Signal conditioning circuit, method and system

Abstract

This application provides a signal conditioning circuit, method, and system. The signal conditioning circuit includes: a signal conversion module having a first node and a second node, configured to select a conversion path corresponding to a control signal according to the control signal, and convert the input current of the first node into the output voltage of the second node based on the conversion path; a sensing module configured to provide input current to the first node; a reference voltage selection module configured to output a corresponding reference voltage according to the control signal; and a comparison module configured to output a preset control signal at an initial moment, and output a control signal for the next moment according to the relationship between the output voltage and the reference voltage. The signal conversion module includes multiple conversion paths, and the sensitivity of the output voltage obtained through different conversion paths varies. The technical solution provided by this application can adjust the sensitivity of the output voltage signal, thereby achieving wide-range light intensity detection.

Description

Technical Field

[0001] This application relates to the field of sensor signal conditioning technology, and in particular to a signal conditioning circuit, method and system. Background Technology

[0002] Photoelectric sensors based on organic photodiodes (OPDs) have shown great potential in the field of light intensity detection due to their unique advantages. These sensors are characterized by mechanical flexibility, ease of fabrication, tunable photoelectric properties, excellent light sensing performance, and biocompatibility, making them widely used in wearable devices and flexible electronic products.

[0003] However, adjusting the sensitivity of OPD-based photoelectric sensors remains challenging. This is especially true when achieving wide-range light intensity detection, as the relatively low photoelectric conversion efficiency of organic materials and their sensitivity to environmental factors limit their application in wide dynamic range light intensity detection. Therefore, existing OPD-based photoelectric sensors suffer from the drawback of not being able to achieve wide-range light intensity detection. Summary of the Invention

[0004] In view of this, the embodiments of this application aim to provide a signal conditioning circuit, method and system to solve the problem of difficulty in achieving large-area light intensity detection.

[0005] The first aspect of this application provides a signal conditioning circuit, comprising: a signal conversion module having a first node and a second node, configured to select a conversion path corresponding to the control signal according to the control signal, and convert the input current of the first node into the output voltage of the second node based on the conversion path; a sensing module configured to provide input current to the first node; a reference voltage selection module configured to output a corresponding reference voltage according to the control signal; and a comparison module configured to output a preset control signal at an initial moment, and output a control signal at the next moment according to the magnitude relationship between the output voltage and the reference voltage; wherein the signal conversion module includes multiple conversion paths, and the sensitivity of the output voltage obtained by the input current through different conversion paths is different.

[0006] In one embodiment, the multiple conversion paths include a first conversion path and a second conversion path; the signal conversion module further includes a selection unit and a first operational amplifier unit. The non-inverting input terminal of the first operational amplifier unit is grounded, the inverting input terminal of the first operational amplifier unit is connected to an input current, the positive power supply terminal of the first operational amplifier unit is connected to a first power supply voltage, the negative power supply terminal of the first operational amplifier unit is grounded, and the output terminal of the first operational amplifier unit outputs an output voltage. The first conversion path and the second conversion path are connected in parallel and connected in series with the selection unit between the first node and the second node. Preferably, the first conversion path includes a first resistor and a first capacitor connected in parallel, and the second conversion path includes a second resistor and a second capacitor connected in parallel.

[0007] In one embodiment, the selection unit includes a first switch, a second switch, a third switch, and a third resistor. The first terminal of the third resistor is connected to a second power supply voltage, the second terminal of the third resistor is connected to the first terminal of the first switch, the control terminal of the first switch is connected to a control signal, the second terminal of the first switch is grounded, the control terminal of the second switch is connected to the first terminal of the first switch, the first terminal of the second switch is connected to the second terminal of the first resistor and the second terminal of the first capacitor, the control terminal of the third switch is connected to a control signal, the first terminal of the third switch is connected to the second terminal of the second resistor and the second terminal of the second capacitor, and the second terminals of the second and third switches are connected to the output terminal of the first operational amplifier unit.

[0008] In one embodiment, the reference voltage selection module includes a fourth switch, a fifth switch, a sixth switch, and a fourth resistor. The first terminal of the fourth resistor is connected to a third power supply voltage, the second terminal of the fourth resistor is connected to the first terminal of the fourth switch, the control terminal of the fourth switch is connected to a control signal, and the second terminal of the fourth switch is grounded. The control terminal of the fifth switch is connected to the first terminal of the fourth switch, the first terminal of the fifth switch is connected to a first reference voltage, and the second terminal of the fifth switch is connected to a comparator module. The control terminal of the sixth switch is connected to a control signal, the first terminal of the sixth switch is connected to a second reference voltage, and the second terminal of the sixth switch is connected to a comparator module.

[0009] In one embodiment, the comparison module includes a second operational amplifier unit, the non-inverting input terminal of the second operational amplifier unit is connected to the output voltage, the inverting input terminal of the second operational amplifier unit is connected to the reference voltage, the positive power supply terminal of the second operational amplifier unit is connected to a fourth power supply voltage, the negative power supply terminal of the second operational amplifier unit is grounded, and the output terminal of the second operational amplifier unit outputs a control signal.

[0010] In one embodiment, the comparison module further includes a fifth resistor and a sixth resistor. The first end of the fifth resistor is connected to the positive power supply terminal of the second operational amplifier unit, the second end of the fifth resistor is connected to the output terminal of the second operational amplifier unit, the first end of the sixth resistor is connected to the non-inverting input terminal of the second operational amplifier unit, and the second end of the sixth resistor is connected to the output terminal of the second operational amplifier unit.

[0011] In one embodiment, the sensing module includes an organic photodiode.

[0012] In one embodiment, the signal conditioning circuit further includes an output module configured to filter the output voltage and output a detection voltage; the output module includes a seventh resistor and a third capacitor, the first end of the seventh resistor is connected to the output voltage, the second end of the seventh resistor outputs the detection voltage, the first end of the third capacitor is connected to the second end of the seventh resistor, and the second end of the third capacitor is grounded.

[0013] A second aspect of this application provides a signal conditioning method applicable to the signal conditioning circuit mentioned in any of the above embodiments. The signal conditioning method includes: A preset control signal is input to the signal conversion module, so that the signal conversion module selects the conversion path corresponding to the control signal and converts the input current of the first node into the output voltage of the second node based on the conversion path; wherein, the signal conversion module includes multiple conversion paths, and the sensitivity of the output voltage obtained by the input current through different conversion paths is different; a control signal is input to the reference voltage selection module, so that the reference selection module outputs the corresponding reference voltage according to the control signal; the output voltage and the reference voltage are input to the comparison module, so that the comparison module outputs the control signal for the next moment according to the relationship between the magnitude of the output voltage and the reference voltage.

[0014] A third aspect of this application provides a signal conditioning system, including: a signal conditioning circuit as mentioned in any of the above embodiments.

[0015] The technical solution provided in this application sets multiple conversion paths in the signal conversion module. By adjusting the conversion paths, the sensitivity of the output voltage can be changed, enabling the circuit to adapt to the detection requirements of different light intensity ranges. By setting a comparison module to compare the output voltage and the reference voltage, controlling the reference voltage selection module to adjust the reference voltage in real time, and controlling the signal conversion module to adjust the conversion path, the output voltage can be ensured to always be within the optimal detection range, thereby improving the accuracy of light intensity detection. Therefore, the technical solution provided in this application can adjust the sensitivity of the output voltage signal, thereby achieving wide-range light intensity detection.

[0016] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 The diagram shown is a schematic diagram of a signal conditioning circuit provided in an embodiment of this application.

[0019] Figure 2 The diagram shown is a schematic diagram of a signal conditioning circuit provided in another embodiment of this application.

[0020] Figure 3The diagram shown is a structural schematic of a signal conditioning circuit provided in another embodiment of this application.

[0021] Figure 4 The diagram shown is a structural schematic of a signal conditioning circuit provided in another embodiment of this application.

[0022] Figure 5 The diagram shown is a structural schematic of a signal conditioning circuit provided in another embodiment of this application.

[0023] Figure 6 The diagram shown is a structural schematic of a signal conditioning circuit provided in another embodiment of this application.

[0024] Figure 7 The diagram shown is a structural schematic of a signal conditioning circuit provided in another embodiment of this application.

[0025] Figure 8 The diagram shown is a simulation circuit structure diagram of a signal conditioning circuit provided in an embodiment of this application.

[0026] Figure 9 The figure shown is a simulation waveform diagram of a signal conditioning circuit provided in an embodiment of this application.

[0027] Figure 10 The diagram shown is a simulation waveform of a signal conditioning circuit provided in another embodiment of this application.

[0028] Figure 11 The diagram shown is a simulation waveform of a signal conditioning circuit provided in another embodiment of this application.

[0029] Figure 12 The diagram shown is a simulation waveform of a signal conditioning circuit provided in another embodiment of this application.

[0030] Figure 13 The diagram shown is a schematic flowchart of a signal conditioning method provided in an embodiment of this application. Detailed Implementation

[0031] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0032] Figure 1 The diagram shown is a structural schematic of a signal conditioning circuit provided in an embodiment of this application. Figure 1As shown, the signal conditioning circuit includes: a signal conversion module 101, having a first node N1 and a second node N2, configured to select a conversion path corresponding to the control signal VSW according to the control signal VSW, and convert the input current of the first node N1 into the output voltage of the second node N2 based on the conversion path; a sensing module 102, configured to provide input current to the first node N1; a reference voltage selection module 103, configured to output a corresponding reference voltage according to the control signal VSW; and a comparison module 104, configured to output a preset control signal at an initial moment, and output the control signal VSW at the next moment according to the relationship between the output voltage and the reference voltage; wherein, the signal conversion module 101 includes multiple conversion paths, and the sensitivity of the output voltage obtained by the input current through different conversion paths is different.

[0033] Specifically, the signal conversion module 101 includes a first node N1 and a second node N2. The first node N1 receives the input current of the sensing module 102, and the second node N2 outputs a voltage. For example, the input current of the sensing module 102 is proportional to the light intensity to be detected. Multiple conversion paths in the signal conversion module 101 can be selected according to the control signal VSW. Different conversion paths correspond to different output voltage sensitivities, thereby adjusting the sensitivity of the output voltage during the conversion from input current to output voltage. The reference voltage selection module 103 outputs a corresponding reference voltage according to the control signal VSW, providing a benchmark for the comparison module 104. The comparison module 104 compares the magnitude of the output voltage and the reference voltage and outputs a corresponding control signal VSW, which can be used to adjust the conversion paths of the signal conversion module 101. Because the sensitivity of the output voltage can be adjusted, a wide range of light intensity detection can be achieved. When the light intensity is weak, a high-sensitivity conversion path is selected; when the light intensity is strong, a low-sensitivity conversion path is selected. In this way, high detection accuracy can be maintained throughout the entire light intensity range.

[0034] For example, the signal conditioning circuit operates as follows: When an external light source illuminates the sensing module 102, the sensing module 102 converts the received light signal into a current signal and outputs it. The current signal output by the sensing module 102 flows into the signal conversion module 101 via the first node N1. The comparison module 104 outputs a preset control signal. Under the control of this preset control signal, the signal conversion module 101 converts the input current into a voltage signal and outputs it at the second node N2. Next, the comparison module 104 receives the output voltage of the signal conversion module 101, compares it with a reference voltage, and outputs a control signal VSW for the next moment based on the comparison result. This control signal VSW is input to the signal conversion module 101 to select the conversion path. The control signal VSW is also input to the reference voltage selection module 103 to select the reference voltage.

[0035] For example, when the comparison module 104 is first powered on, it outputs 0 as a preset control signal. At this time, the signal conditioning circuit operates in a high-sensitivity state.

[0036] The technical solution of this embodiment sets multiple conversion paths in the signal conversion module 101. By adjusting the conversion paths, the sensitivity of the output voltage can be changed, enabling the circuit to adapt to the detection requirements of different light intensity ranges. By setting a comparison module 104 to compare the output voltage and the reference voltage, controlling the reference voltage selection module 103 to adjust the reference voltage in real time, and controlling the signal VSW conversion module 101 to adjust the conversion path, it can be ensured that the output voltage is always within the optimal detection range, thereby improving the accuracy of light intensity detection. Therefore, the technical solution provided in this embodiment can adjust the sensitivity of the output voltage signal, thereby achieving wide-range light intensity detection.

[0037] Figure 2 The diagram shown is a structural schematic of a signal conditioning circuit provided in another embodiment of this application. Figure 2 As shown, the multiple conversion paths include a first conversion path and a second conversion path; the signal conversion module 101 also includes a selection unit 1011 and a first operational amplifier unit U1. The non-inverting input terminal of the first operational amplifier unit U1 is grounded, the inverting input terminal of the first operational amplifier unit U1 is connected to the input current, the positive power supply terminal of the first operational amplifier unit U1 is connected to the first power supply voltage VCC1, the negative power supply terminal of the first operational amplifier unit U1 is grounded, and the output terminal of the first operational amplifier unit U1 outputs the output voltage. The first conversion path and the second conversion path are connected in parallel and connected in series with the selection unit 1011 between the first node N1 and the second node N2. Preferably, the first conversion path includes a first resistor R1 and a first capacitor C1 connected in parallel, and the second conversion path includes a second resistor R2 and a second capacitor C2 connected in parallel.

[0038] Specifically, the first operational amplifier unit U1 is disposed between the first node N1 and the second node N2, and multiple conversion paths are disposed between the inverting input and output terminals of the first operational amplifier unit U1. The first conversion path and the second conversion path are connected in parallel and both are connected in series with the selection unit 1011, so that the selection unit 1011 selects the first conversion path or the second conversion path to be turned on according to the control signal VSW. For example, the selection unit 1011 can be a switch, a multiplexer, or other similar electronic selection element. The first operational amplifier unit U1 is used to amplify the input current and convert it into an output voltage signal. For example, the first operational amplifier unit U1 can use an operational amplifier chip of model OPA340. Using this chip as the first operational amplifier unit U1 can effectively process the weak signal output by the sensing module 102, improve the signal stability and anti-interference ability, and, combined with adjusting the conversion path, can realize the adjustment of the output voltage sensitivity, thereby realizing a wide range of light intensity detection. The non-inverting input terminal of the operational amplifier chip is grounded, the inverting input terminal is connected to the input current, the positive power supply terminal is connected to the first power supply voltage VCC1, the negative power supply terminal is grounded, and the output terminal outputs the voltage.

[0039] Preferably, the first resistor R1 and the first capacitor C1 are connected in parallel to form a first conversion path; the second resistor R2 and the second capacitor C2 are connected in parallel to form a second conversion path. The resistance values ​​of the first resistor R1 and the second resistor R2 are not equal, and the capacitance values ​​of the first capacitor C1 and the second capacitor C2 are also not equal. For example, the resistance value of the first resistor R1 is 40kΩ±5%, the capacitance value of the first capacitor C1 is 2pF±5%, the resistance value of the second resistor R2 is 80kΩ±5%, and the capacitance value of the second capacitor C2 is 4pF±5%. When the selection unit 1011 is connected to the first conversion path, the sensitivity of the output voltage is low, and the signal conditioning circuit is suitable for detection environments with high light intensity. When the selection unit 1011 is connected to the second conversion path, the sensitivity of the output voltage is high, and the signal conditioning circuit is suitable for detection environments with low light intensity.

[0040] In this embodiment, by setting a first operational amplifier unit U1 and multiple conversion paths in the signal conversion module 101, the input current is converted into a sensitive output voltage, improving signal stability and anti-interference capability. Furthermore, by setting parallel resistors and capacitors to form the conversion paths, the signal conditioning circuit structure is simple and easy to implement, further facilitating the realization of wide-range light intensity detection.

[0041] Figure 3 The diagram shown is a structural schematic of a signal conditioning circuit provided in another embodiment of this application. Figure 3As shown, the selection unit 1011 includes a first switch T1, a second switch T2, a third switch T3, and a third resistor R3. The first terminal of the third resistor R3 is connected to the second power supply voltage VCC2, and the second terminal of the third resistor R3 is connected to the first terminal of the first switch T1. The control terminal of the first switch T1 is connected to the control signal VSW, and the second terminal of the first switch T1 is grounded. The control terminal of the second switch T2 is connected to the first terminal of the first switch T1, and the first terminal of the second switch T2 is connected to the second terminal of the first resistor R1 and the second terminal of the first capacitor C1. The control terminal of the third switch T3 is connected to the control signal VSW, and the first terminal of the third switch T3 is connected to the second terminal of the second resistor R2 and the second terminal of the second capacitor C2. The second terminals of the second switch T2 and the second terminals of the third switch T3 are connected to the output terminal of the first operational amplifier unit U1.

[0042] Specifically, in selection unit 1011, the control terminal of the first switching transistor T1 is connected to the control signal VSW, the control terminal of the second switching transistor T2 is connected to the first terminal of the first switching transistor T1, the first terminal of the second switching transistor T2 is connected to the common terminal of the first resistor R1 and the first capacitor C1 (i.e., the first terminal of the second switching transistor T2 is connected to the first switching path), and the second terminal of the second switching transistor T2 is connected to the output terminal of the first operational amplifier unit U1. When the first switching transistor T1 is turned on, the second switching transistor T2 is also turned on, thus enabling the first switching path. The control terminal of the third switching transistor T3 is connected to the control signal VSW, its first terminal is connected to the common terminal of the second resistor R2 and the second capacitor C2 (i.e., the first terminal of the third switching transistor T3 is connected to the second switching path), and its second terminal is connected to the output terminal of the first operational amplifier unit U1. When the third switching transistor T3 is turned on, the second switching path is enabled.

[0043] See Figure 3 For example, the first switch T1 can be an N-type switch, the second switch T2 can be a P-type switch, and the third switch T3 can be a P-type switch. For example, when the control signal VSW is high, the first switch T1 is turned on, and the first terminal voltage of the first switch T1 is pulled down, causing the second switch T2 to turn on and the third switch T3 to turn off, thus enabling selection unit 1011 and the first switching path. When the control signal VSW is low, the third switch T3 is turned on, and the first switch T1 and the second switch T2 are turned off, thus enabling selection unit 1011 and the second switching path. For example, the first switch T1 can be a 2N6763 switch, and the second and third switches T2 can be IRF9130 switches.

[0044] The selection unit 1011 also includes a third resistor R3, whose first terminal is connected to the second power supply voltage VCC2, and whose second terminal is connected to the first terminal of the first switching transistor T1, for providing an appropriate bias voltage to the first switching transistor T1. For example, the resistance value of the third resistor R3 can be set to 10kΩ ± 5%.

[0045] In this embodiment, by controlling the on / off states of the first switch T1, the second switch T2, and the third switch T3, the selection unit 1011 can select to conduct either the first switching path or the second switching path, thereby adjusting the output voltage sensitivity and further facilitating wide-range light intensity detection. By setting the third resistor R3, current limiting and voltage division can be achieved, preventing instantaneous current surges from damaging the first switch T1, reducing voltage stress on the first switch T1, and improving the stability and reliability of its operation.

[0046] Figure 4 The diagram shown is a structural schematic of a signal conditioning circuit provided in another embodiment of this application. Figure 4 As shown, the reference voltage selection module 103 includes a fourth switch T4, a fifth switch T5, a sixth switch T6, and a fourth resistor R4. The first terminal of the fourth resistor R4 is connected to the third power supply voltage VCC3, and the second terminal of the fourth resistor R4 is connected to the first terminal of the fourth switch T4. The control terminal of the fourth switch T4 is connected to the control signal VSW, and the second terminal of the fourth switch T4 is grounded. The control terminal of the fifth switch T5 is connected to the first terminal of the fourth switch T4, and the first terminal of the fifth switch T5 is connected to the first reference voltage Vref1. The second terminal of the fifth switch T5 is connected to the comparator module 104. The control terminal of the sixth switch T6 is connected to the control signal VSW, and the first terminal of the sixth switch T6 is connected to the second reference voltage Vref2. The second terminal of the sixth switch T6 is connected to the comparator module 104.

[0047] Specifically, in the reference voltage selection module 103, the control terminal of the fourth switch T4 is connected to the control signal VSW, the control terminal of the fifth switch T5 is connected to the first terminal of the fourth switch T4, the first terminal of the fifth switch T5 is connected to the first reference voltage Vref1, and the second terminal of the fifth switch T5 is connected to the comparator module 104. When the fourth switch T4 is turned on, the fifth switch T5 is also turned on, and the first reference voltage Vref1 is output to the comparator module 104. The control terminal of the sixth switch T6 is connected to the control signal VSW, its first terminal is connected to the second reference voltage Vref2, and its second terminal is connected to the comparator module 104. When the sixth switch T6 is turned on, the second reference voltage Vref2 is output to the comparator module 104.

[0048] See Figure 4For example, the fourth switch T4 can be an N-type switch, the fifth switch T5 can be a P-type switch, and the sixth switch T6 can be a P-type switch. For example, when the control signal VSW is high, the fourth switch T4 is turned on, and the voltage at its first terminal is pulled down, causing the fifth switch T5 to turn on and the sixth switch T6 to turn off. Then, the reference voltage selection module 103 outputs the first reference voltage Vref1 to the comparison module 104. When the control signal VSW is low, the sixth switch T6 is turned on, and the fourth and fifth switches T4 are turned off. Then, the reference voltage selection module 103 outputs the second reference voltage Vref2 to the comparison module 104. For example, the fourth switch T4 can be a 2N6763 switch, and the fifth and sixth switches T5 can be IRF9130 switches. For example, the first reference voltage Vref1 can be set to 2V, and the second reference voltage Vref2 can be set to 4V.

[0049] A fourth resistor R4 is also provided in the reference voltage selection module 103. Its first terminal is connected to the third power supply voltage VCC3, and its second terminal is connected to the first terminal of the fourth switching transistor T4, for providing an appropriate bias voltage to the fourth switching transistor T4. For example, the resistance value of the fourth resistor R4 can be set to 10kΩ±5%.

[0050] In this embodiment, by controlling the on / off states of the fourth switch T4, the fifth switch T5, and the sixth switch T6, the reference voltage selection module 103 can select either the first reference voltage Vref1 or the second reference voltage Vref2 to output to the comparison module 104. By switching the reference voltage, the sensitivity and detection range of the output voltage can be adjusted, further facilitating the realization of wide-range light intensity detection. The fourth resistor R4 serves to limit current and divide voltage, preventing instantaneous current surges from damaging the fourth switch T4, reducing voltage stress on the fourth switch T4, and improving the stability and reliability of its operation.

[0051] Figure 5 The diagram shown is a structural schematic of a signal conditioning circuit provided in another embodiment of this application. Figure 5 As shown, the comparison module 104 includes a second operational amplifier unit U2, the non-inverting input terminal of the second operational amplifier unit U2 is connected to the output voltage, the inverting input terminal of the second operational amplifier unit U2 is connected to the reference voltage, the positive power supply terminal of the second operational amplifier unit U2 is connected to the fourth power supply voltage VCC4, the negative power supply terminal of the second operational amplifier unit U2 is grounded, and the output terminal of the second operational amplifier unit U2 outputs the control signal VSW.

[0052] Specifically, the second operational amplifier unit U2 compares the output voltage and the reference voltage and outputs a corresponding control signal VSW. This control signal VSW changes in real time based on the comparison result. For example, when the output voltage is less than the reference voltage, the second operational amplifier unit U2 outputs a low-level control signal VSW; when the output voltage is greater than or equal to the reference voltage, the second operational amplifier unit U2 outputs a high-level control signal VSW. This control signal VSW can be directly used in the selection unit 1011 of the control signal VSW conversion module 101 and the reference voltage selection module 103 to dynamically adjust the conversion path and reference voltage to adapt to different light intensity detection requirements.

[0053] The positive power supply terminal of the second operational amplifier unit U2 is connected to the fourth power supply voltage VCC4, and the negative power supply terminal is grounded, providing the power required for the operation of the second operational amplifier unit U2. For example, the second operational amplifier unit U2 can use an operational amplifier chip of model LMC7211A. Using this chip as the second operational amplifier unit U2, by connecting the output voltage and the reference voltage to the non-inverting input terminal and the inverting input terminal of the second operational amplifier unit U2 respectively, the comparison module 104 can accurately and quickly compare the magnitudes of the two voltages, adjust the conversion path in real time, and realize the adjustment of the output voltage sensitivity, thereby achieving wide-range light intensity detection.

[0054] In this embodiment, a second operational amplifier unit U2 is provided in the comparison module 104 to output a corresponding control signal VSW by comparing the magnitude relationship between the output voltage and the reference voltage. On the one hand, the second operational amplifier unit U2 has high gain and low bias current, enabling the comparison module 104 to achieve accurate voltage comparison, thereby generating an accurate control signal VSW and improving the system's adjustment accuracy. On the other hand, it simplifies the signal conditioning circuit structure and makes it easy to implement, further facilitating the realization of wide-range light intensity detection.

[0055] Figure 6 The diagram shown is a structural schematic of a signal conditioning circuit provided in another embodiment of this application. Figure 6 As shown, the comparison module 104 also includes a fifth resistor R5 and a sixth resistor R6. The first end of the fifth resistor R5 is connected to the positive power supply terminal of the second operational amplifier unit U2, the second end of the fifth resistor R5 is connected to the output terminal of the second operational amplifier unit U2, the first end of the sixth resistor R6 is connected to the non-inverting input terminal of the second operational amplifier unit U2, and the second end of the sixth resistor R6 is connected to the output terminal of the second operational amplifier unit U2.

[0056] Specifically, the fifth resistor R5 is connected between the positive power supply terminal and the output terminal of the second operational amplifier unit U2, acting as a pull-up resistor to ensure that the output terminal of the second operational amplifier unit U2 outputs a high-level control signal VSW when the circuit starts up. The sixth resistor R6 is connected between the non-inverting input terminal and the output terminal of the second operational amplifier unit U2, forming a positive feedback loop, which can reduce the time required for the output terminal to switch from one state to another, thus speeding up the response speed of the second operational amplifier unit U2.

[0057] For example, the resistance of the fifth resistor R5 can be set to 10kΩ±5%, and the resistance of the sixth resistor R6 can be set to 10kΩ±5%.

[0058] In this embodiment, the output level of the second operational amplifier unit U2 when the circuit is started is defined by setting the fifth resistor R5, and the response speed of the second operational amplifier unit U2 is accelerated by setting the sixth resistor R6, which improves the reliability of the signal conditioning circuit, further facilitates the adjustment of the sensitivity of the output voltage, and further facilitates the realization of wide-range light intensity detection.

[0059] Figure 7 The diagram shown is a structural schematic of a signal conditioning circuit provided in another embodiment of this application. Figure 7 As shown, the signal conditioning circuit also includes an output module, configured to filter the output voltage and output a detection voltage; the output module includes a seventh resistor R7 and a third capacitor C3, the first end of the seventh resistor R7 is connected to the output voltage, the second end of the seventh resistor R7 outputs the detection voltage, the first end of the third capacitor C3 is connected to the second end of the seventh resistor R7, and the second end of the third capacitor C3 is grounded.

[0060] Specifically, the output module filters the output voltage, and the filtered detected voltage is output to subsequent circuits, such as an analog-to-digital converter. A seventh resistor R7 is connected to the output of the first operational amplifier unit U1. This serves two purposes: firstly, it, together with the third capacitor C3, forms a low-pass filter to filter the output voltage; secondly, it limits current and protects the circuit. The first terminal of the third capacitor C3 is connected to the second terminal of the seventh resistor R7, and the second terminal is grounded. This connection method allows the low-pass filter to effectively guide high-frequency components to ground, while only allowing low-frequency components to pass through.

[0061] For example, the resistance of the seventh resistor R7 can be set to 10Ω ±5%, and the capacitance of the third capacitor C3 can be set to 1μF ±5%.

[0062] In this embodiment, the output module is configured to filter out high-frequency noise and ripple in the output voltage, making the output detection voltage signal smoother and improving the accuracy and reliability of the signal.

[0063] In one embodiment, the sensing module 102 includes an organic photodiode.

[0064] Specifically, an organic photodiode is a photoelectric conversion device based on organic semiconductors that converts light signals into electrical signals. Organic photodiodes generate electron-hole pairs by absorbing photons; these charge carriers separate under the influence of an electric field, forming a current. Therefore, by detecting the current flowing through an organic photodiode, light intensity can be indirectly measured.

[0065] In this embodiment, the advantages of using an organic photodiode as the light intensity detection element in the sensing module 102 are as follows: Organic photodiodes have a high light absorption coefficient and good photoelectric conversion efficiency, making them very sensitive to changes in light intensity and suitable for light intensity detection; organic materials can be fabricated into thin films, so the sensing module 102 made of organic photodiodes is thin and lightweight, facilitating integration and miniaturization; organic materials have good flexibility, allowing for the fabrication of a bendable sensing module 102, suitable for non-planar or dynamically changing detection environments; organic photodiodes can be designed to be sensitive to different wavelength ranges as needed, thus adapting to different application scenarios.

[0066] Figure 8 The diagram shown is a simulation circuit structure diagram of a signal conditioning circuit provided in an embodiment of this application. Figure 8 As shown, this application provides an equivalent circuit structure for a sensing module 102. This equivalent circuit includes a unidirectional conducting element D, a current source IS, an eighth resistor R8, and a fourth capacitor C4 connected in parallel. The first terminals of the unidirectional conducting element D, the current source IS, the eighth resistor R8, and the fourth capacitor C4 are connected to a bias voltage signal VBIAS_N. The second terminals of the unidirectional conducting element D, the current source IS, the eighth resistor R8, and the fourth capacitor C4 are connected to a signal conversion module 101. This equivalent circuit structure can be used to simulate the performance of the sensing module 102 in a real circuit system.

[0067] Figure 9 The image shown is a simulation waveform diagram of a signal conditioning circuit provided in an embodiment of this application. Figure 9 As shown, the second channel IG1 is the simulated input excitation current. When the input current (first channel AM1) is 5uA, the output voltage (third channel Vout) is 0.439V, the reference voltage (fourth channel Vref) is 4V, the control signal VSW (fifth channel Vsw) is 1.69mV, and the control signal VSW is at a low level. At this time, the sensitivity of the output voltage is relatively high, and the range of the sensing module 102 is relatively small.

[0068] Figure 10 The diagram shown is a simulation waveform of a signal conditioning circuit provided in another embodiment of this application. Figure 10As shown, the second channel IG1 is the simulated input excitation current. When the input current (first channel AM1) is 45uA, the output voltage (third channel Vout) is 3.6V, the reference voltage (fourth channel Vref) is 4V, the control signal VSW (fifth channel Vsw) is 13.3mV, and the control signal VSW is at a low level. At this time, the sensitivity of the output voltage is relatively high, and the output voltage is close to saturation.

[0069] Figure 11 The diagram shown is a simulation waveform of a signal conditioning circuit provided in another embodiment of this application. Figure 11 As shown, the second channel IG1 is the simulated input excitation current. When the input current (first channel AM1) is 55uA, the output voltage (third channel Vout) is 2.2V, the reference voltage (fourth channel Vref) is 2V, the control signal VSW (fifth channel Vsw) is 5V, and the control signal VSW is at a high level. At this time, the sensitivity of the output voltage is relatively low, and the range of the sensing module 102 is relatively large.

[0070] Figure 12 The image shown is a simulation waveform diagram of a signal conditioning circuit provided in another embodiment of this application. Figure 12 As shown, the second channel IG1 is the simulated input excitation current. When the input current (first channel AM1) is 120uA, the output voltage (third channel Vout) is 4.8V, the reference voltage (fourth channel Vref) is 2V, the control signal VSW (fifth channel Vsw) is 5V, and the control signal VSW is at a high level. At this time, the sensitivity of the output voltage is low, and the output voltage has saturated.

[0071] The above simulation results demonstrate that the signal conditioning circuit provided in this application embodiment can adjust the sensitivity of the output signal, thereby achieving wide-range light intensity detection.

[0072] Figure 13 The diagram shown is a schematic flowchart of a signal conditioning method provided in an embodiment of this application. This method is applicable to the signal conditioning circuits mentioned in any of the above embodiments. Figure 13 As shown, the signal conditioning method includes: S110: A preset control signal is input to the signal conversion module, so that the signal conversion module selects a conversion path corresponding to the control signal, and converts the input current of the first node into the output voltage of the second node based on the conversion path. The signal conversion module includes multiple conversion paths, and the sensitivity of the output voltage obtained by the input current through different conversion paths varies.

[0073] Specifically, a preset control signal is input to the signal conversion module, and the conversion path corresponding to the control signal is selected. The signal conversion module converts the input current into a voltage signal through the conversion path and outputs it at the second node.

[0074] S120, input a control signal to the reference voltage selection module so that the reference selection module outputs the corresponding reference voltage according to the control signal.

[0075] Specifically, a control signal is input to the reference voltage selection module, and the reference voltage selection module outputs a corresponding reference voltage to the comparison module according to the level state of the control signal, which serves as the reference voltage for the comparison module.

[0076] S130: Input the output voltage and reference voltage to the comparison module so that the comparison module outputs the control signal for the next moment based on the relationship between the magnitude of the output voltage and the reference voltage.

[0077] Specifically, the comparison module receives the output voltage and a reference voltage as input. The comparison module compares the output voltage with the reference voltage and outputs a control signal based on the comparison result. For example, if the output voltage is less than the reference voltage, the comparison module outputs a low-level control signal; if the output voltage is greater than or equal to the reference voltage, the comparison module outputs a high-level control signal.

[0078] The technical solution of this embodiment achieves closed-loop control of the signal conditioning circuit by inputting a control signal to the signal conversion module, enabling the signal conversion module to select a conversion path corresponding to the control signal; inputting a control signal to the reference voltage selection module, enabling the reference selection module to output a corresponding reference voltage; and inputting the output voltage and reference voltage to the comparison module, enabling the comparison module to output a control signal based on the magnitude relationship between the output voltage and the reference voltage. By adjusting the conversion path and reference voltage, the sensitivity of the output voltage can be changed, allowing the circuit to adapt to the detection requirements of different light intensity ranges. Therefore, the technical solution provided in this embodiment can adjust the sensitivity of the output voltage signal, thereby achieving wide-range light intensity detection.

[0079] This application also provides a signal conditioning system, including a signal conditioning circuit as mentioned in any of the above embodiments. This signal conditioning system has the beneficial effects of the signal conditioning circuit mentioned in any of the above embodiments, and its technical principles and effects are similar, so they will not be described again here.

[0080] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this application can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this application can be achieved, and this is not limited herein.

[0081] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A signal conditioning circuit, characterized in that, include: The signal conversion module has a first node and a second node, and is configured to select a conversion path corresponding to the control signal according to the control signal, and convert the input current of the first node into the output voltage of the second node based on the conversion path; The sensing module is configured to provide the input current to the first node; The reference voltage selection module is configured to output a corresponding reference voltage according to the control signal. The comparison module is configured to output a preset control signal at an initial moment, and to output the control signal at the next moment based on the relationship between the output voltage and the reference voltage. The signal conversion module includes multiple conversion paths, and the sensitivity of the output voltage obtained by the input current through different conversion paths is different.

2. The signal conditioning circuit according to claim 1, characterized in that, The multiple conversion paths include a first conversion path and a second conversion path; the signal conversion module further includes a selection unit and a first operational amplifier unit. The non-inverting input terminal of the first operational amplifier unit is grounded, the inverting input terminal of the first operational amplifier unit is connected to the input current, the positive power supply terminal of the first operational amplifier unit is connected to a first power supply voltage, the negative power supply terminal of the first operational amplifier unit is grounded, and the output terminal of the first operational amplifier unit outputs the output voltage. The first conversion path and the second conversion path are connected in parallel and connected in series with the selection unit between the first node and the second node. Preferably, the first conversion path includes a first resistor and a first capacitor connected in parallel, and the second conversion path includes a second resistor and a second capacitor connected in parallel.

3. The signal conditioning circuit according to claim 2, characterized in that, The selection unit includes a first switch, a second switch, a third switch, and a third resistor. The first terminal of the third resistor is connected to a second power supply voltage. The second terminal of the third resistor is connected to the first terminal of the first switch. The control terminal of the first switch is connected to the control signal. The second terminal of the first switch is grounded. The control terminal of the second switch is connected to the first terminal of the first switch. The first terminal of the second switch is connected to the second terminal of the first resistor and the second terminal of the first capacitor. The control terminal of the third switch is connected to the control signal. The first terminal of the third switch is connected to the second terminal of the second resistor and the second terminal of the second capacitor. The second terminals of the second switch and the second terminals of the third switch are connected to the output terminal of the first operational amplifier unit.

4. The signal conditioning circuit according to claim 1, characterized in that, The reference voltage selection module includes a fourth switch, a fifth switch, a sixth switch, and a fourth resistor. The first terminal of the fourth resistor is connected to a third power supply voltage, the second terminal of the fourth resistor is connected to the first terminal of the fourth switch, the control terminal of the fourth switch is connected to the control signal, and the second terminal of the fourth switch is grounded. The control terminal of the fifth switch is connected to the first terminal of the fourth switch, the first terminal of the fifth switch is connected to a first reference voltage, and the second terminal of the fifth switch is connected to the comparison module. The control terminal of the sixth switch is connected to the control signal, the first terminal of the sixth switch is connected to a second reference voltage, and the second terminal of the sixth switch is connected to the comparison module.

5. The signal conditioning circuit according to claim 1, characterized in that, The comparison module includes a second operational amplifier unit, the non-inverting input terminal of the second operational amplifier unit is connected to the output voltage, the inverting input terminal of the second operational amplifier unit is connected to the reference voltage, the positive power supply terminal of the second operational amplifier unit is connected to a fourth power supply voltage, the negative power supply terminal of the second operational amplifier unit is grounded, and the output terminal of the second operational amplifier unit outputs the control signal.

6. The signal conditioning circuit according to claim 5, characterized in that, The comparison module further includes a fifth resistor and a sixth resistor. The first end of the fifth resistor is connected to the positive power supply terminal of the second operational amplifier unit, the second end of the fifth resistor is connected to the output terminal of the second operational amplifier unit, the first end of the sixth resistor is connected to the non-inverting input terminal of the second operational amplifier unit, and the second end of the sixth resistor is connected to the output terminal of the second operational amplifier unit.

7. The signal conditioning circuit according to claim 1, characterized in that, The sensing module includes an organic photodiode.

8. The signal conditioning circuit according to claim 1, characterized in that, It also includes an output module configured to filter the output voltage and output a detection voltage; the output module includes a seventh resistor and a third capacitor, the first end of the seventh resistor is connected to the output voltage, the second end of the seventh resistor outputs the detection voltage, the first end of the third capacitor is connected to the second end of the seventh resistor, and the second end of the third capacitor is grounded.

9. A signal conditioning method, characterized in that, The signal conditioning circuit applicable to any one of claims 1-8, the signal conditioning method comprising: A preset control signal is input to the signal conversion module so that the signal conversion module selects a conversion path corresponding to the control signal and converts the input current of the first node into the output voltage of the second node based on the conversion path; wherein, the signal conversion module includes multiple conversion paths, and the sensitivity of the output voltage obtained by the input current through different conversion paths is different; The control signal is input to the reference voltage selection module so that the reference selection module outputs the corresponding reference voltage according to the control signal; The output voltage and the reference voltage are input to the comparison module so that the comparison module outputs the control signal for the next moment based on the relationship between the magnitude of the output voltage and the reference voltage.

10. A signal conditioning system, characterized in that, include: The signal conditioning circuit as described in any one of claims 1 to 8.

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