Current detection module, bias current detection method, sampling current calibration method and intelligent device

Abstract

This invention provides a current detection module, a bias current detection method, a sampling current calibration method, and a smart device. The current detection module includes: a current detection circuit; a sampling resistor, the first end of which is connected to the first detection terminal of the current detection circuit and used to connect to the circuit under test, and the second end of which is connected to the second detection terminal of the current detection circuit and used to connect to the circuit under test; and a current detection circuit for detecting the sampling current value flowing through the sampling resistor and outputting a detected current value based on the sampling current value and a preset bias current value. This invention, by presetting a bias current value within the current detection circuit, calibrates the sampling current value using the bias current value when it is detected, eliminating errors within components such as the sampling resistor and the current detection circuit. This effectively improves the accuracy of current detection, as the accuracy of the detected current value is no longer limited by the initial accuracy of the sampling resistor.

Description

Technical Field

[0001] This invention relates to the field of electronic technology, and in particular to a current detection module, a bias current detection method, a sampling current calibration method, and an intelligent device. Background Technology

[0002] Wearable smart devices are developing rapidly, with devices like headphones and VR devices constantly iterating. During operation, it's necessary to detect the charging and discharging currents within these devices to ensure proper functioning. In current sampling scenarios, especially those with low sampling currents (milliamperes) and high sampling resistor accuracy requirements, external sampling resistors are typically used. However, due to limitations in resistor accuracy, it's difficult to further improve current detection accuracy beyond the current detection accuracy of 1%. Furthermore, product consistency is constrained by the sampling resistor and manufacturing process limitations, making it difficult to achieve the same current sampling accuracy as resistors, further reducing the overall current sampling precision.

[0003] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0004] The main objective of this invention is to provide a current detection module, a bias current detection method, a sampling current calibration method, and an intelligent device, aiming to solve the technical problem of low current sampling accuracy in existing intelligent devices.

[0005] To achieve the above objectives, the present invention proposes a current detection module, comprising: A sampling resistor, wherein the first end of the sampling resistor is connected to the first detection terminal of the current detection circuit and is used to connect to the circuit to be tested; and the second end of the sampling resistor is connected to the second detection terminal of the current detection circuit and is used to connect to the circuit to be tested. The current detection circuit is used to detect the sampling current value flowing through the sampling resistor, and output the detection current value according to the sampling current value and the preset bias current value.

[0006] Optionally, the current detection circuit includes: a current detection chip with a storage circuit; a first detection terminal of the current detection chip is connected to a first terminal of the sampling resistor, a second detection terminal of the current detection chip is connected to a second terminal of the sampling resistor, and an input terminal of the current detection chip is connected to the storage circuit; The bias current value is stored in the storage circuit.

[0007] Optionally, the current detection circuit includes: an operational amplifier circuit and a storage circuit; the first input terminal of the operational amplifier circuit is connected to the first terminal of the sampling resistor, the second input terminal of the operational amplifier circuit is connected to the second terminal of the sampling resistor, and the bias terminal of the operational amplifier circuit is connected to the storage circuit. The bias current value is stored in the storage circuit.

[0008] Optionally, the current detection module further includes: The current detection circuit and the sampling resistor are disposed inside the package housing; The encapsulation housing is provided with a first sampling interface and a second sampling interface; The first sampling interface is connected to the first terminal of the sampling resistor, and the second sampling interface is connected to the second terminal of the sampling resistor; The first sampling interface and the second sampling interface are connected to the circuit to be tested.

[0009] Optionally, the encapsulation housing is also provided with a power supply interface; The power supply interface is connected to the power supply terminal of the current detection circuit and is also used to connect to an external power source.

[0010] In addition, to achieve the above objectives, this application also provides a bias current detection method, which is applied to a current calibration device, and the current calibration device is connected to the current detection module described in any of the above claims. The bias current detection method includes: Obtain at least two actual input current values ​​that are input to the sampling resistor within the current detection module; Obtain the sampled current value output by the current detection module corresponding to each of the actual input current values; The bias current value is determined based on the actual input current value and the sampled current value.

[0011] Optionally, determining the bias current value based on the actual input current value and the sampled current value includes: The current gain value of the current detection circuit is determined based on the actual input current value and the sampled current value. The bias current value is determined based on the current gain value, the sampled current value, and the actual input current value.

[0012] Optionally, determining the current gain value of the current detection circuit based on the actual input current value and the sampled current value includes: Obtain the average current value of each sampled current value corresponding to each actual input current value; The current gain value of the current detection circuit is determined based on the average current value and the corresponding actual input current value.

[0013] Furthermore, to achieve the above objectives, the present invention also provides a sampling current calibration method, applied to the current detection circuit within the current detection module described in any of the above claims, the sampling current calibration method comprising: The sampling current value is obtained by detecting the sampling current flowing through the sampling resistor; The sampled current value is calibrated according to a preset bias current value to obtain a detected current value, wherein the bias current value is obtained by any of the above bias current detection methods.

[0014] In addition, to achieve the above objectives, the present invention also provides a smart device comprising: a device body and a current detection module as described in any one of the above claims, wherein the current detection module is connected to the circuit to be detected within the device body.

[0015] This invention provides a current detection module, a bias current detection method, a sampling current calibration method, and a smart device. The current detection module includes: a current detection circuit; a sampling resistor, wherein a first end of the sampling resistor is connected to a first detection terminal of the current detection circuit and is used to connect to a circuit under test, and a second end of the sampling resistor is connected to a second detection terminal of the current detection circuit and is used to connect to the circuit under test; the current detection circuit is used to detect the sampling current value flowing through the sampling resistor and output a detected current value based on the sampling current value and a preset bias current value. This invention, by presetting a bias current value within the current detection circuit, calibrates the sampling current value using the bias current value when the sampling current value is detected, eliminating errors within components such as the sampling resistor and the current detection circuit. This effectively improves the accuracy of current detection, as the accuracy of the detected current value is no longer limited by the initial accuracy of the sampling resistor. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of the first embodiment of the current detection module proposed in this invention; Figure 2 This is a schematic diagram of the first structure of the second embodiment of the current detection module proposed in this invention; Figure 3This is a schematic diagram of the second structure of the second embodiment of the current detection module proposed in this invention; Figure 4 This is a schematic diagram of the third embodiment of the current detection module proposed in this invention; Figure 5 This is a flowchart illustrating the first embodiment of the bias current detection method proposed in this invention. Figure 6 This is a schematic diagram of the first test structure of the current detection module proposed in this invention; Figure 7 This is a schematic diagram of the second test structure of the current detection module proposed in this invention; Figure 8 This is a flowchart illustrating the second embodiment of the bias current detection method proposed in this invention. Figure 9 This is a flowchart illustrating the first embodiment of the current calibration method proposed in this invention.

[0018] Explanation of icon numbers: 10. Current detection circuit; 20. Sampling resistor; 30. Package housing; 101. Current detection chip; 102. Storage circuit; 103. Operational amplifier circuit; A1. First sampling interface; A2. Second sampling interface; VCC. Power supply interface; OUT. Output interface; Power. Output terminal of current calibration device.

[0019] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0023] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0024] Reference Figure 1 , Figure 1 This is a schematic diagram of the structure of the first embodiment of the current detection module proposed in this invention. Based on Figure 1 The first embodiment of the current detection module is proposed.

[0025] In this embodiment, the current detection module includes: Current detection circuit 10; The sampling resistor 20 has its first end connected to the first detection terminal of the current detection circuit 20 and used to connect to the circuit under test. The second end of the sampling resistor 20 is connected to the second detection terminal of the current detection circuit 10 and used to connect to the circuit under test.

[0026] It should be noted that the circuit under test is the circuit that needs to detect the current flowing through it. The circuit under test can be the charging or discharging circuit of the power supply within a smart device. The current detection circuit 10 is a circuit used to detect, convert, and output current signals. The core function of the current detection circuit 10 is to measure the voltage difference across the sampling resistor 20, that is, the voltage difference between the first and second detection terminals of the current detection circuit 10. It can also convert the voltage difference into a signal representing the magnitude of the current. The sampling resistor 20 is a precision resistor with a fixed resistance value in the milliohm range; the resistance value of the sampling resistor 20 can be 10 milliohms, 20 milliohms, 50 milliohms, etc. The sampling resistor 20 can convert the flowing current, forming a voltage difference across its terminals. The sampling resistor 20 is connected in series in the circuit under test where the current needs to be monitored. The first and second terminals of the sampling resistor, in addition to connecting to external circuits, are also directly connected to the first and second detection terminals inside the current detection circuit 10, respectively. At this time, the current flowing through the circuit under test will flow through the sampling resistor 20, and a small voltage drop proportional to the current will be generated across the sampling resistor 20. This voltage drop is directly and completely applied to the detection input terminal of the current detection circuit 10.

[0027] The first detection terminal and the second detection terminal refer to a pair of input terminals on the current detection circuit 10 used to connect to the sampling resistor 20 to detect the voltage difference across its two ends. These can typically be the differential input pair of a current sampling chip, or the non-inverting and inverting input terminals of an operational amplifier. The first detection terminal can be connected to the first end of the sampling resistor 20, and the second detection terminal can be connected to the second end of the sampling resistor 20.

[0028] In a specific implementation, the sampling resistor 20 is connected in series within the circuit to be tested, which can form a voltage difference between the current value in the circuit to be tested and the first terminal and the second terminal. The current detection circuit 10 can be used to detect the sampling current value flowing through the sampling resistor 20, that is, the current value obtained after converting the voltage difference between the sampling resistors 20, and then output the detection current value according to the sampling current value and the preset bias current value.

[0029] The sampling current value can be the current value directly measured and output by the current detection circuit 10. This sampling current value is the result obtained by the current detection circuit 10 after preliminary amplification and conversion of the voltage drop across the sampling resistor 20. It includes system errors introduced by the resistance deviation of the sampling resistor 20 itself and the inherent offset of the current detection circuit 10. The bias current value is a pre-determined and stored fixed calibration parameter. It characterizes the sampling current value output by this specific current detection module due to inherent hardware errors under the ideal condition that the actual current is zero. It can be understood as the "zero-point error" or "baseline offset" of the entire measurement system. The bias current value is determined based on the actual input current value and the sampling current value, that is, based on the resistance deviation of the sampling resistor 20 itself and the inherent offset of the current detection circuit 10. The detection current value is the sampling current value after calibration with the bias current value. This detection current value is the actual current flowing through the sampling resistor.

[0030] In this embodiment, the current detection module includes: a current detection circuit; a sampling resistor, wherein a first end of the sampling resistor is connected to a first detection terminal of the current detection circuit and is used to connect to the circuit under test, and a second end of the sampling resistor is connected to a second detection terminal of the current detection circuit and is used to connect to the circuit under test; the current detection circuit is used to detect the sampling current value flowing through the sampling resistor and output a detection current value based on the sampling current value and a preset bias current value. This invention, by presetting a bias current value within the current detection circuit, calibrates the sampling current value using the bias current value when the sampling current value is detected, eliminating errors within components such as the sampling resistor and the current detection circuit. This effectively improves the accuracy of current detection, as the accuracy of the detected current value is no longer limited by the initial accuracy of the sampling resistor.

[0031] Based on the first embodiment of the current detection module described above, a second embodiment of the current detection module of the present invention is proposed. (Refer to...) Figure 2 , Figure 2 This is a schematic diagram of the first structure of the second embodiment of the current detection module proposed in this invention.

[0032] exist Figure 2 In the above, the current detection circuit 10 includes: a current detection chip 101 with a storage circuit 102; the first detection terminal of the current detection chip 101 is connected to the first terminal of the sampling resistor 20, the second detection terminal of the current detection chip 101 is connected to the second terminal of the sampling resistor 20, and the input terminal of the current detection chip 101 is connected to the storage circuit 102; the bias current value is stored in the storage circuit 102.

[0033] It should be noted that the current detection chip 101 is an integrated detection chip that integrates multiple devices for current detection. The current detection chip 101 may include core functional circuits required for current detection, such as an amplifier circuit and an analog-to-digital converter circuit. The storage circuit 102 is a non-volatile memory circuit integrated inside or tightly packaged with the current detection chip 101. The storage circuit 102 is a storage circuit whose data is not lost after power failure. The storage circuit 102 can be a One-Time Programmable Read-Only Memory (OTPROM), an Electrically Erasable Programmable Read-Only Memory, or Flash Memory, etc. In this embodiment, the storage circuit 102 can permanently store the bias current value within the current detection chip 101. The first and second detection terminals of the current detection chip 101 are a pair of high-precision differential analog input pins led out from the chip and connected to the sampling resistor 20, used to detect weak differential voltage signals. The input terminal of the current detection chip 101 is a functional terminal on the current detection chip 101 used to read data from the internal storage circuit 102. The input terminal can be implemented through the chip's internal digital bus (such as I2C, SPI) or a dedicated data latch. The current detection chip 101 can access the bias current value stored in the storage circuit 102. The storage circuit 102 can also be writable. After the bias current value is written, the accuracy of the detected current value can be maintained for a relatively long time. However, if the time is too long, the resistance value of the sampling resistor 20 or the system-level error in the current sampling circuit 10 may change due to prolonged use of the components in the sampling resistor 20 or the current sampling circuit 10. In this case, the previously stored bias current value can be updated by rewriting the bias current value, which can effectively avoid the problem of inaccurate current detection caused by prolonged use.

[0034] In the specific construction process, the current detection chip 101 can be obtained first, and then the two ends of the sampling resistor 20 can be connected to the first detection terminal and the second detection terminal of the current detection chip 101 respectively with wires. At the same time, the current detection chip 101 is connected to the storage circuit 102 integrated on the current detection chip 101 through its input terminal, so as to read the bias current value stored therein at any time.

[0035] In a specific implementation, when current flows through the sampling resistor 20 in the circuit under test, the voltage values ​​at the first and second terminals of the sampling resistor 20 are input to the first and second detection terminals of the current detection chip 101. The current detection chip 101 can amplify, suppress common-mode noise, and perform analog-to-digital conversion on the detected sampling current value to obtain a processed sampling current value; then, it reads the pre-programmed bias current value from the storage circuit 102, and finally uses the bias current value to calibrate the sampling current value to obtain an accurate detection current value and output it.

[0036] Furthermore, by setting up the current sampling chip 101, current detection, signal conditioning, analog-to-digital conversion, and parameter storage can all be integrated, reducing the length of the connection lines between various components, thereby reducing parasitic inductance, resistance, and electromagnetic interference introduced by external leads.

[0037] Reference Figure 3 , Figure 3 This is a schematic diagram of the second structure of the second embodiment of the current detection module proposed in this invention.

[0038] exist Figure 3 In the above, the current detection circuit 101 includes: an operational amplifier circuit 103 and a storage circuit 102; the first input terminal of the operational amplifier circuit 103 is connected to the first terminal of the sampling resistor 20, the second input terminal of the operational amplifier circuit 103 is connected to the second terminal of the sampling resistor 20, and the bias terminal of the operational amplifier circuit 103 is connected to the storage circuit 102. The bias current value is stored in the storage circuit 102.

[0039] It should be noted that the operational amplifier circuit 103 is used to differentially amplify the voltage difference between the first and second terminals of the sampling resistor 20. The operational amplifier circuit 103 can be constructed by combining one or more operational amplifiers and multiple resistors. Upon receiving the voltage difference across the sampling resistor 20, the operational amplifier circuit 103, after amplification and common-mode noise suppression, outputs a voltage signal with a larger amplitude that is proportional to the sampling current. The first input terminal of the operational amplifier circuit 103 can be the non-inverting input terminal of the operational amplifier, and the second input terminal can be the inverting input terminal of the operational amplifier. The first and second input terminals are connected to the two ends of the sampling resistor 20 through a high-impedance resistor. The bias terminal of the operational amplifier circuit 103 is the port used to read the bias current value in the storage circuit 102. The bias terminal of the operational amplifier circuit 103 can be the offset voltage zero-adjustment pin on the operational amplifier.

[0040] The storage circuit 102 is not integrated inside the operational amplifier circuit 103. It is connected to the operational amplifier circuit 103 through the bias terminal of the operational amplifier circuit 103. During the current detection process, a bias current value can be generated at the bias terminal of the operational amplifier circuit 103.

[0041] In a specific implementation, when current flows through the sampling resistor 20 in the circuit under test, the voltage values ​​at the first and second terminals of the sampling resistor 20 are input through the first and second input terminals of the operational amplifier circuit 103. The operational amplifier circuit 103 can amplify the detected sampling current value, suppress common-mode noise, and perform analog-to-digital conversion to obtain a processed sampling current value; then, it reads the pre-programmed bias current value from the storage circuit 102, and finally uses the bias current value to calibrate the sampling current value to obtain an accurate detection current value, which is then output through the output terminal of the operational amplifier circuit 103.

[0042] In this embodiment, with the operational amplifier circuit 103 provided, the amplification factor of the operational amplifier within the operational amplifier circuit 103 can be adjusted. Combined with the bias current value, it can accurately adapt to current detection under different accuracy requirements. For example, it can accurately detect current values ​​at the microampere level, effectively improving the flexibility of current detection under low cost conditions.

[0043] Based on the first or second embodiment of the current detection module described above, a third embodiment of the current detection module of the present invention is proposed. (Refer to...) Figure 4 , Figure 4 This is a schematic diagram of the third embodiment of the current detection module proposed in this invention.

[0044] In this embodiment, the current detection module further includes: The current detection circuit 10 and the sampling resistor 20 are disposed inside the encapsulation housing 30. The encapsulation housing 30 is provided with a first sampling interface A1 and a second sampling interface A2; The first sampling interface A1 is connected to the first terminal of the sampling resistor 20, and the second sampling interface A2 is connected to the second terminal of the sampling resistor 20; The first sampling interface A1 and the second sampling interface A2 are connected to the circuit to be tested.

[0045] It should be noted that the enclosure 30 is a physical shell used to house, fix, and protect the current detection circuit 10 and the sampling resistor 20. The enclosure 30 can be made of insulating material to electrically insulate the current detection circuit 10 and the sampling resistor 20 from external devices and to prevent environmental factors such as dust and water from affecting them. The first sampling interface A1 and the second sampling interface A2 are two electrical connection ports extending from the enclosure 30. By placing the sampling resistor 20 between the first sampling interface A1 and the second sampling interface A2 and establishing a connection, the sampling resistor 20 can be connected in series within the circuit under test when the first sampling interface A1 and the second sampling interface A2 are connected to the circuit under test. The first sampling interface A1 and the second sampling interface A2 can be metal pins, pads, pins, or sockets.

[0046] In the specific setup process, the sampling resistor 20 and the current detection circuit 10 can be connected first, and then fixed by a carrier board. The carrier board is encapsulated in the encapsulation housing 30. Finally, the two ends of the sampling resistor 20 are connected to the first sampling interface A1 and the second sampling interface A2 respectively.

[0047] In this embodiment, the resistance value of the sampling resistor 20 can be fixed and encapsulated by the enclosure 30. During current detection, the circuit under test is connected through the first sampling interface A1 and the second sampling interface A2. The voltage value across the sampling resistor 20 is used to determine the sampling current value. Finally, the sampling current value is calibrated using a bias current value. This allows for accurate detection of the current flowing through the circuit under test without needing to select different resistance values ​​for the sampling resistor 20 for different sampling currents. Furthermore, the enclosure 30 provides protection by isolating the sampling resistor 20, reducing external interference, and effectively extending the service life of the sampling resistor 20 for accurate detection.

[0048] In addition, a power supply interface VCC is provided on the encapsulation housing 30; The power supply interface VCC is connected to the power supply terminal of the current detection circuit 10 and is also used to connect to an external power source.

[0049] It should be noted that the power supply interface VCC is an electrical connection terminal led out from the package housing 30 for connecting to an external operating power supply, providing the necessary voltage and current for the normal operation of the current sensing circuit 10. The power supply interface VCC can be a separate metal pin, a pad, or a power supply pin in a multi-pin connector integrated with the sampling interface. The power supply terminal of the current sensing circuit 10 is used to receive the voltage and current input from an external power source, such as the positive power supply VCC or VDD pin and the ground GND or VSS pin of the current sensing chip 101. The external power supply is used to provide the necessary voltage and current to the current sensing circuit 10. The external power supply can provide a stable low-voltage power supply to the current sensing circuit 10, such as 3.3V or 5V low-voltage DC.

[0050] In a practical implementation, when an external power supply powers the current detection circuit 10 through the power supply interface VCC, the current of the circuit to be detected flows into the sampling resistor 20 through the first sampling interface A1 and then flows out through the second sampling interface A2. The voltage drop across the sampling resistor 20 can be normally detected through the first and second detection terminals, thereby determining the sampling current.

[0051] In this embodiment, when the current detection circuit 10 and the sampling circuit 20 are packaged, the positions of the current detection circuit 10 and the sampling resistor 20 are relatively fixed, and the connection between the two and the connection between the two and external devices are also fixed. Therefore, during the current detection process, there is a fixed impedance between the connecting lines. When the bias current value is determined, the obtained detection current value will not be affected by the position changes of the sampling resistor 20 and the current detection circuit 10.

[0052] In addition, in this embodiment, the encapsulation housing 30 is also provided with an output interface OUT, which can be connected to a host computer to output the detected current value.

[0053] Based on the current detection module described in any of the above embodiments, this invention also provides a bias current detection method, which is applied to a current calibration device connected to the current detection module in any of the above embodiments. (Refer to...) Figure 5 , Figure 5 This is a flowchart illustrating the first embodiment of the bias current detection method proposed in this invention.

[0054] In this embodiment, the bias current detection method includes: Step S10: Obtain at least two actual input current values ​​that are input to the sampling resistor in the current detection module.

[0055] It should be noted that the current calibration device is used to calculate the bias current value based on the resistance deviation of the sampling resistor 20 and the inherent offset of the current detection circuit 10. The accuracy of the sampling resistor 20 can cause inaccurate current detection during the current detection process. Similarly, the operational amplifiers and other structures within the current detection circuit 10 exhibit a certain degree of current offset, such as zero-point drift.

[0056] It should be understood that the actual input current value is the current applied to the sampling interface of the current detection module, that is, the current input to the sampling resistor 20 through the first sampling interface A1. During current detection, the actual input current value serves as the reference for the detected current value. If the detected current value equals the actual input current value, the detected current value can be considered accurate. When the sampling resistor 20 is connected in series within the circuit under test, multiple current values ​​with different amplitudes can be input to the circuit under test through different power supplies. This actual input current value will flow through the sampling resistor 20 and be acquired by the current sampling circuit 10.

[0057] In practical implementation, multiple actual input current values ​​to be input to the sampling resistor 20 can be determined by pre-setting. For example, two actual input current values ​​can be pre-set to the current calibration device, and then the current calibration device can input each actual current value to the circuit under test to determine the actual current value input to the sampling resistor 20 in the current detection module.

[0058] Step S20: Obtain the sampled current value output by the current detection module corresponding to each actual input current value.

[0059] It should be understood that when an actual current value is input, current will flow through the sampling resistor 20, and after being detected by the current detection circuit 10, a corresponding sampled current value can be obtained. The sampled current value refers to the original current value that the current detection circuit 10 directly converts and outputs based on the voltage drop of the sampling resistor 20 when the actual input current value flows through it. The sampled current value includes all errors within the current detection module.

[0060] In practical implementation, when each actual input current value is input to the circuit under test, the current detection circuit 10 can be used to sample the current to obtain the sampled current value corresponding to each actual input current value. Of course, to consider the accuracy of the sampled current value, in this embodiment, current detection can be performed for each actual input current value to obtain multiple sampled current values. Then, the current values ​​of multiple sampling points are processed to obtain the sampled current value corresponding to the actual input current value. For example, the current calibration device outputs and records the first actual input current value. After the current stabilizes, the current calibration device reads and records the sampled current value output by the current detection module at this time, which is the sampled current value corresponding to the first actual input current value. Then, the current calibration device outputs and records the second actual input current value. After the current stabilizes, the current calibration device reads and records the sampled current value output by the current detection module at this time, which is the sampled current value corresponding to the second actual input current value.

[0061] Step S30: Determine the bias current value based on the actual input current value and the sampled current value.

[0062] It should be understood that the deviation between the actual input current value and the sampled current value is the bias current value caused by the resistance error of the sampling resistor 20 and the system error within the current detection circuit 10. Therefore, given the actual input current value and the sampled current value detected by the current detection module, the bias current value can be directly calculated based on the actual input current value and the sampled current value. Then, the current calibration device can input the calculated bias current value into the storage circuit within the current detection module via a write input method.

[0063] In practical implementation, the output of the current calibration device can be connected to the first sampling interface A1 of the current detection module, and then connected to a low level through the second sampling interface A2 to form a complete power supply branch. The current calibration device can then input two actual input current values ​​of different amplitudes sequentially and receive the sampled current value output by the current detection module. Finally, it calculates the bias current value based on the sampled current value and the actual input current value, and writes the bias current value into the storage circuit 102 within the current detection circuit 10. To further improve calibration accuracy and reliability, more than two actual input current values ​​can be applied, and multiple corresponding sampled current values ​​can be acquired for each actual input current value.

[0064] Reference Figure 6 and Figure 7 ,exist Figure 6The high voltage provided by the output terminal Power of the current calibration device powers the current detection circuit 10. The sampling resistor 30 is positioned closer to the output terminal of the current calibration device than other loads, and the second terminal of the sampling resistor 20 is grounded through another load. In the specific connection process of the test circuit, the output voltage terminal of the current calibration device can be connected to the power supply interface VCC and the first sampling interface A1 of the package housing 30, and the second sampling interface A2 on the package housing 30 can be connected to other loads, which are then grounded. Figure 7 In this circuit, the high voltage provided by the output terminal Power of the current calibration device powers the current detection circuit 10. The sampling resistor 30 is positioned closer to ground than other loads. The first end of the sampling resistor 20 is connected to the second end GND1 of the other loads, which is then connected to the output terminal of the current calibration device. In the specific connection process of the test circuit, the output voltage terminal of the current calibration device can be connected to the power supply interface VCC of the package housing 30 and the first end of the other loads. Then, the second end of the other loads is connected to the first sampling interface A1, and the second sampling interface A2 on the package housing 30 is grounded.

[0065] In this embodiment, by testing the current sampling module, the resistance error of the sampling resistor 20 in each current sampling module and the bias current value corresponding to the system-level error of the current detection circuit 10 can be determined. Then, the bias current can be set specifically in the current detection module, which can effectively improve the detection accuracy of the current detection module without changing the inherent accuracy of the specific device.

[0066] Reference Figure 8 , Figure 8 This is a flowchart illustrating the second embodiment of the bias current detection method proposed in this invention.

[0067] In this embodiment, step S30 specifically includes: Step S31: Determine the current gain value of the current detection circuit based on the actual input current value and the sampled current value.

[0068] It should be noted that the current gain value refers to the overall transfer factor or amplification factor of the operational amplifier and other devices installed in the current detection circuit 10. In an ideal linear system, it represents the ideal proportional relationship between the sampled current value and the actual input current value. However, due to factors such as the resistance deviation of the sampling resistor 20 and amplifier gain error, the current gain value of the actual system may not be the coefficient corresponding to the ideal proportional relationship.

[0069] It should be understood that the sampled current value is actually the actual input current value after amplitude adjustment by the operational amplifier and other devices within the current detection circuit 10. Therefore, given the actual input current value and the sampled current value, the current gain value of the current detection circuit 10 can be directly calculated using the sampled current value and the actual input current value.

[0070] Step S31 specifically includes: Step S311: Obtain the average current value of each sampled current value corresponding to each actual input current value.

[0071] It should be noted that the average current value of each sampled current value refers to the current value obtained by taking the arithmetic average of the sampled current values ​​output by the current detection module multiple times under the condition of a stable actual input current value. Calculating the average current value can effectively avoid detection deviations in the sampled current value acquisition process, which may occur during periods of unstable power supply or current fluctuations.

[0072] In actual calculations, when multiple sampled current values ​​corresponding to the actual input current value are collected, the formula can be used: (1) Calculate and determine the sampling current value, where, The final average current value is obtained. For a given actual input current value, there are multiple sampled current values. This represents the number of sampled current values.

[0073] Step S312: Determine the current gain value of the current detection circuit based on the average current value and the corresponding actual input current value.

[0074] It should be understood that, in order to determine the current gain value more accurately, in this embodiment, the current gain value of the current detection circuit can be calculated using multiple actual input current values ​​and the average current value of the corresponding sampled current values. For example, when using two actual input current values ​​and two corresponding average current values, the difference between the two actual input current values ​​can be used to obtain the first difference, and the difference between the two average current values ​​can be used to obtain the second difference. Then, the two differences can be divided to obtain the current gain value of the current detection circuit 10. Specifically, the formula Gain = (Ireal1- Ireal2) / (Before1 - Before2) (2) can be used for calculation. Wherein is the current gain value, Ireal1 is the first average current value, Ireal2 is the second average current value, Before1 is the first actual input current value, and Before2 is the second actual input current value.

[0075] In the specific determination process, at least two actual input current values ​​with different amplitudes can be output by the current calibration device. After stabilizing, the current calibration device continuously acquires multiple sampled current values ​​output by the current detection module corresponding to each actual input current value in a short period of time, calculates the average current value, and finally calculates the current gain value based on the actual input current value and the average current value.

[0076] By using multiple actual input current values ​​and the average current value corresponding to each actual input current value, the accuracy of calibration results can be effectively enhanced. This enables high-precision measurements over a wide range from microamperes to amperes, especially in low-current scenarios where the signal amplitude is low, easily overwhelmed by noise, or has a poor signal-to-noise ratio.

[0077] Step S32: Determine the bias current value based on the current gain value, the sampled current value, and the actual input current value.

[0078] It should be noted that before determining the bias current value, considering that the operational amplifier circuit within the current detection circuit 10 will amplify the current value during the sampling process, the theoretical input current value can be determined first based on the current gain value and the sampled current value. Then, the current difference between the theoretical and actual input current values ​​can be used as the bias current value. The theoretical input current value is derived from the sampled current value and the amplification factor of the current detection circuit 10. In the case where the current detection circuit is ideal and the bias current value is 0, the current value is obtained by reverse deduction based solely on the measured sampled current value and the calculated actual current gain value.

[0079] In practical implementation, the theoretical input current value can be calculated directly using the current gain value, the sampled current value, and the actual input current value. Then, the bias current value can be obtained by subtracting the theoretical input current value from the actual input current value. Alternatively, the bias current value can be calculated directly using the formula: Current_Offset = Before1 - (Ireal1 / Gain) (3). Where Current_Offset is the bias current value, Before1 is an actual input current value, Ireal1 is the average current value corresponding to the actual input current value, and Gain is the current gain value.

[0080] In this embodiment, the current gain value is determined by using multiple sets of actual input current values ​​and average current values, and the current gain value is calculated by the difference. Even if there are slight fluctuations in a single actual input current value or sampled current value, the current gain value and bias current value can still be obtained accurately.

[0081] Based on the current detection module described in any of the above embodiments, this invention also provides a sampling current calibration method, which is applied to the current detection module connection in any of the above embodiments. (Refer to...) Figure 9 , Figure 9 This is a flowchart illustrating the first embodiment of the current calibration method proposed in this invention.

[0082] The current calibration method includes: Step S100: Detect the sampling current flowing through the sampling resistor to obtain the sampling current value; Step S200: The sampling current value is calibrated according to the preset bias current value to obtain the detection current value.

[0083] It should be noted that the bias current value in this embodiment can be obtained through any of the above-described bias current detection methods and stored in the storage circuit 102 by the current calibration device.

[0084] The sampled current value can be the current value directly measured and output by the current detection circuit 10. The bias current value is a pre-determined and stored fixed calibration parameter. It characterizes the sampled current value output by the specific current detection module due to inherent hardware errors under the ideal condition that the actual current is zero. It can be understood as the "zero-point error" or "baseline offset" of the entire measurement system. The bias current value is determined based on the actual input current value and the sampled current value, that is, based on the resistance deviation of the sampling resistor 20 and the inherent offset of the current detection circuit 10. The detected current value is the sampled current value after calibration with the bias current value, and this detected current value is the actual current flowing through the sampling resistor.

[0085] In a specific implementation, the current detection circuit 10 can continuously measure the real-time voltage drop across the sampling resistor 20, and process it through internal amplification, analog-to-digital conversion and other devices to obtain the sampling current value. Then, the current detection circuit 10 uses the internally stored bias current value to calibrate the sampling current value, thereby obtaining an accurate detection current value, which is then output through the current detection circuit 10.

[0086] In this embodiment, when the sampled current value is detected, the sampled current value is calibrated using the bias current value to eliminate errors in components such as the sampling resistor and the current detection circuit. This ensures that the accuracy of the detected current value is no longer limited by the initial accuracy of the sampling resistor, effectively improving the accuracy of current detection.

[0087] Based on any of the above embodiments, a smart device is proposed, the smart device comprising: a device body and a current detection module as described in any of the above embodiments, the current detection module being connected to the circuit to be detected within the device body.

[0088] The circuit under test is used to detect the current within the device. This circuit can be a charging or discharging circuit of the power supply within a smart device. Smart devices can be devices such as headphones or VR headsets.

[0089] When it is necessary to detect the charging current or discharging current in a smart device, the current detection module can set the internal sampling resistor 20 in series in the charging circuit or discharging circuit. The current detection circuit 10 collects the voltage difference across the sampling resistor 20 and determines the sampling current value based on the voltage difference. The sampling current value is further calibrated using the bias current value, so as to output an accurate detection current value at the output terminal of the current detection module.

[0090] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A current detection module, characterized in that, include: Current detection circuit; A sampling resistor, wherein the first end of the sampling resistor is connected to the first detection terminal of the current detection circuit and is used to connect to the circuit to be tested; and the second end of the sampling resistor is connected to the second detection terminal of the current detection circuit and is used to connect to the circuit to be tested. The current detection circuit is used to detect the sampling current value flowing through the sampling resistor, and output a detection current value based on the sampling current value and a preset bias current value. The bias current value is determined based on the actual input current value and the sampling current value.

2. The current detection module as described in claim 1, characterized in that, The current detection circuit includes: a current detection chip with a storage circuit; a first detection terminal of the current detection chip is connected to a first terminal of the sampling resistor, a second detection terminal of the current detection chip is connected to a second terminal of the sampling resistor, and an input terminal of the current detection chip is connected to the storage circuit. The bias current value is stored in the storage circuit.

3. The current detection module as described in claim 1, characterized in that, The current detection circuit includes an operational amplifier circuit and a storage circuit; the first input terminal of the operational amplifier circuit is connected to the first terminal of the sampling resistor, the second input terminal of the operational amplifier circuit is connected to the second terminal of the sampling resistor, and the bias terminal of the operational amplifier circuit is connected to the storage circuit. The bias current value is stored in the storage circuit.

4. The current detection module as described in any one of claims 1 to 3, characterized in that, The current detection module also includes: The current detection circuit and the sampling resistor are disposed inside the package housing; The encapsulation housing is provided with a first sampling interface and a second sampling interface; The first sampling interface is connected to the first terminal of the sampling resistor, and the second sampling interface is connected to the second terminal of the sampling resistor; The first sampling interface and the second sampling interface are connected to the circuit to be tested.

5. The current detection module as described in claim 4, characterized in that, The encapsulation housing is also provided with a power supply interface; The power supply interface is connected to the power supply terminal of the current detection circuit and is also used to connect to an external power source.

6. A bias current detection method, characterized in that, The bias current detection method is applied to a current calibration device, which is connected to the current detection module according to any one of claims 1 to 5. The bias current detection method includes: Obtain at least two actual input current values ​​that are input to the sampling resistor within the current detection module; Obtain the sampled current value output by the current detection module corresponding to each of the actual input current values; The bias current value is determined based on the actual input current value and the sampled current value.

7. The bias current detection method as described in claim 6, characterized in that, Determining the bias current value based on the actual input current value and the sampled current value includes: The current gain value of the current detection circuit is determined based on the actual input current value and the sampled current value. The bias current value is determined based on the current gain value, the sampled current value, and the actual input current value.

8. The bias current detection method as described in claim 7, characterized in that, Determining the current gain value of the current detection circuit based on the actual input current value and the sampled current value includes: Obtain the average current value of each sampled current value corresponding to each actual input current value; The current gain value of the current detection circuit is determined based on the average current value and the corresponding actual input current value.

9. A sampling current calibration method, characterized in that, The current detection circuit is applied to the current detection module according to any one of claims 1 to 5; The current calibration method includes: The sampling current value is obtained by detecting the sampling current flowing through the sampling resistor; The sampled current value is calibrated according to a preset bias current value to obtain a detected current value, wherein the bias current value is obtained by the bias current detection method according to any one of claims 6 to 9.

10. A smart device, characterized in that, The intelligent device includes: a device body and a current detection module as described in any one of claims 1 to 5, wherein the current detection module is connected to the circuit to be detected within the device body.

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