Pin protection circuit and signal protection circuit

Abstract

The invention discloses a pin protection circuit and a signal protection circuit, and belongs to the technical field of power electronics, and the pin protection circuit comprises a constant current source, a PCB used for bearing the constant current source, a signal collector which is arranged on the PCB and is powered by the constant current source, and a signal amplification module which is used for carrying out signal amplification on a collected signal of the signal collector. And each pin of the signal collector and the signal amplification module is provided with a signal ring which has the same potential as the output pin of the signal collector. Because each pin of the signal collector and the signal amplification module is provided with a signal ring having the same potential as the output pin of the signal collector, no potential difference is generated between the pins of the signal collector and the signal amplification module on the PCB. Therefore, the electric leakage phenomenon of all devices on the PCB where the constant current source is located due to the fact that the pin via holes or the distance between the pins is too small can be avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics, and particularly relates to a pin protection circuit and a signal protection circuit. Background Art

[0002] In the prior art, many precision instruments require a constant current source for power supply, and a signal amplifier is used to amplify the signals collected by the precision instruments. The current of the constant current source is usually in the microampere level and is easily interfered by other signals. If there are pin vias or the distance between pins of the devices on the PCB (Printed Circuit Board) where the constant current source is located is too small, leakage will occur, which will seriously affect the stable operation of each device on the PCB. Currently, there is no relatively effective solution to this technical problem.

[0003] Therefore, how to avoid the leakage phenomenon caused by pin vias or too small distance between pins of each device on the PCB where the constant current source is located is a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a pin protection circuit and a signal protection circuit to solve the technical problem that leakage occurs due to pin vias or too small distance between pins of each device on the PCB where the constant current source is located in the prior art. The specific solutions are as follows:

[0005] To solve the above technical problem, the present application discloses a pin protection circuit, including: a constant current source, a PCB for carrying the constant current source, a signal collector powered by the constant current source provided on the PCB, and a signal amplification module for amplifying the collected signal of the signal collector. Moreover, signal rings with the same potential as the output pin of the signal collector are provided on each pin of the signal collector and the signal amplification module.

[0006] Preferably, the signal ring is specifically a trace ring.

[0007] Preferably, the signal ring is a voltage ring generated by a first operational amplifier and a second operational amplifier;

[0008] Wherein, the first end of the signal collector is connected to the first input end of the signal amplification module through the first operational amplifier, and the second end of the signal collector is connected to the second input end of the signal amplification module through the second operational amplifier.

[0009] Preferably, it further includes:

[0010] A first filtering circuit and a second filtering circuit are used to filter the supply voltages of the first operational amplifier and the second operational amplifier respectively.

[0011] Preferably, the first operational amplifier and the second operational amplifier are both chopper operational amplifiers.

[0012] Preferably, it also includes:

[0013] A third filtering circuit is used for filtering the chopper operational amplifier.

[0014] Preferably, the third filtering circuit is specifically an RC low-pass filtering circuit.

[0015] Preferably, the signal collector is specifically a thermistor sensor or an RTD or a sampling resistor.

[0016] Preferably, the signal amplification module is specifically a differential amplifier.

[0017] In order to solve the above technical problems, the present application also discloses a signal protection circuit, including a pin protection circuit as disclosed above.

[0018] It can be seen that in the pin protection circuit provided by the present invention, a constant current source is provided, a PCB for carrying the constant current source, a signal collector powered by the constant current source and a signal amplification module for amplifying the collected signal of the signal collector are provided on the PCB, and each pin of the signal collector and the signal amplification module is provided with a signal ring having the same potential as the output pin of the signal collector. Compared with the prior art, since each pin of the signal collector and the signal amplification module is provided with a signal ring having the same potential as the output pin of the signal collector, no potential difference will be generated between the pins of the signal collector and the signal amplification module on the PCB, thereby avoiding leakage of each device on the PCB where the constant current source is located due to pin vias or too small spacing between pins. Correspondingly, a signal protection circuit provided by the present invention also has the above-mentioned beneficial effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0020] Figure 1 A structural diagram of a pin protection circuit provided by an embodiment of the present invention;

[0021] Figure 2 A structural diagram when the signal loop in the pin protection circuit is set as a routing loop provided by an embodiment of the present invention;

[0022] Figure 3 A structural diagram when the signal loop in the pin protection circuit is set as a voltage loop provided by an embodiment of the present invention;

[0023] Figure 4 Another structural diagram of the pin protection circuit provided by an embodiment of the present invention. Detailed implementation manners

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0025] Please refer to Figure 1 , Figure 1 A structural diagram of a pin protection circuit provided by an embodiment of the present invention. The pin protection circuit includes: a constant current source 11, a PCB 12 for carrying the constant current source 11, a signal collector 13 powered by the constant current source 11 provided on the PCB 12, and a signal amplification module 14 for amplifying the collected signal of the signal collector 13. Moreover, signal loops 15 having the same potential as the output pins of the signal collector 13 are provided on each pin of the signal collector 13 and the signal amplification module 14.

[0026] In this embodiment, a pin protection circuit is provided, and by using this circuit, the leakage phenomenon generated by each device on the PCB 12 where the constant current source 11 is located due to pin vias or too small spacing between pins can be avoided.

[0027] In this pin protection circuit, a constant current source 11, a PCB 12 for carrying the constant current source 11, a signal collector 13 powered by the constant current source 11, and a signal amplification module 14 are provided. Moreover, signal loops 15 having the same potential as the output pins of the signal collector 13 are provided on each pin of the signal collector 13 and the signal amplification module 14.

[0028] It should be noted that in this embodiment, Figure 1 ① and ② in the signal collector 13 represent two output pins of the signal collector 13, and ① and ② in the signal amplification module 14 represent two output pins of the signal amplification module 14.

[0029] It can be understood that the constant current source 11 is usually required to supply power to high-precision instruments, and the supply current is relatively small, generally at the microampere level. Therefore, the constant current source 11 is usually applied in a signal amplification circuit, as Figure 1 shown in the circuit application scenario.

[0030] It can be conceived that after a signal loop 15 with the same potential as the output pin of the signal collector 13 is set on each pin of the signal collector 13 and the signal amplification module 14, no potential difference will be generated between the pins of the signal collector 13 and the signal amplification module 14 on the PCB 12. Thus, the leakage phenomenon caused by the via holes of the pins or the too small distance between the pins of each device on the PCB 12 where the constant current source 11 is located can be avoided, and in this way, the pins of each device on the PCB 12 can be protected more effectively.

[0031] Specifically, in practical applications, the signal collector 13 can be set as a thermistor sensor, an RTD (Resistance Temperature Detector), or a sampling resistor. Since these devices are all relatively common signal collection devices in high-precision signal collection scenarios, when the signal collector 13 is set as a thermistor sensor, an RTD, or a sampling resistor, the universality of the pin protection circuit provided in this application in practical applications can be relatively improved.

[0032] In addition, in practical applications, the signal amplification module 14 can be set as any circuit module capable of amplifying signals, such as a differential amplification circuit, a common-emitter amplification circuit, and a common-base amplification circuit, etc., which are not specifically limited here. However, as a preferred implementation manner, the signal amplification module 14 can be set as a differential amplifier. Since the setting structure of the differential amplifier is relatively simple, when the signal amplification module 14 is set as a differential amplifier, the structural complexity of the pin protection circuit provided in this application can be reduced.

[0033] It can be seen that in the pin protection circuit provided in this embodiment, a constant current source is provided, a PCB for carrying the constant current source, a signal collector powered by the constant current source is provided on the PCB, and a signal amplification module for amplifying the collected signal of the signal collector. Moreover, signal rings having the same potential as the output pin of the signal collector are provided on each pin of the signal collector and the signal amplification module. Compared with the prior art, since signal rings having the same potential as the output pin of the signal collector are provided on each pin of the signal collector and the signal amplification module, no potential difference will be generated between the pins of the signal collector and the signal amplification module on the PCB. Thus, the leakage phenomenon caused by the via holes of the pins or the too small distance between the pins of each device on the PCB where the constant current source is located can be avoided.

[0034] Based on the above embodiment, this embodiment further illustrates and optimizes the technical solution. Please refer to Figure 2 , Figure 2 FIG. is a structural diagram when the signal ring in the pin protection circuit provided in the embodiment of the present invention is set as a trace ring. As a preferred implementation manner, the signal ring 15 is specifically a trace ring 151.

[0035] In practical applications, the signal rings 15 on each pin of the signal collector 13 and the signal amplification module 14 on the PCB 12 can be set as trace rings 151, that is, by winding traces on each pin of the signal collector 13 and the signal amplification module 14 to prevent the leakage phenomenon caused by the via holes of the pins or the too small distance between the pins of each device on the PCB 12.

[0036] It can be conceived that since the cost of the traces is relatively low, when winding traces on each pin of the signal collector 13 and the signal amplification module 14 to prevent the leakage phenomenon caused by the via holes of the pins or the too small distance between the pins of each device on the PCB 12, the design cost required for the pin protection circuit provided in this application can be further reduced.

[0037] Based on the above embodiment, this embodiment further illustrates and optimizes the technical solution. Please refer to Figure 3 , Figure 3 FIG. is a structural diagram when the signal ring in the pin protection circuit provided in the embodiment of the present invention is set as a voltage ring. As a preferred implementation manner, the signal ring 15 is a voltage ring 152 generated by the first operational amplifier 101 and the second operational amplifier 102;

[0038] Among them, the first end of the signal collector 13 is connected to the first input end of the signal amplification module 14 through the first operational amplifier 101, and the second end of the signal collector 13 is connected to the second input end of the signal amplification module 14 through the second operational amplifier 102.

[0039] In practical applications, a voltage loop 152 can be added to each pin of the signal collector 13 and the signal amplification module 14 to protect the pins of each device on the PCB 12 from leakage. For specific details, please refer to Figure 3 the circuit diagram shown.

[0040] In Figure 3 it, the first end of the signal collector 13 is connected to the first input end of the signal amplification module 14 through the first operational amplifier 101, and the second end of the signal collector 13 is connected to the second input end of the signal amplification module 14 through the second operational amplifier 102. The first operational amplifier 101 collects the voltage output by the first end of the signal collector 13, and follows to generate a voltage loop 152 that is the same as the voltage output by the first end of the signal collector 13 to protect the pin of the first end of the signal collector 13. Since the output voltage of the first end of the signal collector 13 is equal to the voltage of the first input end of the signal amplification module 14, at this time, the first operational amplifier 101 can generate a voltage loop 152 with the same voltage as the first input end of the signal amplification module 14 to protect the pin of the first input end of the signal amplification module 14.

[0041] Similarly, the second operational amplifier 102 collects the voltage output by the second end of the signal collector 13, and follows to generate a voltage loop 152 that is the same as the voltage output by the second end of the signal collector 13 to protect the pin of the second end of the signal collector 13. Since the output voltage of the second end of the signal collector 13 is equal to the voltage of the second input end of the signal amplification module 14, at this time, the second operational amplifier 102 can generate a voltage loop 152 with the same voltage as the second input end of the signal amplification module 14 to protect the pin of the second input end of the signal amplification module 14.

[0042] In addition, in practical applications, since the first operational amplifier 101 and the second operational amplifier 102 have a certain driving ability, after the first operational amplifier 101 and the second operational amplifier 102 are set between the signal collector 13 and the signal amplification module 14, not only can the common-mode interference of the ground plane be avoided, but also the electric potential carried by the pins of the adjacent devices can be absorbed, so that the pins of each device on the PCB can be better protected.

[0043] As a preferred embodiment, the above-mentioned pin protection circuit further includes:

[0044] The first filter circuit and the second filter circuit are used to filter the supply voltages of the first operational amplifier 101 and the second operational amplifier 102 respectively.

[0045] In practical applications, in order to ensure the accuracy of signal acquisition by the signal collector 13, a first filtering circuit and a second filtering circuit for filtering the power supply voltages of the first operational amplifier 101 and the second operational amplifier 102 respectively can be set in the above-mentioned pin protection circuit to filter out interference signals on the power supply voltages of the first operational amplifier 101 and the second operational amplifier 102.

[0046] As a preferred implementation, the first operational amplifier 101 and the second operational amplifier 102 are both chopper operational amplifiers.

[0047] In order to further improve the accuracy of signal acquisition by the signal collector 13, the first operational amplifier 101 and the second operational amplifier 102 can also be set as chopper operational amplifiers. Because the output signal of the chopper operational amplifier is a pulse signal, the chopper operational amplifier can achieve higher accuracy signal amplification.

[0048] Moreover, the chopper operational amplifier has a simple structure and high reliability. Therefore, when the first operational amplifier 101 and the second operational amplifier 102 are set as chopper operational amplifiers, the stability and reliability of the pin protection circuit provided in the present application during use can also be improved.

[0049] In addition, in order to filter out the noise signal at the input end of the chopper operational amplifier, a third filter circuit for filtering the chopper operational amplifier can also be provided in the above-mentioned pin protection circuit. Considering that the chopper operational amplifier in the pin protection circuit provided by the present application needs to filter out the high-frequency interference signal at the signal input end, in practical applications, the third filter can also be set as an RC (resistance-capacitance) low-pass filter.

[0050] Obviously, in this embodiment, by setting a voltage ring with the same potential as the pin voltage on each pin of the signal collector 13 and the signal amplification module 14, leakage of each device on the PCB 12 due to pin vias or too small a distance between pins can be avoided.

[0051] In order to enable those skilled in the art to more clearly understand the implementation principle of the pin protection circuit provided by the present application, the pin protection circuit provided above is described in detail through an application scenario embodiment. Figure 4 , Figure 4 This is a structural diagram of another pin protection circuit provided by an embodiment of the present invention.

[0052] exist Figure 4Among them, U1 is the first chopper operational amplifier, U2 is the second chopper operational amplifier, and U3 is the differential amplifier. When the uA-class constant current source supplies power to the sampling resistor, the voltage at pin 2 of the sampling resistor is sent to pin 5 of the first chopper operational amplifier U1 and pin 4 of the differential amplifier U3. The first chopper operational amplifier U1 will follow its pins 1 and 2 to output a large current signal to protect pin 2 of the sampling resistor and pin 4 of the differential amplifier, and prevent pin 2 of the sampling resistor and pin 4 of the differential amplifier U3 from having a leakage phenomenon.

[0053] At the same time, the voltage at pin 3 of the sampling resistor is sent to pin 5 of the second chopper operational amplifier U2 and pin 1 of the differential amplifier U3. The second chopper operational amplifier U2 will follow its pins 1 and 2 to output a large current signal to protect pin 3 of the sampling resistor and pin 1 of the differential amplifier, and prevent pin 3 of the sampling resistor and pin 1 of the differential amplifier U3 from having a leakage phenomenon.

[0054] In Figure 4 Among them, the fifth resistor R5 and the fifth capacitor C5, and the sixth resistor R6 and the sixth capacitor C6 are two groups of RC low-pass filter circuits, whose purpose is to filter out the high-frequency interference at the input ends of the first chopper operational amplifier U1 and the second chopper operational amplifier U2. The first resistor R1 and the first capacitor C1, the second resistor R2 and the second capacitor C2, the third resistor R3 and the third capacitor C3, the fourth resistor R4 and the fourth capacitor C4, the eighth resistor R8 and the seventh capacitor C7, and the ninth resistor R9 and the eighth capacitor C8 are six groups of RC low-pass filter circuits, which are respectively used for low-pass filtering of the supply voltages of the first chopper operational amplifier U1, the second chopper operational amplifier U2, and the differential amplifier U3.

[0055] Obviously, Figure 4 The pin protection circuit shown can not only prevent the leakage phenomenon of each pin on the sampling resistor and the differential amplifier due to pin vias or too small distance between pins, but also greatly reduce the noise interference in the circuit.

[0056] Correspondingly, the embodiment of the present invention also provides a signal protection circuit, including a pin protection circuit as disclosed above.

[0057] It should be noted that the signal protection circuit provided by this application is mainly applied to the scenario where weak current signals are prone to leakage phenomena due to pin vias or too small pin spacing on the PCB.

[0058] The signal protection circuit provided by the embodiment of the present invention has the beneficial effects of a pin protection circuit as disclosed above.

[0059] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other. Finally, it should be noted that in this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0060] The above has introduced in detail a pin protection circuit and a signal protection circuit provided by the present invention. Specific examples are used in this text to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A pin protection circuit, characterized in that, it includes: A constant current source, a PCB for carrying the constant current source, a signal collector powered by the constant current source provided on the PCB, and a signal amplification module for amplifying the collected signal of the signal collector. Moreover, signal rings with the same potential as the output pin of the signal collector are provided on each pin of the signal collector and the signal amplification module.

2. The pin protection circuit according to claim 1, characterized in that, The signal ring is specifically a trace ring.

3. The pin protection circuit according to claim 1, characterized in that, The signal ring is a voltage ring generated by a first operational amplifier and a second operational amplifier; wherein, the first end of the signal collector is connected to the first input end of the signal amplification module through the first operational amplifier, and the second end of the signal collector is connected to the second input end of the signal amplification module through the second operational amplifier.

4. The pin protection circuit according to claim 3, characterized in that, it further includes: A first filter circuit and a second filter circuit for filtering the supply voltages of the first operational amplifier and the second operational amplifier respectively.

5. The pin protection circuit according to claim 3, characterized in that, Both the first operational amplifier and the second operational amplifier are chopper operational amplifiers.

6. The pin protection circuit according to claim 5, characterized in that, it further includes: A third filter circuit for filtering the chopper operational amplifier.

7. The pin protection circuit according to claim 6, characterized in that, The third filter circuit is specifically an RC low-pass filter circuit.

8. The pin protection circuit according to claim 1, characterized in that, The signal collector is specifically a thermistor sensor or an RTD or a sampling resistor.

9. The pin protection circuit according to claim 1, characterized in that, The signal amplification module is specifically a differential amplifier.

10. A signal protection circuit, characterized in that, it includes a pin protection circuit according to any one of claims 1 to 9.

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