Current sampling circuit and electronic equipment

Abstract

The utility model discloses a current sampling circuit and electronic equipment. The current sampling circuit comprises a current collector, a voltage follower, a differential amplifier and a processor. Wherein the current collector is connected with a to-be-detected current source and is used for collecting a current signal of the to-be-detected current source and generating a voltage signal according to the current signal; the voltage follower is connected with the current collector and is used for filtering the voltage signal; the differential amplifier is connected with the voltage follower and used for generating a differential amplification signal according to the filtered voltage signal, and the processor is used for generating a current sampling signal according to the differential amplification signal. The current sampling circuit can play an isolation role through the arrangement of the voltage follower, the stability of signals is improved, the differential amplifier can reduce the influence of common-mode noise and electromagnetic interference on signal transmission, the anti-interference capability of the signals in the long-distance transmission process is improved, and therefore the signal transmission efficiency is improved. And the accuracy of the current sampling signal generated by the processor is improved.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to a current sampling circuit and electronic equipment. Background Art

[0002] As global electricity demand continues to rise, current sampling plays an increasingly critical role in power transmission, electronic equipment, and industrial control. By precisely monitoring and regulating circuit conditions, it ensures the stability, safety, and efficiency of power applications. In related technologies, current sampling modules sample current signals and convert them into voltage signals. Over long distances, the sampled signals are susceptible to interference from the external electromagnetic environment. Direct transmission to subsequent control circuits can easily cause signal distortion, affecting signal transmission accuracy and stability. Utility Model Content

[0003] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application needs to provide a current sampling circuit and an electronic device.

[0004] The current sampling circuit of the embodiment of the present application includes:

[0005] a current collector, connected to the current source to be measured, for collecting the current signal of the current source to be measured and generating a voltage signal according to the current signal;

[0006] a voltage follower, connected to the current collector, for filtering the voltage signal; and

[0007] A differential amplifier is connected to the voltage follower and is used to generate a differential amplified signal according to the filtered voltage signal.

[0008] In some embodiments, the current collector comprises:

[0009] A Hall sensor, the Hall sensor comprising two input terminals and two output terminals, each of the input terminals being respectively connected to the current source to be measured to collect the current signal, and each of the output terminals outputting a voltage signal;

[0010] When the current sampling circuit includes two voltage followers, each voltage follower is connected to one output terminal.

[0011] In some embodiments, the voltage follower includes:

[0012] A filter unit, one end of which is connected to the current collector and is used to filter out interference signals;

[0013] A first amplifier, wherein a first input end of the first amplifier is connected to an output end of the first amplifier, a second input end of the first amplifier is connected to the other end of the filtering unit, and an output end of the first amplifier is connected to the differential amplifier.

[0014] In some embodiments, the filtering unit includes:

[0015] a first resistor, one end of the first resistor being connected to the output end of the Hall sensor, and the other end of the first resistor being connected to the second input end of the first amplifier;

[0016] A first capacitor, one end of the first capacitor is connected to the other end of the first resistor, and the other end of the first capacitor is connected to the ground.

[0017] In some embodiments, the differential amplifier includes:

[0018] a second resistor, one end of which is connected to one of the voltage followers;

[0019] a third resistor, one end of which is connected to the reference voltage terminal;

[0020] a fourth resistor, one end of which is connected to another voltage follower;

[0021] a second amplifier, wherein a first input end of the second amplifier is connected to the other end of the second resistor and the other end of the third resistor, a second input end of the second amplifier is connected to the other end of the fourth resistor, and an output end of the second amplifier is connected to the processor;

[0022] a fifth resistor, one end of which is connected to the second input end of the second amplifier, and the other end of which is connected to the output end of the second amplifier;

[0023] a second capacitor, one end of which is connected to the reference voltage terminal, and the other end of which is connected to the first input terminal of the second amplifier;

[0024] A third capacitor has one end connected to the second input end of the second amplifier and the other end connected to the output end of the second amplifier.

[0025] In some embodiments, the differential amplifier further comprises:

[0026] a sixth resistor, one end of which is connected to the output end of the second amplifier, and the other end of which is connected to the processor;

[0027] A fourth capacitor has one end connected to one end of the sixth resistor and the other end connected to the ground.

[0028] An electronic device according to an embodiment of the present application includes the current sampling circuit according to any one of the above embodiments.

[0029] In the current sampling circuit and electronic device of the embodiments of the present application, through the setting of the voltage follower and the differential amplifier, the voltage follower can play an isolation role and improve the stability of the signal, while the differential amplifier can reduce the impact of common-mode noise and electromagnetic interference on signal transmission, thereby improving the anti-interference ability of the signal during long-distance transmission, thereby avoiding signal distortion during long-distance transmission and improving the accuracy of the current sampling signal.

[0030] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0032] Figure 1 It is a module schematic diagram of the current sampling circuit according to the embodiment of the present application.

[0033] Figure 2 4 is a circuit diagram of a current sampling circuit according to an embodiment of the present application.

[0034] Figure 3 This is a schematic diagram of actual measurement of the current sampling circuit according to the embodiment of the present application.

[0035] Description of main component symbols:

[0036] 10-current sampling circuit, 12-current collector, 121-Hall sensor, 14-voltage follower, 141-filter unit, R1-first resistor, C1-first capacitor, 142-first amplifier, 16-differential amplifier, R2-second resistor, R3-third resistor, R4-fourth resistor, R5-fifth resistor, R6-sixth resistor, C2-second capacitor, C3-third capacitor, C4-fourth capacitor, 162-second amplifier, 18-processor, Vref-reference voltage terminal, GND-ground terminal. DETAILED DESCRIPTION

[0037] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be understood as limiting the present application.

[0038] See also Figure 1 and Figure 2The present application provides a current sampling circuit 10, which includes a current collector 12, a voltage follower 14, a differential amplifier 16, and a processor 18. The current collector 12 is connected to a current source to be measured, and is configured to collect a current signal from the current source to be measured and generate a voltage signal based on the current signal; the voltage follower 14 is connected to the current collector 12, and is configured to filter the voltage signal; the differential amplifier 16 is connected to the voltage follower 14, and is configured to generate a differential amplified signal based on the filtered voltage signal; and the processor 18 is configured to generate a current sampling signal based on the differential amplified signal.

[0039] In the current sampling circuit 10 of the embodiment of the present application, through the setting of the voltage follower 14 and the differential amplifier 16, the voltage follower 14 can play an isolation role and improve the stability of the signal, while the differential amplifier 16 can reduce the impact of common-mode noise and electromagnetic interference on signal transmission, thereby improving the anti-interference ability of the signal during long-distance transmission, and can effectively reduce the interference of the external electromagnetic environment, ensuring the integrity, accuracy and efficiency of the signal transmission process. In this way, signal distortion during long-distance transmission is avoided, and the accuracy and stability of the current sampling signal generated by the processor 18 are guaranteed.

[0040] Specifically, current collector 12 operates on the principle of magnetic field induction. When current flows through a conductor, it generates a magnetic field around it, the strength of which is proportional to the magnitude of the current. Using this principle, current collector 12 converts the current signal from the current source under test into a voltage signal for subsequent digital circuit processing. In electronic devices, current collector 12 can be used to monitor the current flow of the device to ensure its stability and safety.

[0041] Voltage follower 14 is an electronic component that achieves output voltage tracking changes in input voltage. In other words, the voltage amplification factor of voltage follower 14 is always less than and close to 1. Voltage follower 14 has the characteristics of high input impedance, low output impedance, an output voltage nearly equal to the input voltage, and high linearity, providing isolation and buffering. Therefore, in the embodiments of the present application, voltage follower 14 serves as a buffer in the signal transmission of current sampling circuit 10, preventing the subsequent circuit from affecting the previous circuit, thereby ensuring accurate signal transmission.

[0042] Differential amplifier 16 offers advantages such as high precision, low noise, strong anti-interference capabilities, and low power consumption. Therefore, the inclusion of differential amplifier 16 in current sampling circuit 10 effectively suppresses noise within the circuit and improves the signal's resistance to electromagnetic interference. Differential amplifier 16 is connected to the output of voltage follower 14 and is used to differentially amplify the voltage signal transmitted by voltage follower 14 to generate a differential amplified signal.

[0043] Processor 18 is connected to the output of differential amplifier 16 and can be used to perform analog-to-digital conversion on the differential amplified signal to generate a current sampling signal. In this way, current sampling of the current source to be measured is achieved and the accuracy of current sampling is guaranteed. In some examples, processor 18 can be a central processing unit (CPU).

[0044] See also Figure 2 In some embodiments, the current collector 12 includes a Hall sensor 121, the Hall sensor 121 includes two input terminals and two output terminals, each input terminal is connected to a current source to be measured to collect a current signal, each output terminal outputs a voltage signal, and the voltage follower 14 includes two, each voltage follower 14 is connected to an output terminal.

[0045] See also Figure 3 In one example, the sampling current of the current source to be measured is 50A. The current source to be measured outputs a voltage value of 2.303V when passing through the current sampling circuit 10 through the Hall sensor 121 with a sampling ratio of 16mV / A. Figure 3 It can be seen that the measured value and the theoretical value are very similar, thus the current sampling circuit 10 of the embodiment of the present application has high sampling accuracy. In addition, the waveform in the figure shows that the measured current sampling signal is relatively smooth, thus the current sampling circuit 10 of the present application has good sampling stability.

[0046] See also Figure 2 In some embodiments, the voltage follower 14 includes a filter unit 141 and a first amplifier 142. One end of the filter unit 141 is connected to the current collector 12 to filter out interference signals from the voltage signal. A first input end of the first amplifier 142 is connected to the output end of the first amplifier 142. A second input end of the first amplifier 142 is connected to the filter unit 141. The output end of the first amplifier 142 is connected to the differential amplifier 16.

[0047] Among them, the filtering unit 141 can be an RC low-pass filter (RC Low-pass Filter), which is used to filter out high-frequency interference signals in the voltage signal and only allow low-frequency signals to pass. It can be understood that the RC low-pass filter can effectively eliminate the high-frequency components in the signal, so that the output signal is closer to the low-frequency part of the original signal. The output end of the first amplifier 142 outputs a voltage value with the same voltage amplitude as the input end, and is used to output the voltage signal filtered by the filtering unit 141 to the differential amplifier 16. The first input end of the first amplifier 142 can be a positive input end, and the second input end can be a negative input end.

[0048] In this way, the voltage follower 14 can filter out high-frequency interference signals of the voltage signal through the configuration of the filtering unit 141 and the first amplifier 142 , thereby isolating the transmitted voltage signal.

[0049] In some embodiments, the filtering unit 141 includes a first resistor R1 and a first capacitor C1, one end of the first resistor R1 is connected to the output end of the Hall sensor 121; one end of the first capacitor C1 is connected to the other end of the first resistor R1, and the other end of the first capacitor C1 is connected to the ground end GND.

[0050] In this way, the first resistor R1 and the first capacitor C1 can communicate with each other to form an RC low-pass filter, thereby filtering out high-frequency interference signals in the voltage signal.

[0051] Please refer to the Figure 2 In some embodiments, the differential amplifier 16 includes a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a second amplifier 162, a second capacitor C2, and a third capacitor C3. One end of the second resistor R2 is connected to one of the voltage followers 14; one end of the third resistor R3 is connected to the reference voltage terminal Vref; one end of the fourth resistor R4 is connected to the other voltage follower 14; a first input end of the second amplifier 162 is connected to the other end of the second resistor R2 and the other end of the third resistor R3; a second end of the second amplifier 162 is connected to the other end of the fourth resistor R4; and an output end of the second amplifier 162 is connected to the processor 18. One end of the fifth resistor R5 is connected to the second input end of the second amplifier 162, and the other end of the fifth resistor R5 is connected to the output end of the second amplifier 162. One end of the second capacitor C2 is connected to the reference voltage terminal Vref, and the other end of the second capacitor C2 is connected to the first input end of the second amplifier 162. One end of the third capacitor C3 is connected to the second input end of the second amplifier 162, and the other end of the third capacitor C3 is connected to the output end of the second amplifier 162.

[0052] It should be noted that the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5, and the second amplifier 162 jointly perform a proportional operation, thereby outputting a differential amplified signal (a differentially amplified voltage signal) suitable for processing by the processor 18. The second capacitor C2 and the third capacitor C3 are used to suppress high-frequency signals. The reference voltage terminal Vref is used to output a reference voltage.

[0053] In some embodiments, the differential amplifier 16 further includes a sixth resistor R6 and a fourth capacitor C4. One end of the sixth resistor R6 is connected to the output of the second amplifier 162, and the other end is connected to the processor 18. One end of the fourth capacitor C4 is connected to one end of the sixth resistor R6, and the other end of the fourth capacitor C4 is connected to the ground terminal GND.

[0054] It should be noted that the sixth resistor R6 and the fourth capacitor C4 form an RC low-pass filter for filtering out high-frequency signals.

[0055] The electronic device according to the embodiment of the present application includes the current sampling circuit 10 according to any one of the above embodiments.

[0056] In the electronic device of the embodiment of the present application, through the setting of the voltage follower 14 and the differential amplifier 16, the voltage follower 14 can play an isolation role and improve the stability of the signal, while the differential amplifier 16 can reduce the impact of common-mode noise and electromagnetic interference on signal transmission, and improve the anti-interference ability of the signal during long-distance transmission, thereby avoiding signal distortion during long-distance transmission and improving the accuracy of the current sampling signal.

[0057] Throughout this specification, reference to terms such as "one embodiment," "certain embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0058] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A current sampling circuit, characterized in that , the current sampling circuit includes: a current collector, connected to the current source to be measured, for collecting the current signal of the current source to be measured and generating a voltage signal according to the current signal; a voltage follower connected to the current collector and configured to filter the voltage signal; a differential amplifier connected to the voltage follower and configured to generate a differential amplified signal according to the filtered voltage signal; and A processor is connected to the differential amplifier and is used to generate a current sampling signal according to the differential amplified signal.

2. The current sampling circuit according to claim 1, characterized in that: The current collector comprises: A Hall sensor, the Hall sensor comprising two input terminals and two output terminals, each of the input terminals being respectively connected to the current source to be measured to collect the current signal, and each of the output terminals outputting a voltage signal; When the current sampling circuit includes two voltage followers, each voltage follower is connected to one output terminal.

3. The current sampling circuit according to claim 2, characterized in that: The voltage follower comprises: A filter unit, one end of which is connected to the current collector and is used to filter out interference signals; A first amplifier, wherein a first input end of the first amplifier is connected to an output end of the first amplifier, a second input end of the first amplifier is connected to the other end of the filtering unit, and an output end of the first amplifier is connected to the differential amplifier.

4. The current sampling circuit according to claim 3, characterized in that: The filtering unit comprises: a first resistor, one end of the first resistor being connected to the output end of the Hall sensor, and the other end of the first resistor being connected to the second input end of the first amplifier; A first capacitor, one end of the first capacitor is connected to the other end of the first resistor, and the other end of the first capacitor is connected to the ground.

5. The current sampling circuit according to claim 2, characterized in that: The differential amplifier comprises: a second resistor, one end of which is connected to one of the voltage followers; a third resistor, one end of which is connected to the reference voltage terminal; a fourth resistor, one end of which is connected to another voltage follower; a second amplifier, wherein a first input end of the second amplifier is connected to the other end of the second resistor and the other end of the third resistor, a second input end of the second amplifier is connected to the other end of the fourth resistor, and an output end of the second amplifier is connected to the processor; a fifth resistor, one end of which is connected to the second input end of the second amplifier, and the other end of which is connected to the output end of the second amplifier; a second capacitor, one end of which is connected to the reference voltage terminal, and the other end of which is connected to the first input terminal of the second amplifier; A third capacitor has one end connected to the second input end of the second amplifier and the other end connected to the output end of the second amplifier.

6. The current sampling circuit according to claim 5, characterized in that: The differential amplifier further comprises: a sixth resistor, one end of which is connected to the output end of the second amplifier, and the other end of which is connected to the processor; A fourth capacitor has one end connected to one end of the sixth resistor and the other end connected to the ground.

7. An electronic device, characterized in that: The electronic device comprises the current sampling circuit according to any one of claims 1 to 6.

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