Double-end output circuit based on single-end signal source and signal processing circuit

Abstract

The present invention provides a double-ended output circuit and a signal processing circuit based on a single-ended signal source, in which the signal processing circuit based on the single-ended signal source is configured to amplify an original signal in a single-ended signal form output by the single-ended signal source with an instrumentation amplifier (In-Amp), so as to utilize the high input impedance of the instrumentation amplifier and improve the signal processing efficiency. Complete and high-precision amplification processing is carried out on an original signal in a single-ended signal form output by the single-ended signal source by virtue of the native advantages of high common-mode rejection ratio, high gain adjustment precision, low temperature drift, good linearity and low noise; therefore, weak signals in original signals output by the single-ended signal source can be effectively captured, and the reliability of a corresponding sensing device adopting the signal processing circuit based on the single-ended signal source is guaranteed correspondingly when the single-ended signal source is a corresponding sensing device.

Description

Technical Field

[0001] This invention relates to the field of signal processing, and more specifically to a dual-ended output circuit and a signal processing circuit based on a single-ended signal source. Background Technology

[0002] With the development of IoT technology and the popularization of low-carbon and environmentally friendly concepts, artificial intelligence, smart home, and smart security technologies are increasingly demanding environmental detection, especially the detection of moving objects (such as people or vehicles). This allows for intelligent control of electrical equipment based on detection results, such as controlling lighting status based on the presence or absence of a human to achieve intelligent, low-carbon lighting. Passive infrared detection technology (primarily targeting the human body), ultrasonic detection technology, and microwave detection technology based on the Doppler effect are three commonly used and relatively mature technologies for detecting moving objects. While each of these technologies has its advantages and disadvantages, they all struggle to balance detection sensitivity and accuracy, and generally suffer from inconsistent reliability across different scenarios.

[0003] Taking the most commonly used passive infrared detection technology as an example, the corresponding infrared detection device includes a pyroelectric infrared sensor and a Fresnel lens disposed in the light-sensing path of the pyroelectric infrared sensor. The Fresnel lens is a lens array composed of multiple lens units, and each lens unit has the light-gathering characteristic of a convex lens. An example is a binary pyroelectric infrared sensor, which includes a positive temperature-sensing surface and a negative temperature-sensing surface arranged side-by-side. The positive temperature-sensing surface forms a temperature-sensing space defined as a bright area through any lens unit, and the negative temperature-sensing surface forms a temperature-sensing space defined as a dark area through the same lens unit. A blind area also exists between the bright and dark areas. That is, the pyroelectric infrared sensor can form a corresponding number of bright and dark areas through the lens array of the Fresnel lens, as well as areas defined in the bright area... The blind zone between the bright and dark zones corresponds to the infrared light emitted by a human body in the bright zone as an infrared radiator, which can be focused by a corresponding lens unit onto the positive temperature-sensing surface, generating a positive voltage on the positive temperature-sensing surface. Similarly, the infrared light emitted by a human body in the dark zone as an infrared radiator can be focused by a corresponding lens unit onto the negative temperature-sensing surface, generating a negative voltage on the negative temperature-sensing surface. Thus, when a human body moves across any two zones (bright, dark, or blind), the infrared spot corresponding to the human body enters or leaves the corresponding temperature-sensing surface, creating a voltage difference change between the positive and negative temperature-sensing surfaces. The pyroelectric infrared sensor outputs an electrical signal (single-ended signal) corresponding to the voltage difference change between the positive and negative temperature-sensing surfaces, allowing the infrared detection device to detect the human body's cross-zone movement based on the corresponding change in this electrical signal. According to the above-described working principle of the infrared detection device, on the one hand, the voltage change on the positive and negative temperature-sensing surfaces is related to the temperature difference between the human body (as an infrared radiator) and the environment, and is therefore affected by the ambient temperature. The original intensity of the electrical signal output by the pyroelectric infrared sensor, corresponding to the change in voltage difference between the positive and negative sensing surfaces, varies under different ambient temperatures, resulting in different performance characteristics of the infrared detection device. Specifically, human body temperature tends to stabilize at around 37°C, but due to the influence of clothing, the temperature of the infrared radiator in an infrared detection scenario is approximately 32-33°C. When the ambient temperature is also close to 32-33°C, the original intensity change of the electrical signal output by the pyroelectric infrared sensor based on the human body's cross-area movement is extremely weak and difficult to effectively capture. However, when the ambient temperature is low, such as below 0°C, the original intensity of the electrical signal output by the pyroelectric infrared sensor based on the human body's cross-area movement is very high. On the other hand, in radial movement scenarios, high-installation / long-distance detection scenarios, and large-angle detection scenarios, the electrical signal output by the pyroelectric infrared sensor based on the human body's cross-area movement is extremely weak and cannot be accurately amplified, making it difficult to effectively capture based on the corresponding threshold settings.

[0004] Therefore, for both existing infrared detection devices and those employing ultrasonic or Doppler-effect-based microwave detection technologies, ensuring the effective capture of weak signals in the original output signal is crucial to guaranteeing the reliability of the detection device in various scenarios. However, when strong signals coexist in the original output signal, especially when the original output signal is a single-ended signal, the traditional method of amplifying single-ended signals using multi-stage operational amplifiers suffers from poor linearity, leading to a relatively higher amplification factor for strong signals. This can result in strong signal saturation or weak signal distortion, making effective detection impossible. Furthermore, the amplification process is susceptible to fluctuations in the reference ground potential, which introduce and amplify noise interference based on these fluctuations, exacerbating weak signal distortion. Consequently, it is difficult to balance detection sensitivity and accuracy, resulting in a general inability to guarantee the reliability of the detection device in different scenarios. Summary of the Invention

[0005] One objective of this invention is to provide a dual-ended output circuit and a signal processing circuit based on a single-ended signal source. The dual-ended output circuit based on the single-ended signal source, when using the single-ended signal source, has a dual-ended output designed according to a corresponding circuit structure that can be adapted to the two input terminals of an instrumentation amplifier (In-Amp). This leverages the inherent advantages of the instrumentation amplifier—high input impedance, high common-mode rejection ratio, high gain adjustment accuracy, low temperature drift, good linearity, and low noise—to achieve complete and high-precision amplification of the original single-ended signal output from the single-ended signal source. Correspondingly, this facilitates the effective capture of weak signals in the original signal output from the single-ended signal source.

[0006] Another objective of this invention is to provide a dual-ended output circuit and a signal processing circuit based on a single-ended signal source. The dual-ended output circuit based on the single-ended signal source, when using a single-ended signal source, forms a dual-ended output based on the corresponding circuit structure design that is not a differential signal dual-ended output. This breaks the conventional understanding that instrumentation amplifiers are only suitable for inputting differential signals. Furthermore, when connected to the input terminal of an instrumentation amplifier, it can still maintain the aforementioned original advantages of the instrumentation amplifier and achieve complete and high-precision amplification of the original signal output from the single-ended signal source.

[0007] Another objective of this invention is to provide a dual-ended output circuit and a signal processing circuit based on a single-ended signal source. The dual-ended output circuit based on the single-ended signal source, when using a single-ended signal source, is not a differential signal output formed by a corresponding circuit structure design. The corresponding circuit structure design avoids the use of a single-ended to differential circuit design, thus avoiding low-frequency distortion caused by low-frequency coupling loss during the single-ended to differential conversion process. Therefore, it helps to ensure that the dual-ended output signal completely represents the original signal output by the single-ended signal source. In this way, when connected to the input of an instrumentation amplifier, the original signal output by the single-ended signal source can be amplified completely and with high precision.

[0008] Another object of the present invention is to provide a dual-ended output circuit and a signal processing circuit based on a single-ended signal source, wherein the dual-ended output circuit based on the single-ended signal source has a dual-ended output adapted to the two input terminals of an instrumentation amplifier, and the signal processing circuit based on the single-ended signal source amplifies the signal output by the dual-ended output circuit based on the instrumentation amplifier. In this way, based on the aforementioned inherent advantages of the instrumentation amplifier, weak signals in the original signal output by the single-ended signal source can be effectively captured, thereby ensuring the reliability of the corresponding sensing device using the signal processing circuit based on the single-ended signal source when the single-ended signal source is a corresponding sensor.

[0009] Another objective of this invention is to provide a dual-output circuit and signal processing circuit based on a single-ended signal source. In this circuit, the dual-output circuit is adapted to an instrumentation amplifier, which amplifies the original signal output from the single-ended signal source. Leveraging the inherent advantages of the instrumentation amplifier, complete and high-precision amplification of the original signal is achieved, effectively capturing weak signals in the original signal output from the single-ended signal source. When the single-ended signal source is a sensor, the reliability of the corresponding sensing device using the signal processing circuit based on the single-ended signal source is ensured. However, due to the instrumentation amplifier's native support for differential signal input, on the one hand, the single-ended signal output of the single-ended signal source cannot be directly matched with the input of the instrumentation amplifier; on the other hand, weak signals, especially low-frequency weak signals, in the original single-ended signal output from the single-ended signal source will exhibit differential characteristics at the single-ended input. The signal is severely distorted during the conversion process and is not suitable for conversion to differential signals using existing single-ended to differential circuits. Given the conventional understanding that instrumentation amplifiers are only suitable for inputting differential signals, and considering the signal processing requirements for weak signals, especially low-frequency weak signals, in the original single-ended signal output from the single-ended signal source, instrumentation amplifiers are not considered by those skilled in the art to be suitable for amplifying the original single-ended signal output from the single-ended signal source. Therefore, the technical approach of using an instrumentation amplifier to amplify the original single-ended signal output from the single-ended signal source in a dual-ended output circuit based on a single-ended signal source deviates from the conventional signal processing approach of those skilled in the art. However, based on the aforementioned inherent advantages of instrumentation amplifiers, how to achieve a matching design between the dual-ended output circuit based on a single-ended signal source and the instrumentation amplifier has significant technical and commercial value.

[0010] Another object of the present invention is to provide a dual-ended output circuit and a signal processing circuit based on a single-ended signal source, wherein the dual-ended output circuit based on the single-ended signal source is configured with an RC sampling circuit in the state of using the single-ended signal source, wherein the single-ended signal source is configured to output a raw signal in the form of a single-ended signal at its output terminal in the powered state, and the RC sampling circuit includes a pair of ground capacitors and a sampling resistor, one end of the ground capacitors is grounded, and the other end of the ground capacitors is electrically connected to the sampling resistor, and the sampling resistor is opposite to the end connected to the ground capacitors. One end is electrically connected to the output terminal of the single-ended signal source. The dual-ended output circuit based on the single-ended signal source has a dual-ended output adapted to the two input terminals of the instrumentation amplifier, with the two ends of the sampling resistor as the output terminals. Compared with using a single-ended to differential circuit to convert the original signal in single-ended signal form output from the single-ended signal source into a differential signal form output, it simplifies the circuit architecture of the dual-ended output circuit based on the single-ended signal source and significantly shortens the transmission path of the signal output from the output terminal of the single-ended signal source, thereby reducing the noise introduced by the signal transmission path.

[0011] Another objective of this invention is to provide a dual-ended output circuit and a signal processing circuit based on a single-ended signal source. In this circuit, the output terminals of the sampling resistor are matched to the two input terminals of an instrumentation amplifier for differential input. The signal output from the sampling resistor is not a differential signal, but the signal output by the instrumentation amplifier is verified to correspond in frequency to the original single-ended signal from the single-ended signal source and is amplified in intensity relative to the original signal. This achieves amplification of the original signal. In other words, the signal processing circuit based on the single-ended signal source breaks the conventional understanding that instrumentation amplifiers are only suitable for differential signals. The matching design of the dual-ended output circuit based on the sampling resistor is suitable for amplifying the original single-ended signal from the single-ended signal source using an instrumentation amplifier.

[0012] Another objective of this invention is to provide a dual-ended output circuit and a signal processing circuit based on a single-ended signal source. The instrumentation amplifier circuit natively supports differential signal input while having a single-ended signal output, which facilitates digital sampling by an analog-to-digital converter (ADC). Corresponding to the dual-ended output circuit based on the single-ended signal source, in the state of using a single-ended signal source, the matching design based on the two ends of the sampling resistor as the output terminals is suitable for directly using existing IC chips that integrate instrumentation amplifier circuits and analog-to-digital converters to form the signal processing circuit based on the single-ended signal source. This is beneficial for simplifying the circuit architecture of the signal processing circuit based on the single-ended signal source.

[0013] Another objective of this invention is to provide a dual-ended output circuit and signal processing circuit based on a single-ended signal source. When the instrumentation amplifier circuit is integrated into the IC chip as a programmable gain amplifier (PGA) with an instrumentation amplifier architecture, the programmable gain amplifier with an instrumentation amplifier architecture has the advantages of adjustable gain and good linearity. By applying the programmable gain amplifier with an instrumentation amplifier architecture to amplify the original signal of the single-ended signal output from the single-ended signal source, it is possible to simultaneously ensure the effective detection of both strong and weak signals, thereby guaranteeing the adaptability and reliability of the signal processing circuit based on the single-ended signal source in different application scenarios.

[0014] Another object of the present invention is to provide a dual-ended output circuit and a signal processing circuit based on a single-ended signal source, wherein when the IC chip has a multiplexer (MUX) configuration with multiplexed input function, the state of the signal processing circuit based on the single-ended signal source can be matched with multiple dual-ended output circuits based on the single-ended signal source. Furthermore, the types of single-ended signal sources in each dual-ended output circuit are not limited to the same type. For example, at least one single-ended signal source can be configured as a pyroelectric infrared sensing circuit and at least one single-ended signal source can be configured as a microwave sensing module based on the Doppler effect principle to achieve dual-technology detection. This avoids the problem of excessive power consumption by avoiding the use of multiplexed amplification. The configuration of multiple dual-ended output circuits based on the single-ended signal source in the signal processing circuit based on the single-ended signal source simplifies the circuit architecture of the signal processing circuit based on the single-ended signal source.

[0015] To achieve at least one of the above objectives, according to one aspect of the present invention, a dual-ended output circuit based on a single-ended signal source is provided, the dual-ended output circuit based on a single-ended signal source comprising:

[0016] A single-ended signal source, the single-ended signal source being configured to output a raw signal in a single-ended signal form at its output terminal when powered; and

[0017] An RC sampling circuit includes a pair of ground capacitors and a sampling resistor. One end of the ground capacitor is grounded, and the other end of the ground capacitor is electrically connected to the sampling resistor. The end of the sampling resistor opposite to the end connected to the ground capacitor is electrically connected to the output terminal of the single-ended signal source. The dual-ended output circuit based on the single-ended signal source, with the two ends of the sampling resistor as the output terminals, forms a dual-ended output that can be adapted to the two input terminals of the instrumentation amplifier. The time constant of the RC sampling circuit is less than or equal to 1.5s.

[0018] In one embodiment, the dual-ended output circuit based on a single-ended signal source further includes a first resistor and a first capacitor, wherein the single-ended signal source is electrically connected to the sampling resistor via the first resistor, one end of the first resistor electrically connected to the sampling resistor is further connected to one end of the first capacitor, and the other end of the first capacitor is grounded.

[0019] In one embodiment, the dual-ended output circuit based on a single-ended signal source further includes a second capacitor, wherein the second capacitor is connected in parallel with the sampling resistor.

[0020] In one embodiment, the sampling resistor is electrically connected to the ground capacitor via a second resistor.

[0021] In one embodiment, the single-ended signal source is configured as a pyroelectric infrared sensing circuit.

[0022] In one embodiment, the infrared sensing circuit is configured in the form of a pyroelectric infrared sensing probe and has a power supply terminal for connecting to a power source, a signal output terminal for outputting the original signal in analog form, and a ground terminal for grounding.

[0023] In one embodiment, the power supply terminal is connected to the power supply via at least one stage of filter circuit. The filter circuit is designed as a series RC circuit with the end of the resistor R in the series RC circuit opposite to the end of the capacitor C connected in series as the input terminal connected to the power supply, the end of the resistor R connected in series with the capacitor C as the output terminal, and the end of the capacitor C opposite to the end of the resistor R connected in series as grounded.

[0024] In one embodiment, the single-ended signal source is configured as a microwave sensing module based on the Doppler effect principle.

[0025] In one embodiment, the single-ended signal source is configured as an ultrasonic detection sensor.

[0026] According to another aspect of the present invention, the present invention also provides a signal processing circuit based on a single-ended signal source, the signal processing circuit based on a single-ended signal source comprising:

[0027] A single-ended signal source, the single-ended signal source being configured to output a raw signal in a single-ended signal form at its output terminal when powered;

[0028] An RC sampling circuit includes a pair of ground capacitors and a sampling resistor. One end of the ground capacitors is grounded, and the other end of the ground capacitors is electrically connected to the sampling resistor. The end of the sampling resistor opposite to the end connected to the ground capacitors is electrically connected to the output terminal of the single-ended signal source.

[0029] An instrumentation amplifier, wherein the two ends of the sampling resistor are the output terminals, and the instrumentation amplifier is used to amplify the signals output from the two output terminals.

[0030] In one embodiment, the single-ended signal source is configured as a pyroelectric infrared sensing circuit.

[0031] In one embodiment, the single-ended signal source is configured as a microwave sensing module based on the Doppler effect principle.

[0032] In one embodiment, the single-ended signal source is configured as an ultrasonic detection sensor.

[0033] In one embodiment, the signal processing circuit based on the single-ended signal source further uses an analog-to-digital conversion unit to digitally sample the signal output by the instrumentation amplifier.

[0034] In one embodiment, the instrumentation amplifier circuit and the analog-to-digital converter are integrated into an IC chip.

[0035] In one embodiment, the instrumentation amplifier circuit is integrated into the IC chip as a programmable gain amplifier employing an instrumentation amplifier architecture.

[0036] In one embodiment, the IC chip further integrates a microcontroller unit, which is used to receive the signal output by the analog-to-digital converter unit to analyze and judge the signal.

[0037] In one embodiment, the IC chip further integrates a multiplexer to provide multiple input selection functionality. The number of dual-ended output circuits based on the single-ended signal source, consisting of the single-ended signal source and the RC sampling circuit, is multiple. The two ends of the sampling resistor of each dual-ended output circuit based on the single-ended signal source are selectively connected to the two input terminals of a programmable gain amplifier with an instrumentation amplifier architecture for differential input via the corresponding input terminals of the multiplexer.

[0038] In one embodiment, among the plurality of dual-ended output circuits based on single-ended signal sources, at least one of the single-ended signal sources is configured as a pyroelectric infrared sensing circuit and at least one of the single-ended signal sources is configured as a microwave sensing module based on the Doppler effect principle.

[0039] The further objects and advantages of the invention will become fully apparent from the following description and accompanying drawings. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the circuit structure of a signal processing circuit based on a single-ended signal source according to an embodiment of the present invention.

[0041] Figure 2A This is an experimental circuit diagram of a signal processing circuit based on a single-ended signal source, corresponding to the above embodiments of the present invention.

[0042] Figure 2B This is a signal diagram obtained by sampling with an oscilloscope under the above experimental circuit framework diagram.

[0043] Figure 2C This is a signal diagram obtained by printing data after signal digitization and reconstruction under the above experimental circuit framework diagram.

[0044] Figure 3A The experimental circuit framework diagram built to verify the characteristics of differential signals with equal amplitude and phase inversion.

[0045] Figure 3B This is a signal diagram obtained by sampling with an oscilloscope under the above experimental circuit framework diagram.

[0046] Figure 4 The above-described embodiment of the present invention, based on a single-ended signal source, is used in a practical detection application to print a signal diagram obtained after the signal is digitized and restored.

[0047] Figure 5A This is an optimization scheme for a dual-ended output circuit based on a single-ended signal source, based on the structure of the signal processing circuit based on a single-ended signal source in the above embodiments of the present invention.

[0048] Figure 5B This is another optimization scheme for a dual-ended output circuit based on a single-ended signal source, based on the structure of the signal processing circuit based on a single-ended signal source in the above embodiments of the present invention.

[0049] Figure 5C This is another optimization scheme for a dual-ended output circuit based on a single-ended signal source, based on the structure of the signal processing circuit based on a single-ended signal source in the above embodiments of the present invention.

[0050] Figure 6 This is another optimization scheme for a dual-ended output circuit based on a single-ended signal source, based on the structure of the signal processing circuit based on a single-ended signal source in the above embodiments of the present invention.

[0051] Figure 7 This is an optimization scheme formed by combining two optimization schemes from the aforementioned optimization scheme, based on the structure of the signal processing circuit based on a single-ended signal source in the above embodiments of the present invention.

[0052] Figure 8 This is a schematic diagram of a circuit structure for applying a signal processing circuit based on a single-ended signal source in infrared detection according to the above embodiments of the present invention.

[0053] Figure 9 This invention provides an optimized solution for applying the signal processing circuit based on a single-ended signal source in the above embodiments of the present invention to infrared detection.

[0054] Figure 10 This is a schematic diagram of a circuit structure for applying a single-ended signal source-based signal processing circuit of the above embodiments of the present invention to multi-channel detection.

[0055] Figure 11 This is an integrated scheme for a signal processing circuit based on a single-ended signal source, as described in the above embodiments of the present invention. Detailed Implementation

[0056] The following description is intended to disclose the present invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0057] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0058] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0059] This invention provides a dual-ended output circuit and a signal processing circuit based on a single-ended signal source. The signal processing circuit based on the single-ended signal source is configured to amplify the original single-ended signal output from the single-ended signal source using an instrumentation amplifier (In-Amp). This leverages the inherent advantages of the instrumentation amplifier—high input impedance, high common-mode rejection ratio, high gain adjustment accuracy, low temperature drift, good linearity, and low noise—to achieve complete and high-precision amplification of the original single-ended signal output from the single-ended signal source. This facilitates the effective capture of weak signals in the original signal output from the single-ended signal source, ensuring the reliability of the corresponding sensing device using the signal processing circuit based on the single-ended signal source when the single-ended signal source is a sensor.

[0060] However, due to the limitation that the instrumentation amplifier natively supports differential signal input, on the one hand, the output of the single-ended signal source in single-ended signal form cannot be directly matched with the input of the instrumentation amplifier. On the other hand, weak signals in the original single-ended signal form output by the single-ended signal source, especially low-frequency weak signals, will be severely distorted during the single-ended to differential conversion process and are not suitable for conversion into differential signals by existing single-ended to differential circuits. Corresponding to the conventional understanding that the instrumentation amplifier is only suitable for inputting differential signals, based on the signal processing requirements of retaining the weak signals in the original single-ended signal form output by the single-ended signal source, especially low-frequency weak signals, the instrumentation amplifier is not considered by those skilled in the art to be able to amplify the original single-ended signal form output by the single-ended signal source. Therefore, the technical approach of using an instrumentation amplifier to amplify the signal output by the dual-ended output circuit based on a single-ended signal source, which is in the state of using a single-ended signal source, deviates from the conventional signal processing approach of those skilled in the art. However, based on the aforementioned inherent advantages of the instrumentation amplifier, how to achieve the matching design between the dual-ended output circuit based on a single-ended signal source and the instrumentation amplifier has significant technical and commercial value.

[0061] Specifically, refer to the accompanying drawings of the specification of this invention. Figure 1As shown, to achieve the matching design between the dual-ended output circuit 10 based on the single-ended signal source and the instrumentation amplifier 20, so that the signal output by the dual-ended output circuit 10 based on the single-ended signal source can be amplified by the instrumentation amplifier 20, a circuit structure of a signal processing circuit based on a single-ended signal source according to an embodiment of the present invention is illustrated. The dual-ended output circuit 10 based on the single-ended signal source is configured with an RC sampling circuit 12 when using a single-ended signal source 11. The single-ended signal source 11 is configured to output a raw signal in single-ended signal form at its output terminal when powered. The RC sampling circuit 12 includes a pair of ground capacitors 121 and a sampling resistor 122. One end of the ground capacitor 121 is grounded. The other end of 21 is electrically connected to the sampling resistor 122. The end of the sampling resistor 122 opposite to one end connected to the ground capacitor 121 is electrically connected to the output terminal of the single-ended signal source 11. The dual-ended output circuit 10 based on the single-ended signal source has a dual-ended output adapted to the two input terminals of the instrumentation amplifier 20, with the two ends of the sampling resistor 122 as the output terminals. Compared with using a single-ended to differential circuit to convert the original signal in single-ended signal form output from the single-ended signal source 11 into a differential signal form output, it simplifies the circuit architecture of the dual-ended output circuit 10 based on the single-ended signal source and greatly shortens the transmission path of the signal output from the output terminal of the single-ended signal source 11, which is beneficial to reducing the noise introduced by the signal transmission path.

[0062] In other words, the dual-ended output circuit 10 based on a single-ended signal source of the present invention is configured with the RC sampling circuit 12 in the state of using a single-ended signal source 11, and the dual-ended output formed by taking the two ends of the sampling resistor 122 as the output terminals can be adapted to the two input terminals of the instrumentation amplifier 20. Correspondingly, in the state where the instrumentation amplifier 20 amplifies the signal output by the dual-ended output circuit 10 based on the single-ended signal source and inputs the signal to the two input terminals of the instrumentation amplifier 20 for differential input, the signal processing circuit based on the single-ended signal source is formed. In this way, when the single-ended signal source 11 is the corresponding sensor, the reliability of the corresponding sensing device using the signal processing circuit based on the single-ended signal source is guaranteed.

[0063] It is worth mentioning that the dual-ended output circuit 10 based on a single-ended signal source, with the two ends of the sampling resistor 122 as output terminals, is connected to the two input terminals of the instrumentation amplifier 20 for differential input. The signal output from the two ends of the sampling resistor 122 is not a differential signal, but the electrical signal output by the instrumentation amplifier 20 still corresponds in frequency to the signal output by the single-ended signal source 11 and is amplified in intensity relative to the signal output by the single-ended signal source 11. This results in amplification of the original single-ended signal output from the single-ended signal source 11. In other words, the signal processing circuit based on the single-ended signal source breaks the conventional understanding that the instrumentation amplifier 20 is only suitable for differential signals. Based on the matching design of the dual-ended output circuit 10 with the two ends of the sampling resistor 122 as output terminals, the instrumentation amplifier 20 can amplify the original single-ended signal output from the single-ended signal source 11.

[0064] It is understandable that, for the RC sampling circuit 12, if the end of the sampling resistor 122 opposite to the end connected to the capacitor 121 to ground is taken as the input terminal, and the end of the sampling resistor 122 connected to the capacitor 121 to ground is taken as the output terminal, the RC sampling circuit 12 can be understood as a low-pass filter circuit. However, in this embodiment of the present invention, when the dual-ended output circuit 10 based on the single-ended signal source takes both ends of the sampling resistor 122 as the output terminal, due to the high input impedance of the two input terminals of the instrumentation amplifier 20 used for differential input, the influence of the internal circuit structure design of the instrumentation amplifier 20, and the change in the port nature of the end of the sampling resistor 122 opposite to the end connected to the capacitor 121 to ground (from only serving as an input terminal to simultaneously serving as an input terminal and an output terminal), the RC sampling circuit 12 in this embodiment of the present invention is not suitable to be understood as a low-pass filter circuit. Even if the RC sampling circuit 12 is understood as a low-pass filter circuit, the signal output with the two ends of the sampling resistor 122 as the output terminals is not a differential signal.

[0065] Specifically, to verify that the signal output by the dual-ended output circuit 10 based on a single-ended signal source, with the two ends of the sampling resistor 122 as the output terminals, is not a differential signal, and to verify that the dual-ended output formed by the dual-ended output circuit 10 based on a single-ended signal source, with the two ends of the sampling resistor 122 as the output terminals, can be matched to the two input terminals of the instrumentation amplifier 20 for differential input, in Figure 2A Under the experimental circuit framework shown, the corresponding verification results are... Figure 2B and Figure 2C It was displayed in the middle.

[0066] Corresponding to Figure 2AThe experimental circuit framework shown is as follows: In the RC sampling circuit 12, the end of the sampling resistor 122 opposite to one end of the capacitor 121 connected to ground is the front end of the resistor, and the end of the sampling resistor 122 connected to the capacitor 121 connected to ground is the back end of the resistor. The original signal of the single-ended signal source 11 is simulated by injecting a sine wave signal with a frequency of 0.75Hz, an amplitude of 1.00V, and a DC bias of 0.75V into the front end of the RC sampling circuit 12 using a signal generator. When the front end of the RC sampling circuit 12 is sampled by an oscilloscope with a single-ended probe having a ground wire, the signal obtained is... Figure 2B The CH1 signal in the RC sampling circuit 12 is obtained when sampled by an oscilloscope with a single-ended probe having a ground wire at the resistor downstream of the RC sampling circuit 12. Figure 2B The CH2 signal in the RC sampling circuit 12 is obtained when sampled across the sampling resistor 122 using an oscilloscope with a dual-probe differential probe. Figure 2B When the CH3 signal in the RC sampling circuit 12 is connected to the two ends of the sampling resistor 122, the IC chip of the integrated instrumentation amplifier 20 (the IC chip model CS1237 provided by Chipsea Technologies) is used to digitally restore the signal output by the IC chip and then print the data. Figure 2C The signal in. Among them, Figure 2B The CH1 and CH2 signals deviate completely from the characteristics of equal-amplitude, out-of-phase differential signals. Therefore, the signal output by the dual-ended output circuit 10 based on the single-ended signal source, with the two ends of the sampling resistor 122 as the output terminals, is verified to be not a differential signal. Figure 2C The signal in the signal generator is still able to correspond in frequency to the frequency of the signal injected by the signal generator and be amplified in intensity relative to the injected signal. The dual-ended output formed by the dual-ended output circuit 10 based on the single-ended signal source with the two ends of the sampling resistor 122 as the output terminals is verified to be able to match the two input terminals of the instrumentation amplifier 20 for differential input.

[0067] It is understandable that a single-ended signal is a voltage signal transmitted through a single conductor, consisting of a reference terminal (usually ground) and a signal terminal. The signal value is the potential difference between the conductor and ground. This corresponds to the voltage difference obtained when the two ends of the sampling resistor 122 are sampled using an oscilloscope with a single-ended probe having a ground wire. Figure 2B The CH1 and CH2 signals are single-ended signals between the two ends of the sampling resistor 122 and ground, respectively. The differential signal, on the other hand, is an equal-amplitude, inverse signal transmitted over two wires, for example, in... Figure 3AIn the circuit framework shown, the signals output from the inverter are differential signals. This corresponds to the signals obtained when the inverter is sampled at both ends using an oscilloscope with a single-ended probe connected to ground. Figure 3B Although the CH1 and CH2 signals are single-ended signals between the two ends of the inverter and ground, based on the characteristic of differential signals being inverted with equal amplitude, these two single-ended signals can still exhibit the characteristic of being inverted with equal amplitude relative to a common reference potential. Therefore, the signal output from the two ends of the sampling resistor 122 can be understood as a two-ended signal with relative voltage difference changes that are mutually referenced; this signal is neither a single-ended signal nor a differential signal.

[0068] It is worth mentioning that the signal output by the dual-ended output circuit 10 based on the single-ended signal source with the two ends of the sampling resistor 122 as the output terminals is not a differential signal. However, the dual-ended output formed by the dual-ended output circuit 10 based on the single-ended signal source with the two ends of the sampling resistor 122 as the output terminals can be matched with the two input terminals of the instrumentation amplifier 20 for differential input. This makes the dual-ended output circuit 10 based on the single-ended signal source 11 suitable for the instrumentation amplifier 20 to amplify the original signal in the single-ended signal form output by the single-ended signal source 11. Therefore, since the dual-ended output formed by the dual-ended output circuit 10 based on a single-ended signal source, with the two ends of the sampling resistor 122 as the output terminals, has been verified to match the state of the two input terminals of the instrumentation amplifier 20 for differential input, the technical and commercial value of the dual-ended output circuit 10 based on the single-ended signal source and the signal processing circuit based on the single-ended signal source has been demonstrated. Although the specific logic of the dual-ended output formed by the dual-ended output circuit 10 based on the single-ended signal source, with the two ends of the sampling resistor 122 as the output terminals, matching the state of the two input terminals of the instrumentation amplifier 20 for differential input lacks direct principle revelation, for a better understanding of the present invention, the dual-ended output formed by the dual-ended output circuit 10 based on the single-ended signal source, with the two ends of the sampling resistor 122 as the output terminals, has been verified to match the state of the two input terminals of the instrumentation amplifier 20 for differential input, based on the understanding of the circuit principle of the differential probe of the oscilloscope and the... Figure 2B Based on the morphological analysis of the CH3 signal, the applicant of this invention makes the following inference regarding the underlying logic of the dual-ended output circuit 10 based on the single-ended signal source, which forms a dual-ended output with the two ends of the sampling resistor 122 as the output terminals, and which can match the two input terminals of the instrumentation amplifier 20 for differential input:

[0069] In the dual-ended output circuit 10 based on a single-ended signal source, corresponding to Figure 1Based on the circuit structure, the original signal in single-ended signal form output by the single-ended signal source 11 forms an AC loop with ground as the reference potential through the RC sampling circuit 12. When the two ends of the sampling resistor 122 are the output terminals, due to the DC blocking and AC passing characteristics of the ground capacitor 121, the DC bias of the two ends of the sampling resistor 122 to ground tends to be synchronized. Correspondingly, when a single-ended probe with a grounded wire is used to sample the two ends of the sampling resistor 122 with an oscilloscope, the acquired signal corresponds to... Figure 2B The CH1 and CH2 signals are two single-ended signals with similar DC bias. Analyzing these signals as single-ended signals offers no advantage over directly analyzing the original single-ended signal form. Furthermore, the AC components in these two signals do not exhibit equal amplitude and inverse phase characteristics relative to any reference potential, thus preventing them from forming a differential signal with dual-ended output. Therefore, the circuit structure design of the dual-ended output circuit 10 based on the single-ended signal source, with the two ends of the sampling resistor 122 as the output terminals, does not conform to the conventional signal processing approach of those skilled in the art. However, if the signals output from both ends of the sampling resistor 122 are considered as mutually referenced signals with relative voltage difference changes, this signal is neither a single-ended signal nor a differential signal. However, due to the mutual reference and isolation from ground based on the DC blocking and AC passing characteristics of the ground capacitor 121, the amplitude (relative voltage difference) change only reflects the AC component in the original single-ended signal output from the single-ended signal source 11. This effectively shields against the jitter of the reference ground potential and suppresses the drift of the DC bias voltage. Corresponding to the state of the differential probe of the instrumentation amplifier 20 or oscilloscope with differential characteristics, the sampling resistor 122 and the differential probe of the instrumentation amplifier 20 or oscilloscope can form a closed loop isolated from ground, allowing the final output signal to correspond to... Figure 2B The CH3 signal in the signal corresponds to the original signal of the single-ended signal output by the single-ended signal source 11 in terms of frequency, and the AC component in the original signal of the single-ended signal output by the single-ended signal source 11 is completely restored in terms of frequency characteristics by eliminating the DC bias voltage.

[0070] In other words, in the dual-ended output circuit 10 based on a single-ended signal source and the signal processing circuit based on a single-ended signal source described in this invention, the signals output from both ends of the sampling resistor 122 should be understood as mutually referenced signals with relative voltage difference changes in a dual-ended form. This signal is neither a single-ended signal nor a differential signal. However, due to mutual reference and isolation from ground based on the DC blocking and AC passing characteristics of the ground capacitor 121, the amplitude (relative voltage difference) change only reflects the AC component in the original signal of the single-ended signal output from the single-ended signal source 11. That is, it can shield the jitter effect of the reference ground potential and suppress the drift effect of the DC bias voltage. Corresponding to the state when the signal is input into the differential probe of the instrumentation amplifier 20 or the oscilloscope with differential characteristics, the output signal corresponds to Figure 2B The CH3 signal in the signal corresponds to the original signal of the single-ended signal output by the single-ended signal source 11 in terms of frequency and eliminates the DC bias voltage, thus completely restoring the AC component in the original signal of the single-ended signal output by the single-ended signal source 11 in terms of frequency characteristics.

[0071] Simply put, due to the DC blocking and AC passing characteristics of the ground capacitor 121, the original signal in the single-ended signal form output by the single-ended signal source 11, with ground as the reference potential, can form an AC loop through the RC sampling circuit 12 but cannot form a DC loop. Correspondingly, when the two ends of the sampling resistor 122 are the output terminals, the DC voltages of the two ends of the sampling resistor 122 relative to ground tend to be synchronized. However, for the formed AC loop, there is a voltage difference between the AC voltages of the two ends of the sampling resistor 122 relative to ground, and the frequency of the voltage difference change corresponds to the frequency of the AC component in the original signal in the single-ended signal form output by the single-ended signal source 11. Thus, when the signal output from the two ends of the sampling resistor 122 is understood as a double-ended signal with a relative voltage difference change that is mutually referenced, the relative voltage difference change of the double-ended signal only feeds back the AC component in the original signal in the single-ended signal form output by the single-ended signal source 11.

[0072] Specifically, if the RC sampling circuit 12 is understood as a low-pass filter circuit, when the time constant of the RC sampling circuit 12 is large enough that the cutoff frequency of the low-pass filter circuit is low enough to approach DC, on the one hand, most of the AC energy in the original signal of the single-ended signal output by the single-ended signal source 11 will be lost to ground through the ground capacitor 121. Correspondingly, the signal energy output from the end of the sampling resistor 122 that is electrically connected to the output terminal of the single-ended signal source 11 will be weakened. On the other hand, the reference ground potential jitter and DC bias voltage caused by environmental factors and the circuit system's own operating temperature changes in the original signal will be weakened. Regarding drift and extremely low-frequency noise that tends to change to DC, this type of noise approaches the cutoff frequency of the low-pass filter circuit in frequency and is affected by the amplitude-frequency characteristics of the low-pass filter circuit. In terms of amplitude, it has a large amplitude difference across the two ends of the sampling resistor 122. Therefore, when the two ends of the sampling resistor 122 are connected to the two input terminals of the instrumentation amplifier 20 with high input impedance, it is impossible to guarantee the signal strength output from the end of the sampling resistor 122 that is electrically connected to the output terminal of the single-ended signal source 11, nor can it effectively suppress this type of noise interference in the signal amplified and output by the instrumentation amplifier 20 based on the difference characteristic of the instrumentation amplifier 20.

[0073] Therefore, in the dual-ended output circuit 10 based on a single-ended signal source of the present invention, the time constant of the RC sampling circuit 12 is preferably set to be less than or equal to 1.5s, so that when the RC sampling circuit 12 is understood as a low-pass filter circuit, the low-pass filter circuit allows at least a portion of the effective signal in the AC component of the original signal to pass through, that is, the ground-to-ground configuration of the signal output from one end of the sampling resistor 122 electrically connected to the ground capacitor 121 is similar to that of the sampling resistor 122. Figure 2B The CH2 signal contains at least a portion of the effective signal from the AC component of the original signal. When the two ends of the sampling resistor 122 are connected to the two input terminals of the instrumentation amplifier 20 with high input impedance, the signal strength output from the two ends of the sampling resistor 122 is guaranteed. Because the aforementioned extremely low frequency noise is extremely low in frequency and far from the cutoff frequency of the low-pass filter circuit, this type of extremely low frequency noise has a similar phase and amplitude at the two ends of the sampling resistor 122. Therefore, it is beneficial to suppress this type of noise interference in the signal amplified and output by the instrumentation amplifier 20 based on the difference characteristic of the instrumentation amplifier 20. The time constant of the RC sampling circuit 12 is in seconds and corresponds to the product between the resistance value of the sampling resistor 122 in megaohms (MΩ) and the capacitance value of the capacitance to ground 121 in microfarads (μF).

[0074] It is worth mentioning that the signal output from both ends of the sampling resistor 122 can be understood as a two-terminal signal with relative voltage difference changes that are mutually referenced. Although this signal is not a differential signal, inputting this signal into the instrumentation amplifier 20 does not affect the aforementioned inherent advantages of the instrumentation amplifier 20, including the common-mode interference immunity advantage due to the circuit design that supports differential signal input. Compared to converting the original single-terminal signal output from the single-terminal signal source 11 into a differential signal output before inputting it into the instrumentation amplifier 20, it can suppress the noise generated in the original single-terminal signal output from the single-terminal signal source 11 due to the jitter of the reference ground potential and the drift of the DC bias voltage.

[0075] For example, when the original single-ended signal output from the single-ended signal source 11 is affected by jitter in the reference ground potential or drift in the DC bias voltage, resulting in corresponding noise interference, if the original single-ended signal output from the single-ended signal source 11 is converted into a differential signal output, the noise interference will be indiscriminately converted into a differential signal and exist as differential-mode interference in the converted differential signal. Therefore, converting the original single-ended signal output from the single-ended signal source 11 into a differential signal output before inputting it into the instrumentation amplifier 20 cannot eliminate the noise interference present in the original signal due to jitter in the reference ground potential and drift in the DC bias voltage. However, in the dual-ended output circuit 10 based on a single-ended signal source and the signal processing circuit based on a single-ended signal source described in this invention, the signals output from both ends of the sampling resistor 122 are understood as signals with relative voltage difference changes that are mutually referenced. Based on the DC blocking and AC passing characteristics of the ground capacitor 121, the noise interference generated in the original signal of the single-ended signal form output by the single-ended signal source 11 due to the influence of ground potential jitter or DC bias voltage drift will be synchronized to both ends of the sampling resistor 122 and exist in the form of common-mode interference in the dual-ended signal. Therefore, when the signal is input to the instrumentation amplifier 20, the common-mode interference resistance advantage of the instrumentation amplifier 20 can be suppressed. Correspondingly, the closed loop formed between the sampling resistor 122 and the instrumentation amplifier 20 or the differential probe of the oscilloscope can be isolated from the ground to shield the influence of reference ground potential jitter and suppress the influence of DC bias voltage drift.

[0076] When the single-ended signal source 11 is a corresponding sensor, the reference ground potential jitter and DC bias voltage drift caused by environmental factors and the circuit system itself due to changes in operating temperature, as well as the extremely low frequency noise that tends to change with DC, can all be suppressed, thereby improving the signal-to-noise ratio of the signal amplified and output by the instrumentation amplifier circuit 20, thus ensuring the reliability of the corresponding sensing device using the signal processing circuit based on the single-ended signal source.

[0077] For example, when the single-ended signal source 11 is an analog pyroelectric infrared sensor, the thermal noise interference caused by the alternating hot and cold airflow due to environmental factors such as opening and closing doors and weather changes, the self-excitation interference caused by repeated shaking due to wind and rain in outdoor scenarios, and the interference caused by the change of circuit system parameters due to changes in operating temperature with working time and environment can all be effectively suppressed, thus ensuring the signal-to-noise ratio of the signal amplified and output by the instrumentation amplifier circuit 20, thereby realizing complete and high-precision amplification processing of the original signal output by the single-ended signal source 11.

[0078] For example, in Figure 1 Based on the structure of the signal processing circuit based on the single-ended signal source shown, when the single-ended signal source 11 is an analog pyroelectric infrared sensor, in practical detection applications, corresponding to Figure 2A The experimental circuit framework shown also uses a microcontroller unit (MCU) to digitize and restore the signals output by the IC chip, and then prints the data to obtain the output data. Figure 4 As shown in the signal, when a strong signal exists in the original signal output by the single-ended signal source 11, the variation characteristics of the weak signal are still preserved with high precision, thus achieving complete and high-precision amplification of the original signal output by the single-ended signal source 11.

[0079] It is worth mentioning that, based on the understanding and practical verification in the foregoing inference, the suppression principle of extremely low-frequency noise with DC-like variations in the signal processing circuit based on the single-ended signal source of the present invention is completely different from the suppression principle of a filter for a specific frequency signal. Specifically, in the signal processing circuit based on the single-ended signal source of the present invention, due to the DC blocking and AC passing characteristics of the ground capacitor 121, the extremely low-frequency noise with DC-like variations, like the noise interference caused by the drift of the DC bias voltage, will be synchronized to both ends of the sampling resistor 122 in real time. In the double-ended signal output with the two ends of the sampling resistor 122 as the output terminals, it exists in the form of common-mode interference, and thus can be suppressed in real time based on the anti-common-mode interference advantage of the instrumentation amplifier 20. However, when using a filter to suppress signals of a specific frequency, especially extremely low frequencies with DC-like variations, severe time delays will occur, destroying the real-time performance and integrity of the signal and easily causing signal distortion.

[0080] It is understood that, in the description of this invention, the description of "electrical connection" is not limited to a connection relationship that can form a DC path. For example, in the description that "the end of the sampling resistor 122 opposite to the end connected to the ground capacitor 121 is electrically connected to the output terminal of the single-ended signal source 11", it also includes the connection relationship that the end of the sampling resistor 112 opposite to the end connected to the ground capacitor 111 is electrically connected to the output terminal of the single-ended signal source 11 through a corresponding AC path (such as a capacitor). This invention does not limit this.

[0081] Furthermore, in the description of this invention, the sampling resistor 122 may be an equivalent resistance formed by multiple resistors in series and / or parallel; similarly, the capacitance to ground 121 may also be an equivalent capacitance formed by multiple capacitors in series and / or parallel, and this invention is not limited in this respect.

[0082] For example, in Figure 1 Based on the illustrated signal processing circuit structure of the single-ended signal source, in the state where the sampling resistor 122 is electrically connected to the ground capacitor 121 via an additional capacitor, this additional capacitor, connected in series with the ground capacitor 121, can be equivalently understood as a single ground capacitor 121. However, in the state where the sampling resistor 122 is electrically connected to the ground capacitor 121 via an additional resistor, since the dual-ended output circuit 10 based on the single-ended signal source still uses both ends of the sampling resistor 122 as output terminals, this additional resistor should not be equivalently understood as a single sampling resistor 122. However, the corresponding circuit structure still conforms to the circuit structure relationship that "one end of the ground capacitor 121 is grounded, and the other end of the ground capacitor 121 is electrically connected to the sampling resistor 122".

[0083] Furthermore, in Figure 1 Based on the circuit structure of the dual-ended output circuit 10 based on a single-ended signal source shown in the figure, the present invention also provides an exemplary solution for improving the anti-high-frequency interference capability of the dual-ended output circuit 10 based on a single-ended signal source.

[0084] Specifically, in one embodiment, the dual-ended output circuit 10 based on a single-ended signal source corresponds to Figure 5AThe circuit further includes a first resistor 13 and a first capacitor 14, wherein the single-ended signal source 11 is electrically connected to the sampling resistor 122 via the first resistor 13. One end of the first resistor 13, which is electrically connected to the sampling resistor 122, is further connected to one end of the first capacitor 14. The other end of the first capacitor 14 is grounded. In this way, a low-pass filter network is formed based on the matching design of the first resistor 13 and the first capacitor 14 to improve the anti-high frequency interference capability of the dual-ended output circuit 10 based on the single-ended signal source.

[0085] In another embodiment, the dual-ended output circuit 10 based on a single-ended signal source corresponds to Figure 5B It further includes a second capacitor 15, wherein the second capacitor 15 is connected in parallel with the sampling resistor 122, and is designed based on the corresponding parameters of the second capacitor 15, so that the high-frequency signal in the dual-ended output circuit 10 based on the single-ended signal source, which outputs the dual-ended signal with the two ends of the sampling resistor 122 as the output terminals, can be canceled, thereby improving the anti-high-frequency interference capability of the dual-ended output circuit 10 based on the single-ended signal source.

[0086] In particular, Figure 5A The scheme of designing a low-pass filter network based on the matching of the first resistor 13 and the first capacitor 14 can be combined with... Figure 5B The sampling resistor 122 and the second capacitor 15 are combined to form a scheme corresponding to Figure 5C The circuit design scheme.

[0087] In particular, Figure 1 Based on the circuit structure of the dual-ended output circuit 10 based on a single-ended signal source shown in the diagram, it can also correspond to... Figure 6 The high-frequency interference immunity of the dual-ended output circuit 10 based on a single-ended signal source is optimized by setting an additional resistor between the sampling resistor 122 and the ground capacitor 121. The sampling resistor 122 is electrically connected to the ground capacitor 121 via a second resistor 16. Corresponding to the foregoing description, in the state where the sampling resistor 122 is electrically connected to the ground capacitor 121 via the second resistor 16, since the dual-ended output circuit 10 based on a single-ended signal source still uses both ends of the sampling resistor 122 as output terminals, the second resistor 16 should not be understood as equivalent to the sampling resistor 122. However, the corresponding circuit structure still conforms to the circuit structure relationship that "one end of the ground capacitor 121 is grounded, and the other end of the ground capacitor 121 is electrically connected to the sampling resistor 122".

[0088] It is worth mentioning that, in the above embodiments of the present invention, corresponding to Figures 5A to 5CThe scheme for improving the anti-high frequency interference capability of the dual-ended output circuit 10 based on a single-ended signal source, and corresponding to Figure 6 The schemes for optimizing the anti-high frequency interference capability of the dual-ended output circuit 10 based on a single-ended signal source can be combined with each other, for example, by combining the corresponding... Figure 5C The scheme and corresponding Figure 6 The combination of schemes can obtain the corresponding Figure 7 The present invention will not elaborate on the proposed solution.

[0089] Specifically, in these embodiments of the invention, the single-ended signal source 11 can be configured as a pyroelectric infrared sensing circuit, and the infrared sensing circuit corresponds to the state in which the pyroelectric infrared sensing probe is set. Figure 8 Corresponding to the state where the single-ended signal source 11 is set as the pyroelectric infrared sensing circuit 11, the dual-ended output circuit 10 based on the single-ended signal source can also be integrated into a probe shape, either as a whole or in part. For example, the pyroelectric infrared sensing circuit and the sampling resistor 122 in the RC sampling circuit 12 can be integrated into a probe shape. This invention does not limit this.

[0090] It is worth mentioning that, in the infrared sensing circuit corresponding to Figure 8 With the pyroelectric infrared sensor probe set up, the pyroelectric infrared sensor probe has a power supply terminal (D terminal) for connecting to a power source, a signal output terminal (S terminal) for outputting the original signal in analog form, and a ground terminal (G terminal) for grounding, wherein the power supply terminal of the pyroelectric infrared sensor probe optionally corresponds to Figure 9 The power supply is connected through at least one stage of filter circuit 111, wherein the filter circuit 111 is designed as a series RC circuit with the end of the resistor R in the series RC circuit opposite to the end connected in series with the capacitor C as the input terminal, the end of the resistor R connected in series with the capacitor C as the output terminal, and the end of the capacitor C opposite to the end connected in series with the resistor R as the ground, so as to improve the stability of the signal output by the pyroelectric infrared sensor probe based on the arrangement of at least two stages of the filter circuit 111.

[0091] In particular, in the corresponding Figure 8 In the signal processing circuit based on the single-ended signal source, the instrumentation amplifier 20 has a single-ended signal output and is further digitized by the analog-to-digital converter (ADC) 30. Corresponding to the dual-ended output circuit 10 based on the single-ended signal source, when using the single-ended signal source 11, the matching design based on the two ends of the sampling resistor 122 as the output terminals is suitable for directly using existing IC chips that integrate the instrumentation amplifier circuit 20 and the analog-to-digital converter 30 to form the signal processing circuit based on the single-ended signal source, which is beneficial to simplifying the circuit architecture of the signal processing circuit based on the single-ended signal source.

[0092] In other words, in the corresponding Figure 8 In the signal processing circuit based on the single-ended signal source, the signal processing circuit based on the single-ended signal source further uses the analog-to-digital conversion unit 30 to digitally sample the signal output by the instrumentation amplifier 20, and preferably uses an existing IC chip that integrates an instrumentation amplifier circuit and an analog-to-digital conversion unit to directly connect to both ends of the sampling resistor 122 to form the signal processing circuit based on the single-ended signal source.

[0093] It is worth mentioning that when the instrumentation amplifier circuit is integrated into the IC chip as a programmable gain amplifier (PGA) using an instrumentation amplifier architecture, such as, but not limited to, the IC chips provided by Chipsea Technologies (models CS1237 and CS1259B), the IC chip provided by Chipsea Technologies (model SC2945), the IC chip provided by Sanbang Microelectronics (model SGM58201), and the IC chips provided by Texas Instruments (models ADS1260, ADS1261, ADS1220, ADS1246, ADS1247, and ADS1248), the IC chips are suitable for this purpose. The IC chip AS1412 provided by Atomic Semiconductor and the IC chip PMD040 provided by Yingguang Technology, based on the advantages of adjustable gain and good linearity of the programmable gain amplifier with instrumentation amplifier architecture, are connected to the two ends of the sampling resistor 122 to amplify the original signal of the single-ended signal output by the single-ended signal source 11. This can simultaneously take into account the effective detection of strong and weak signals, thus ensuring the adaptability and reliability of the signal processing circuit based on the single-ended signal source in different application scenarios.

[0094] It is worth mentioning that the existing programmable gain amplifiers (PGAs) with instrumentation amplifier architecture are not used for signal processing of the single-ended signal source, nor are they used for signal processing of pyroelectric infrared sensing circuits, microwave sensing modules based on the Doppler effect, or ultrasonic detection sensors. Instead, they are used to amplify the output differential signal of sensing circuits that can generate differential signal outputs, such as the sensing circuits inside high-precision electronic scales and temperature sensors that can generate differential signal outputs.

[0095] In particular, in some embodiments of the present invention, when the IC chip corresponds to Figure 10When the multiplexer (MUX) configuration provides multiple input selection functionality, the two ends of the sampling resistor 122 are selectively connected to the two differential input terminals of a programmable gain amplifier using an instrumentation amplifier architecture via the corresponding input terminals of the multiplexer. Correspondingly, when the IC chip is applied to the signal processing circuit based on a single-ended signal source, it can also be matched with multiple dual-ended output circuits 10 based on single-ended signal sources. Furthermore, the types of single-ended signal sources 11 in each dual-ended output circuit 10 based on a single-ended signal source are not limited to the same. For example, at least one single-ended signal source 11 can be configured as a pyroelectric infrared sensing circuit and at least one single-ended signal source can be configured as a microwave sensing module based on the Doppler effect principle to achieve dual-technology detection. This avoids the problem of excessive power consumption by avoiding multiple amplification. The configuration of multiple dual-ended output circuits 10 based on single-ended signal sources in the signal processing circuit based on a single-ended signal source simplifies the circuit architecture of the signal processing circuit based on a single-ended signal source.

[0096] Correspondingly, in the above embodiments of the present invention, the single-ended signal source 11 can be configured as a pyroelectric infrared sensing circuit, or as the pyroelectric infrared sensing probe in the infrared sensing circuit with the pyroelectric infrared sensing probe set, or as a microwave sensing module based on the Doppler effect principle, or as an ultrasonic detection sensor. The present invention does not limit this.

[0097] Furthermore, in some embodiments of the present invention, the IC chip in Figure 8 or Figure 10 Based on the structure of the signal processing circuit based on the single-ended signal source shown, a microcontroller unit (MCU) can be further integrated, for example in... Figure 10 Based on the structure of the signal processing circuit based on the single-ended signal source shown in the diagram, corresponding to... Figure 11 The microcontroller unit 40 is further integrated. The microcontroller unit 40 is used to receive the signal output by the analog-to-digital converter unit 30 for analysis and judgment. The corresponding IC chip can also be an existing IC chip that integrates a programmable gain amplifier with an instrumentation amplifier architecture, the analog-to-digital converter unit 30, and the microcontroller unit 40. For example, but not limited to, the LH32M0XX series and LH32M3XX series IC chips provided by Leadcore Technology, the TMS320F28053 IC chip provided by Texas Instruments, and the TCHV4018L IC chip provided by Taisilicon. The present invention does not limit this.

[0098] It is worth mentioning that, for the independent microcontroller unit 40, the microcontroller unit 40 itself may integrate the analog-to-digital converter unit 30. Corresponding to the state in which the microcontroller unit 40 is integrated into the IC chip, the IC chip still conforms to the description of simultaneously integrating a programmable gain amplifier using an instrumentation amplifier architecture, the analog-to-digital converter unit 30, and the microcontroller unit 40. The present invention does not limit this.

[0099] It will be understood by those skilled in the art that the above embodiments are merely examples, and features of different embodiments can be combined with each other to obtain implementation methods that are readily conceivable according to the content disclosed in the present invention but are not explicitly shown in the accompanying drawings.

[0100] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and explained in the embodiments, and any variations or modifications may be made to the implementation of the present invention without departing from the stated principles.

Claims

1. A dual-ended output circuit based on a single-ended signal source, wherein the dual-ended output circuit based on the single-ended signal source is used to match the two input terminals of an instrumentation amplifier for differential input to have a dual-ended output, characterized in that, include: A single-ended signal source, the single-ended signal source being configured to output a raw signal in a single-ended signal form at its output terminal when powered; and An RC sampling circuit includes a pair of ground capacitors and a sampling resistor. One end of the ground capacitor is grounded, and the other end of the ground capacitor is electrically connected to the sampling resistor. The end of the sampling resistor opposite to the end connected to the ground capacitor is electrically connected to the output terminal of the single-ended signal source. The dual-ended output circuit based on the single-ended signal source forms a dual-ended output with the two ends of the sampling resistor as output terminals. The time constant of the RC sampling circuit is less than or equal to 1.5s.

2. The dual-ended output circuit based on a single-ended signal source according to claim 1, wherein the dual-ended output circuit based on a single-ended signal source further includes a first resistor and a first capacitor, wherein the single-ended signal source is electrically connected to the sampling resistor via the first resistor, one end of the first resistor electrically connected to the sampling resistor is further connected to one end of the first capacitor, and the other end of the first capacitor is grounded.

3. The dual-ended output circuit based on a single-ended signal source according to claim 2, wherein the dual-ended output circuit based on a single-ended signal source further includes a second capacitor, wherein the second capacitor is connected in parallel with the sampling resistor.

4. The dual-ended output circuit based on a single-ended signal source according to claim 3, wherein the sampling resistor is electrically connected to the ground capacitor via a second resistor.

5. The dual-ended output circuit based on a single-ended signal source according to claim 1, wherein the dual-ended output circuit based on a single-ended signal source further includes a second capacitor, wherein the second capacitor is connected in parallel with the sampling resistor.

6. The dual-ended output circuit based on a single-ended signal source according to claim 1, wherein the sampling resistor is electrically connected to the ground capacitor via a second resistor.

7. The dual-ended output circuit based on a single-ended signal source according to claim 6, wherein the dual-ended output circuit based on a single-ended signal source further includes a first resistor and a first capacitor, wherein the single-ended signal source is electrically connected to the sampling resistor via the first resistor, one end of the first resistor electrically connected to the sampling resistor is further connected to one end of the first capacitor, and the other end of the first capacitor is grounded.

8. The dual-ended output circuit based on a single-ended signal source according to claim 6, wherein the dual-ended output circuit based on a single-ended signal source further includes a second capacitor, wherein the second capacitor is connected in parallel with the sampling resistor.

9. The dual-ended output circuit based on a single-ended signal source according to any one of claims 1 to 8, wherein the single-ended signal source is configured as a pyroelectric infrared sensing circuit.

10. The dual-ended output circuit based on a single-ended signal source according to claim 9, wherein the infrared sensing circuit is configured in the form of a pyroelectric infrared sensing probe and has a power supply terminal for connecting to a power source, a signal output terminal for outputting the original signal in an analog form, and a grounding terminal for grounding.

11. The dual-ended output circuit based on a single-ended signal source according to claim 10, wherein the power supply terminal is connected to the power supply via at least one stage of filter circuit, the filter circuit is designed as a series RC circuit and the end of the series RC circuit opposite to the end connected in series with capacitor C is connected to the power supply as the input terminal, and the end of the resistor R connected in series with capacitor C is the output terminal, and the end of capacitor C opposite to the end connected in series with resistor R is grounded.

12. The dual-ended output circuit based on a single-ended signal source according to any one of claims 1 to 8, wherein the single-ended signal source is configured as a microwave sensing module based on the Doppler effect principle.

13. The dual-ended output circuit based on a single-ended signal source according to any one of claims 1 to 8, wherein the single-ended signal source is configured as an ultrasonic detection sensor.

14. A signal processing circuit based on a single-ended signal source, characterized in that, include: A single-ended signal source, the single-ended signal source being configured to output a raw signal in a single-ended signal form at its output terminal when powered; An RC sampling circuit includes a pair of ground capacitors and a sampling resistor. One end of the ground capacitor is grounded, and the other end of the ground capacitor is electrically connected to the sampling resistor. The end of the sampling resistor opposite to the end connected to the ground capacitor is electrically connected to the output terminal of the single-ended signal source. as well as An instrumentation amplifier, wherein the two ends of the sampling resistor are the output terminals, and the instrumentation amplifier is used to amplify the signals output from the two output terminals.

15. The signal processing circuit based on a single-ended signal source according to claim 14, wherein the single-ended signal source is configured as a pyroelectric infrared sensing circuit.

16. The signal processing circuit based on a single-ended signal source according to claim 14, wherein the single-ended signal source is configured as a microwave sensing module based on the Doppler effect principle.

17. The signal processing circuit based on a single-ended signal source according to claim 14, wherein the single-ended signal source is configured as an ultrasonic detection sensor.

18. The signal processing circuit based on a single-ended signal source according to any one of claims 14 to 17, wherein the signal processing circuit based on the single-ended signal source further performs digital sampling of the signal output by the instrumentation amplifier using an analog-to-digital conversion unit.

19. The signal processing circuit based on a single-ended signal source according to claim 18, wherein the instrumentation amplifier circuit and the analog-to-digital converter unit are integrated into an IC chip.

20. The signal processing circuit based on a single-ended signal source according to claim 19, wherein the instrumentation amplifier circuit is integrated in the IC chip as a programmable gain amplifier employing an instrumentation amplifier architecture.

21. The signal processing circuit based on a single-ended signal source according to claim 20, wherein the IC chip further integrates a microcontroller unit, the microcontroller unit being used to access the signal output by the analog-to-digital conversion unit to analyze and judge the signal.

22. The signal processing circuit based on a single-ended signal source according to claim 20, wherein the IC chip further integrates a multiplexer to have a multiplexed input function, wherein the number of dual-ended output circuits based on the single-ended signal source, which are composed of the single-ended signal source and the RC sampling circuit, is multiple, and the two ends of the sampling resistor of each dual-ended output circuit based on the single-ended signal source are selectively connected to the two input terminals of a programmable gain amplifier with an instrumentation amplifier architecture for differential input via the corresponding input terminals of the multiplexer.

23. The signal processing circuit based on a single-ended signal source according to claim 22, wherein in the plurality of dual-ended output circuits based on single-ended signal sources, at least one of the single-ended signal sources is configured as a pyroelectric infrared sensing circuit and at least one of the single-ended signal sources is configured as a microwave sensing module based on the Doppler effect principle.

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