A multi-input voltage high-precision compensation circuit, compensation method and device

Abstract

This invention provides a high-precision compensation circuit, method, and device for multiple input voltage channels. It detects the input signal to the MCU processor using at least one first detection circuit, and performs voltage detection and compensation on multiple first detection circuits using a second detection circuit. Based on the voltage difference, it performs differential voltage compensation, achieving consistent control of multiple input voltage channels. Through simple calculations, it eliminates errors caused by temperature variations in diode forward voltage and leakage current of clamping diodes, improving detection accuracy. The compensation circuit, combining the first and second detection circuits, achieves an error of less than 0.05V within an input voltage range of 0~36V.

Description

Technical Field

[0001] This invention relates to the field of circuit equalization technology, and in particular to a high-precision compensation circuit, compensation method and device for multiple input voltages. Background Technology

[0002] In current input signal detection circuits, diodes are often added to the input signal detection port to pass reverse power connection and various pulse tests to meet DV (Digital Voltage) requirements; these are called anti-reverse diodes. However, when diodes are added to the detection circuit, the voltage hysteresis range set by measurement at room temperature often fails due to differences in diode models and variations in the diode's forward voltage with temperature. This can lead to the diodes becoming dormant under normal operating voltage but not dormant under abnormal input voltages. Furthermore, existing solutions require manual measurement and statistical compensation for this error, which cannot guarantee normal product operation and is also a waste of human resources. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention proposes a high-precision compensation circuit, method, and device for multiple input voltages. By adding a first detection circuit and a second detection circuit, precise compensation and control of multiple input voltages are achieved.

[0004] Specifically, the present invention provides a high-precision compensation circuit for multiple input voltages, comprising at least a first detection circuit and a second detection circuit; one end of the first detection circuit and the second detection circuit are connected to a connector, and the other end is connected to an MCU processor; the first detection circuit is used to detect the input signal of the MCU processor; the second detection circuit is used to compensate for the voltage difference caused by at least one of the first detection circuits.

[0005] Preferably, the first detection circuit includes at least: a first clamping circuit, a first voltage divider circuit, a first noise filtering circuit, and a first anti-reverse component; one end of the clamping circuit is connected to a first power supply, and the other end is connected to the first voltage divider circuit. The voltage is controlled within a preset range by the first voltage divider circuit, and after the noise is removed by the first noise filtering circuit, it is input to the MCU processor; the other end of the first voltage divider circuit is connected to a connector via the anti-reverse component.

[0006] Preferably, the first voltage divider circuit includes a first resistor, a second resistor, and a third resistor; one end of the first resistor is connected to the negative terminal of the first anti-reverse component, and the other end is connected to the first noise filtering circuit; the second resistor and the third resistor are connected in parallel with the first resistor.

[0007] Preferably, the first noise filtering circuit includes a fourth resistor, a first capacitor, and a second capacitor; one end of the fourth resistor is connected to the positive terminal of the first resistor and the first clamping circuit, respectively; the first capacitor and the second capacitor are connected in parallel with the fourth resistor.

[0008] Preferably, the second detection circuit includes at least: a second clamping circuit, a second voltage divider circuit, a second noise filtering circuit, and a second anti-reverse component; one end of the second clamping circuit is connected to a second power supply, and the other end is connected to the second voltage divider circuit; one end of the second voltage divider circuit is connected to a third power supply, and the other end is connected to the second noise filtering circuit and the second anti-reverse component, respectively.

[0009] The second voltage divider circuit is an equivalent resistance circuit, and the resistance of the second voltage divider circuit is equal to the resistance value of the first voltage divider circuit.

[0010] The second clamping circuit in this invention is used to eliminate the voltage difference caused by the leakage current of the first clamping circuit flowing through the second resistor and the third resistor.

[0011] Preferably, the second noise filtering circuit includes a fifth resistor, a third capacitor, and a fourth capacitor; one end of the fifth resistor is connected to the equivalent resistance and the positive terminal of the second anti-reverse component, respectively; the third capacitor and the fourth capacitor are connected in parallel with the fifth resistor.

[0012] In this invention, the first clamping circuit and the second clamping circuit preferably use Schottky diodes, but are not limited thereto.

[0013] In this invention, the first anti-reverse component and the second anti-reverse component are preferably anti-reverse diodes, but are not limited thereto.

[0014] The first and second anti-reverse components use the same diode model to eliminate forward voltage error.

[0015] In this invention, the types of diodes, resistors, and capacitors used can be selected according to actual conditions, and are not limited thereto.

[0016] In this invention, the number and size of resistors and capacitors used in the first voltage divider circuit, the first noise filtering circuit, the second voltage divider circuit, and the second noise filtering circuit can be increased or decreased according to actual conditions, and are not limited thereto.

[0017] In this invention, the model of the MCU processor can be adjusted according to project requirements, as long as it has ADC detection function.

[0018] As another preferred embodiment, the present invention also provides a high-precision compensation method for multiple input voltages, wherein the compensation method includes the following steps:

[0019] S1: The input signal to the MCU processor is detected by at least one first detection circuit;

[0020] S2: Based on the detection result of the first detection circuit, the pressure difference caused by the first detection circuit is detected by the second detection circuit;

[0021] S3: Based on the pressure difference, perform pressure difference compensation to complete the consistent control of multiple input voltages.

[0022] As another preferred embodiment, the present invention also provides a device for detecting power supply and external interface signals, the device employing a multi-channel input voltage high-precision compensation circuit as described above.

[0023] In summary, this invention provides a high-precision compensation circuit, compensation method, and device for multiple input voltages. By using a second detection circuit to perform voltage detection and compensation on multiple first detection circuits, the compensation circuit combining the first and second detection circuits can achieve an error of less than 0.05V within an input voltage range of 0~36V.

[0024] The beneficial effects of this invention are:

[0025] 1. By adding a second detection circuit to detect the voltage difference across the diode, errors caused by temperature variations in the diode's forward voltage and leakage current of the clamping diode can be eliminated through simple calculations, thereby improving detection accuracy.

[0026] 2. The second clamping circuit uses a Schottky diode to effectively eliminate the voltage difference caused by the leakage current of the first clamping circuit flowing through the second and third resistors.

[0027] 3. The first and second anti-reverse components use the same diode model to eliminate forward voltage error.

[0028] 4. The equalization time can be estimated by using the curve of PTC resistance or corresponding voltage versus equalization time.

[0029] 5. A wide range of voltages can be selected for the power supply.

[0030] 6. The circuit can be built using simple resistors and diodes. At the same time, this compensation value can also be used to compensate for other input signals on the same circuit board, achieving improved accuracy for multiple detections with a single circuit, and effectively reducing costs. Attached Figure Description

[0031] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0032] Figure 1 This is a schematic diagram of a high-precision compensation circuit for multiple input voltages according to the present invention.

[0033] Figure 2 This is a flowchart of a high-precision compensation method for multiple input voltages according to the present invention. Implementation

[0034] To enable those skilled in the art to better understand the present invention, 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 some embodiments of the present invention, and not all embodiments. 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.

[0035] The present invention provides a high-precision compensation circuit for multiple input voltages, comprising at least a first detection circuit and a second detection circuit; one end of the first detection circuit and the second detection circuit are connected to a connector, and the other end is connected to an MCU processor; the first detection circuit is used to detect the input signal of the MCU processor; the second detection circuit is used to compensate for the voltage difference caused by at least one of the first detection circuits.

[0036] Preferably, the first detection circuit includes at least: a first clamping circuit, a first voltage divider circuit, a first noise filtering circuit, and a first anti-reverse component; one end of the clamping circuit is connected to a first power supply, and the other end is connected to the first voltage divider circuit. The voltage is controlled within a preset range by the first voltage divider circuit, and after the noise is removed by the first noise filtering circuit, it is input to the MCU processor; the other end of the first voltage divider circuit is connected to a connector via the anti-reverse component.

[0037] Preferably, the first voltage divider circuit includes a first resistor, a second resistor, and a third resistor; one end of the first resistor is connected to the negative terminal of the first anti-reverse component, and the other end is connected to the first noise filtering circuit; the second resistor and the third resistor are connected in parallel with the first resistor.

[0038] Preferably, the first noise filtering circuit includes a fourth resistor, a first capacitor, and a second capacitor; one end of the fourth resistor is connected to the positive terminal of the first resistor and the first clamping circuit, respectively; the first capacitor and the second capacitor are connected in parallel with the fourth resistor.

[0039] Preferably, the second detection circuit includes at least: a second clamping circuit, a second voltage divider circuit, a second noise filtering circuit, and a second anti-reverse component; one end of the second clamping circuit is connected to a second power supply, and the other end is connected to the second voltage divider circuit; one end of the second voltage divider circuit is connected to a third power supply, and the other end is connected to the second noise filtering circuit and the second anti-reverse component, respectively.

[0040] The second voltage divider circuit is an equivalent resistance circuit, and the resistance of the second voltage divider circuit is equal to the resistance value of the first voltage divider circuit.

[0041] The second clamping circuit in this invention is used to eliminate the voltage difference caused by the leakage current of the first clamping circuit flowing through the second resistor and the third resistor.

[0042] Preferably, the second noise filtering circuit includes a fifth resistor, a third capacitor, and a fourth capacitor; one end of the fifth resistor is connected to the equivalent resistance and the positive terminal of the second anti-reverse component, respectively; the third capacitor and the fourth capacitor are connected in parallel with the fifth resistor.

[0043] In this invention, the first clamping circuit and the second clamping circuit preferably use Schottky diodes, but are not limited thereto.

[0044] In this invention, the first anti-reverse component and the second anti-reverse component are preferably anti-reverse diodes, but are not limited thereto.

[0045] The first and second anti-reverse components use the same diode model to eliminate forward voltage error.

[0046] In this invention, the types of diodes, resistors, and capacitors used can be selected according to actual conditions, and are not limited thereto.

[0047] In this invention, the number and size of resistors and capacitors used in the first voltage divider circuit, the first noise filtering circuit, the second voltage divider circuit, and the second noise filtering circuit can be increased or decreased according to actual conditions, and are not limited thereto.

[0048] In this invention, the model of the MCU processor can be adjusted according to project requirements, as long as it has ADC detection function.

[0049] In one embodiment, such as Figure 1 The diagram shows a high-precision multi-input voltage compensation circuit provided in this invention, wherein:

[0050] In the first detection circuit, diode D5 is used for reverse protection; resistors R4, R5, and R6 are used for voltage division to reduce the detection voltage to a range detectable by the MCU processor; Schottky diode D6 clamps the voltage across R5 to R6, preventing damage to the microprocessor when the input voltage is too high; resistor R7 limits current, allowing the MCU processor pins to withstand electrostatic discharge and pulse shocks. Placing Schottky diode D6 at the front end prevents leakage current from flowing through R5 and R4, thus avoiding larger errors, and also allows for faster response to overvoltage, preventing damage to the internal pull-up diodes of the MCU processor pins first. Capacitors C17 and C18 are used to filter out noise interference.

[0051] The second detection circuit mainly consists of a compensation diode, an equivalent resistor, and a power supply. Through resistor voltage division and the clamping characteristics of the diode, the diode voltage difference can be detected through a single AD detection port, and the voltage difference value is then sent to the MCU processor for input voltage calculation. Resistors R3, C15, and C16 have the same function as R7, C17, and C18 in the first detection circuit, used for safety protection and error elimination to ensure circuit consistency. The sum of the resistances of resistors R2 and R1 must equal R6 plus R5 and R4 to compensate for the actual current flowing through D5. The Schottky diode D3 is used to eliminate errors caused by the leakage current of D6 flowing through R4 and R5. The leakage current of D3 increases the current flowing through diode D4, resulting in an increased voltage drop across D4, thus eliminating the error.

[0052] The error analysis performed in this invention is specifically as follows:

[0053] The main sources of error in the first detection circuit include: resistor accuracy error, forward voltage error of D5 anti-reverse diode, and leakage current error of D6 Schottky diode.

[0054] Resistance accuracy error, which is determined by the voltage divider formula. It can be concluded that the error is largest when R6 deviation is 1% and R5 and R4 deviation are 2%, with a deviation from the actual value of approximately 0.66889%.

[0055] Diode leakage current error is given by the formula: It can be concluded that the error is positively correlated with the resistance values ​​of R5 and R4. Given that the leakage current of the diode is usually in the Ua range, the error is about 0.000092V with a 9.2K resistor, which is much less than 1%.

[0056] The anti-reverse diode has an error range of 0.8V to 0.2V, depending on its characteristics. The forward voltage can vary from -40℃ to 150℃. The absolute error is 0.6V, meaning that the same input voltage can cause different operating conditions due to variations in voltage judgment logic at different temperatures.

[0057] In this invention, the largest error comes from the anti-reverse diode, followed by the resistor accuracy, and the smallest is the leakage current error.

[0058] The second detection circuit, tested through circuit simulation and actual measurement using PSpice for TI software, achieves an error of less than 0.05V within an input voltage range of 0-36V. The main principle is based on the fact that diodes of the same type can generate the same voltage difference under the same impedance conditions.

[0059] Error analysis of the compensation circuit reveals that the main factors affecting the accuracy of this supplementary circuit are the power supply (VCC_DIO) of the second detection circuit, the equivalent resistances (R1, R2), and the diode types (D3, D4). The compensation diode D4 is selected to be the same type as the anti-reverse diode D5 to eliminate forward voltage error; the equivalent resistance is selected to be the same as the input resistance value of the first detection circuit, i.e., R1 + R2 = R4 + R5 + R6.

[0060] A wide voltage range can be selected for the power supply. Two options are presented here. When VCC_DIO uses the voltage between the anti-reverse diode D5 and R6, the simulation error can be less than 0.01V. The second option is to use the MCU_VDD_3V3 power supply for VCC_DIO, in which case the error can be less than 0.05V over the entire temperature range. The key to selecting the power supply for this compensation circuit is the voltage difference. The smaller the voltage difference between VCC_DIO and the input sensing voltage at the front end of diode D5, the smaller the error.

[0061] This invention allows for circuit construction using simple resistors and diodes. Simultaneously, this compensation value can be used to compensate for other input signals on the same circuit board, achieving improved accuracy for multiple detections within a single circuit. As shown in the multi-channel detection circuit diagram below, as long as D7 and D4 remain consistent, and the sum of the resistance values ​​of R10, R9, and R8 remains consistent with the sum of R1 and R2, multiple detection circuits can be replicated to detect different input voltages.

[0062] As another preferred embodiment, the present invention also provides a high-precision compensation method for multiple input voltages, wherein the compensation method includes the following steps, such as... Figure 2 As shown:

[0063] S1: The input signal of the MCU processor is detected by at least one first detection circuit.

[0064] S2: Based on the detection result of the first detection circuit, the pressure difference caused by the first detection circuit is detected by the second detection circuit.

[0065] S3: Based on the pressure difference, perform pressure difference compensation to complete the consistent control of multiple input voltages.

[0066] The first detection circuit and the second detection circuit are connected at one end to a connector and at the other end to the MCU processor. The first detection circuit is used to detect the input signal to the MCU processor.

[0067] The second clamping circuit in this invention is used to eliminate the voltage difference caused by the leakage current of the first clamping circuit flowing through the second resistor and the third resistor.

[0068] As another preferred embodiment, the present invention also provides a device for detecting power supply and external interface signals, the device employing a multi-channel input voltage high-precision compensation circuit as described above.

[0069] Although exemplary embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above exemplary embodiments are merely illustrative and are not intended to limit the scope of the invention. Various changes and modifications can be made therein by those skilled in the art without departing from the scope and spirit of the invention. All such changes and modifications are intended to be included within the scope of the invention as claimed in the appended claims.

[0070] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0071] The various system and method embodiments of the present invention can be implemented in hardware, or as software modules running on one or more processors, or a combination thereof. Those skilled in the art will understand that microprocessors or digital signal processors (DSPs) can be used in practice to implement some or all of the functions of some modules according to embodiments of the present invention. The present invention can also be implemented as a system program (e.g., a computer program and computer program product) for performing part or all of the methods described herein. Such programs implementing the present invention can be stored on a computer-readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, provided on a carrier signal, or provided in any other form.

[0072] In the several embodiments provided in this application, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the system embodiments described above are merely illustrative. For instance, the division of functions is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple tools or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0073] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0074] Although the invention has been described in conjunction with the specific embodiments described above, it will be apparent to those skilled in the art that many substitutions, modifications, and variations can be made based on the foregoing. Therefore, all such substitutions, modifications, and variations are included within the spirit and scope of the appended claims.

Claims

1. A high-precision compensation circuit for multiple input voltages, characterized by, The compensation circuit includes at least a first detection circuit and a second detection circuit; one end of the first detection circuit and the second detection circuit are connected to a connector, and the other end is connected to an MCU processor. The first detection circuit is used to detect the input signal of the MCU processor; The second detection circuit is used to compensate for the voltage difference caused by at least one of the first detection circuits; The first detection circuit includes at least: a first clamping circuit, a first voltage divider circuit, a first noise filtering circuit, and a first anti-reverse component; one end of the first clamping circuit is connected to a first power supply, and the other end is connected to the first voltage divider circuit. The voltage is controlled within a preset range by the first voltage divider circuit, and after the noise is removed by the first noise filtering circuit, it is input to the MCU processor; the other end of the first voltage divider circuit is connected to a connector via the anti-reverse component. The first voltage divider circuit includes a first resistor, a second resistor, and a third resistor; one end of the first resistor is connected to the negative terminal of the first anti-reverse component, and the other end is connected to the first noise filtering circuit; the second resistor and the third resistor are connected in parallel with the first resistor; The second detection circuit includes at least: a second clamping circuit, a second voltage divider circuit, a second noise filtering circuit, and a second anti-reverse component; one end of the second clamping circuit is connected to a second power supply, and the other end is connected to the second voltage divider circuit; one end of the second voltage divider circuit is connected to a third power supply, and the other end is connected to the second noise filtering circuit and the second anti-reverse component respectively. The second voltage divider circuit is an equivalent resistance circuit, and the resistance of the second voltage divider circuit is equal to the resistance value of the first voltage divider circuit. The second clamping circuit is used to eliminate the voltage difference caused by the leakage current of the first clamping circuit flowing through the second resistor and the third resistor; The second noise filtering circuit includes a fifth resistor, a third capacitor, and a fourth capacitor; one end of the fifth resistor is connected to the equivalent resistance and the positive terminal of the second anti-reverse component, respectively; the third capacitor and the fourth capacitor are connected in parallel with the fifth resistor.

2. The high-precision compensation circuit for multiple input voltages according to claim 1, characterized in that, The first noise filtering circuit includes a fourth resistor, a first capacitor, and a second capacitor; one end of the fourth resistor is connected to the positive terminal of the first resistor and the first clamping circuit, respectively; the first capacitor and the second capacitor are connected in parallel with the fourth resistor.

3. A compensation method for a multi-channel input voltage high-precision compensation circuit according to any one of claims 1-2, Its features are, The compensation method includes the following steps: S1: The input signal to the MCU processor is detected by at least one first detection circuit; S2: Based on the detection result of the first detection circuit, the pressure difference caused by the first detection circuit is detected by the second detection circuit; S3: Based on the pressure difference, perform pressure difference compensation to complete the consistent control of multiple input voltages.

4. A high-precision compensation device for multi-channel input voltage, used for detecting power supply and external interface signals, characterized in that, The device employs a high-precision multi-input voltage compensation circuit as described in any one of claims 1-2.

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