.

[0014] The utility model can effectively reduce the noise of the circuit through the arrangement of the operational amplifier circuit, the input protection circuit and the overcurrent protection circuit, thereby achieving an effective noise reduction effect, and can protect the voltage in the circuit and monitor the current in real time, and can cut off the power in time when the current is large, effectively reducing the risk of damage to industrial equipment caused by the large current. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A circuit diagram of an ultra-low noise industrial adaptation operational amplifier proposed by the utility model;

[0016] Figure 2 The utility model discloses a circuit diagram of an overcurrent protection circuit of an ultra-low noise industrial adaptation operational amplifier and a secondary operational amplifier AD3 connected thereto. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0018] Reference Figure 1-2 , an ultra-low noise industrial adaptation operational amplifier, comprising an operational amplifier circuit, an input end of the operational amplifier circuit being electrically connected to an input end protection circuit, and an output end of the operational amplifier circuit being electrically connected to an overcurrent protection circuit;

[0019] The operational amplifier circuit includes a buffer operational amplifier AD1, a buffer operational amplifier AD2, and a secondary operational amplifier AD3. Pin 2 of the buffer operational amplifier AD1 is electrically connected to one end of a resistor R6 and one end of a resistor R4. The other end of the resistor R6 is electrically connected to pin 1 of the buffer operational amplifier AD2. Pin 3 of the buffer operational amplifier AD1 is electrically connected to the other end of the resistor R4. Pin 3 of the buffer operational amplifier AD2 is electrically connected to one end of a resistor R5. The other end of the resistor R5 is electrically connected to pin 1 of the buffer operational amplifier AD2. Pin 1 of the secondary operational amplifier AD3 is electrically connected to one end of a resistor R2. The other end of the resistor R2 is electrically connected to pin 1 of the buffer operational amplifier AD2. Pin 3 of the buffer operational amplifier AD1 is electrically connected, pin 1 of the secondary operational amplifier AD3 is electrically connected to one end of the resistor R1, the other end of the resistor R1 is electrically connected to pin 3 of the secondary operational amplifier AD3, two ends of the resistor R1 are connected in parallel with a voltage regulator S, wherein the voltage regulator S is used to stabilize the output end of the operational amplifier circuit, pin 2 of the secondary operational amplifier AD3 is electrically connected to one end of the resistor R11, the other end of the resistor R11 is electrically connected to a reference current, pin 2 of the secondary operational amplifier AD3 is electrically connected to one end of the resistor R3, the other end of the resistor R3 is electrically connected to pin 3 of the buffer operational amplifier AD2 and one end of the resistor R5;

[0020] The input protection circuit includes a diode D1, pin 1 and pin 2 of the buffer operational amplifier AD1 are electrically connected to the diode D1, the two ends of the diode D1 are connected in parallel with the same diode D2, the anode of the diode D2 is electrically connected to one end of the resistor R7, the cathode of the diode D2 is electrically connected to one end of the resistor R8, the pin 1 and pin 2 of the buffer operational amplifier AD2 are electrically connected to the same diode D3, the two ends of the diode D3 are connected in parallel with the same diode D4, the anode of the diode D4 is electrically connected to one end of the resistor R10, and the cathode of the diode D4 is electrically connected to one end of the resistor R9;

[0021] The overcurrent protection circuit includes a resistor R12, one end of the resistor R12 is electrically connected to pin 3 of the secondary operational amplifier AD3, pin 2 of the secondary operational amplifier AD3 is electrically connected to one end of the resistor R13, the other end of the resistor R13 is electrically connected to the other end of the resistor R12, the other end of the resistor R12 and the other end of the resistor R13 are electrically connected to one end of the same MOSFET IRF tube, wherein the MOSFET IRF tube is used to control the load to be ON or OFF under normal and overload conditions, the other end of the MOSFET IRF tube is electrically connected to one end of the resistor R14, and the other end of the resistor R14 and the shunt end of the MOSFET IRF tube are both grounded; the utility model can effectively reduce the noise of the circuit through the setting of the operational amplifier circuit, the input protection circuit and the overcurrent protection circuit, thereby achieving an effective noise reduction effect, and can protect the voltage in the circuit and monitor the current in real time, and can cut off the power in time when the current is large, effectively reducing the risk of damage to industrial equipment caused by large current.

[0022] Working principle: When in use, the input buffer gain in the circuit is increased by setting the buffer operational amplifier AD1 and the buffer operational amplifier AD2, and the power rail is reduced. At the same time, with the setting of the secondary operational amplifier AD3, as much gain as possible can be moved to the buffer, and the lowest noise can be provided, thereby achieving an effective noise reduction effect, which meets the application requirements of industrial equipment. In addition, with the input protection circuit set at the input end of the operational amplifier circuit, the input voltage can be protected to reduce the voltage loss, and the protected voltage is input to the operational amplifier circuit for amplification. At the same time, with the output of the voltage regulator tube S, the output voltage is a stable voltage, and the overcurrent protection circuit is set. During the conduction state of the MOSFET IRF tube, the load current flows from the drain of the MOSFET IRF tube to the source, and finally flows to the ground wire GND through the shunt resistor. According to the load current, the voltage drop generated by the shunt resistor can be calculated using Ohm's law, thereby achieving the purpose of detecting the load current, and the power can be cut off in time when the current is large, which can effectively reduce the risk of damage to industrial equipment caused by large current input to subsequent circuits.

[0023] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An ultra-low noise industrial-adaptive operational amplifier, comprising an operational amplifier circuit, characterized in that: The input end of the operational amplifier circuit is electrically connected to an input end protection circuit, and the output end of the operational amplifier circuit is electrically connected to an overcurrent protection circuit; The operational amplifier circuit includes a buffer operational amplifier AD1, a buffer operational amplifier AD2, and a secondary operational amplifier AD3. Pin 2 of the buffer operational amplifier AD1 is electrically connected to one end of a resistor R6 and one end of a resistor R4. The other end of the resistor R6 is electrically connected to pin 1 of the buffer operational amplifier AD2. Pin 3 of the buffer operational amplifier AD1 is electrically connected to the other end of the resistor R4. Pin 3 of the buffer operational amplifier AD2 is electrically connected to one end of a resistor R5. The other end of the resistor R5 is electrically connected to pin 1 of the buffer operational amplifier AD2. Pin 2 of the secondary operational amplifier AD3 is electrically connected to one end of a resistor R6 and one end of a resistor R4. 1 is electrically connected to one end of a resistor R2, the other end of the resistor R2 is electrically connected to pin 3 of the buffer operational amplifier AD1, pin 1 of the secondary operational amplifier AD3 is electrically connected to one end of the resistor R1, the other end of the resistor R1 is electrically connected to pin 3 of the secondary operational amplifier AD3, a voltage regulator tube S is connected in parallel across both ends of the resistor R1, pin 2 of the secondary operational amplifier AD3 is electrically connected to one end of a resistor R11, pin 2 of the secondary operational amplifier AD3 is electrically connected to one end of a resistor R3, and the other end of the resistor R3 is electrically connected to pin 3 of the buffer operational amplifier AD2 and one end of a resistor R5.

2. The ultra-low noise industrial adapted operational amplifier according to claim 1, characterized in that: The input end protection circuit includes a diode D1, pin 1 and pin 2 of the buffer operational amplifier AD1 are electrically connected to the diode D1, the two ends of the diode D1 are connected in parallel with the same diode D2, the positive electrode of the diode D2 is electrically connected to one end of the resistor R7, and the negative electrode of the diode D2 is electrically connected to one end of the resistor R8, the pin 1 and pin 2 of the buffer operational amplifier AD2 are electrically connected to the same diode D3, the two ends of the diode D3 are connected in parallel with the same diode D4, the positive electrode of the diode D4 is electrically connected to one end of the resistor R10, and the negative electrode of the diode D4 is electrically connected to one end of the resistor R9.

3. The ultra-low noise industrial adapted operational amplifier according to claim 1, characterized in that: The overcurrent protection circuit includes a resistor R12, one end of the resistor R12 is electrically connected to pin 3 of the secondary operational amplifier AD3, pin 2 of the secondary operational amplifier AD3 is electrically connected to one end of the resistor R13, the other end of the resistor R13 is electrically connected to the other end of the resistor R12, the other end of the resistor R12 and the other end of the resistor R13 are electrically connected to one end of the same MOSFET IRF tube, the other end of the MOSFET IRF tube is electrically connected to one end of the resistor R14, and the other end of the resistor R14 and the shunt end of the MOSFET IRF tube are both grounded.

4. The ultra-low noise industrial adapted operational amplifier according to claim 3, characterized in that: The MOSFET IRF tube is used to control the load to be ON or OFF under normal and overload conditions.

5. The ultra-low noise industrial adapted operational amplifier according to claim 1, characterized in that: The voltage regulator tube S is used to stabilize the output end of the operational amplifier circuit.

6. The ultra-low noise industrial adapted operational amplifier according to claim 1, characterized in that: The other end of the resistor R11 is electrically connected to a reference current.

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