Detection circuit and detection method of level signal

Abstract

The embodiment of the invention provides a level signal detection circuit and detection method. The level signal detection circuit comprises a first detection module and a second detection module which are respectively connected with a control module, a first diode in the first detection module is connected with a second switch unit through a first switch unit, a first end of a first switch tube is connected with a to-be-detected level signal, and an output end of the second switch unit is connected with the control module; a ninth voltage-regulator tube in the second detection module is connected with a fourth switch unit through a third switch unit, the input end of the ninth voltage-regulator tube is connected with a to-be-detected level signal, and the output end of the fourth switch unit is connected with the control module; the control module is used for determining the type of the level signal to be detected according to the first output signal and the second output signal, a complex integrated circuit is not needed, detection of different signals is achieved only through simple discrete components, and the device has the advantages of being high in reliability, low in cost, low in software complexity and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit detection, in particular to a level signal detection circuit and a detection method. BACKGROUND

[0002] In the automotive electronics, there are various sensors and ECUs (Engine Control Unit, engine control module) distributed, and generally, the sensor outputs a digital level signal to the ECU to realize various function detection. According to the purpose and characteristics of the sensor, the sensor output level signal is divided into low level effective, high level effective, suspended effective, etc. For different types of level signals, the ECU needs to have different detection circuits to realize the detection of the signal. In the existing automotive electronics technology, the ECU will plan the corresponding detection circuit according to the signal type and the number determined in advance during the development stage, and this way will cause the sensor signal type to change later, and the related hardware circuit of the ECU has to be redesigned, which has a great impact on the development cycle of the project. SUMMARY

[0003] Some embodiments of the present application aim to provide a level signal detection circuit and a detection method. Through the technical solutions of the embodiments of the present application, the level signal detection circuit comprises a first detection module and a second detection module, the first detection module and the second detection module are connected with a control module respectively; the first detection module comprises a first diode, a first switch unit and a second switch unit, the first diode is connected through the first switch unit and the second switch unit, a first end of the first diode is connected with a level signal to be detected, an output end of the second switch unit is connected with the control module; the second detection module comprises a ninth voltage stabilizing tube, a third switch unit and a fourth switch unit, the ninth voltage stabilizing tube is connected through the third switch unit and the fourth switch unit, an input end of the ninth voltage stabilizing tube is connected with the level signal to be detected, an output end of the fourth switch unit is connected with the control module; the control module is used for determining the type of the level signal to be detected according to a first output signal of the output end of the second switch unit and a second output signal of the output end of the fourth switch unit, the type of the level signal to be detected at least includes high level signal effective, low level signal effective or suspended signal effective, the level signal detection circuit provided by the embodiments of the present application does not need a complex integrated circuit, and only through simple discrete components, the detection of the low effective signal, the high effective signal and the suspended effective signal can be realized, and the level signal detection circuit has the advantages of high reliability, low cost, low software complexity, etc.

[0004] In a first aspect, some embodiments of the present application provide a detection circuit of a level signal, comprising: a first detection module and a second detection module, the first detection module and the second detection module are connected with a control module respectively; The first detection module comprises a first diode, a first switch unit and a second switch unit, the first diode is connected with the first switch unit and the second switch unit, a first end of the first diode is connected with a level signal to be detected, and an output end of the second switch unit is connected with the control module. The second detection module comprises a ninth voltage stabilizing tube, a third switch unit and a fourth switch unit, the ninth voltage stabilizing tube is connected with the third switch unit and the fourth switch unit, an input end of the ninth voltage stabilizing tube is connected with the level signal to be detected, and an output end of the fourth switch unit is connected with the control module. The control module is configured to determine a type of the level signal to be detected according to a first output signal of the output end of the second switch unit and a second output signal of the output end of the fourth switch unit, and the type of the level signal to be detected at least comprises a high level signal effective, a low level signal effective or a suspended signal effective.

[0005] Some embodiments of the present application can realize the detection of low effective signal, high effective signal and suspended effective signal by the detection circuit of the level signal provided, without complex integrated circuits, only through simple discrete components, and have the advantages of high reliability, low cost and low software complexity.

[0006] Optionally, the first switch unit comprises a first resistor, a second resistor, a third switch tube, a first voltage source, a third resistor and a fourth resistor, wherein: a first end of the first resistor is connected with a second end of the first diode, a second end of the first resistor is connected with a first end of the second resistor, and a second end of the second resistor is connected with the first voltage source. A first end of the second resistor is connected with a base of the third switch tube, an emitter of the third switch tube is connected with a second end of the second resistor, a collector of the third switch tube is connected with the ground through the third resistor, and the collector of the third switch tube is also connected with a first end of the fourth resistor. Optionally, the second switch unit comprises a fifth resistor, a sixth resistor, a seventh resistor, a fourth switch tube and a second voltage source, wherein: A second end of the fourth resistor is connected with a first end of the fifth resistor, a second end of the fifth resistor is connected with an emitter of the fourth switch tube and the ground, a first end of the fifth resistor is connected with a base of the fourth switch tube, a collector of the fourth switch tube is connected with the second voltage source through the sixth resistor, and the collector of the fourth switch tube is connected with the control module through the seventh resistor. Optionally, the third switch unit comprises a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fifth switch tube and a third voltage source, wherein: The second end of the ninth voltage stabilizing tube is connected with the first end of the tenth resistor, the second end of the tenth resistor is connected with the first end of the eleventh resistor and the base of the fifth switch tube respectively, the second end of the eleventh resistor and the emitter of the fifth switch tube are connected with the ground, the collector of the fifth switch tube is connected with the third voltage source through the twelfth resistor, and the collector of the fifth switch tube is connected with the first end of the thirteenth resistor.

[0007] Optionally, the fourth switch unit comprises a fourteenth resistor, a fifteenth resistor, an eighteenth resistor, a seventh switch tube and a fifth voltage source, wherein: The second end of the thirteenth resistor is connected with the first end of the eighteenth resistor and the base of the seventh switch tube respectively, the second end of the eighteenth resistor is connected with the fifth voltage source, the emitter of the seventh switch tube is connected with the fifth voltage source, the collector of the seventh switch tube is connected with the first end of the fifteenth resistor and the first end of the fourteenth resistor respectively, and the second end of the fifteenth resistor is connected with the control module.

[0008] Some embodiments of the present application provide a level signal detection circuit, which does not need complex integrated circuits, but only needs simple discrete components to detect low active signals, high active signals and suspended active signals, and has the advantages of high reliability, low cost and low software complexity.

[0009] Optionally, the third switch tube, the fourth switch tube, the fifth switch tube and the seventh switch tube are triodes.

[0010] In a second aspect, some embodiments of the present application provide a level signal detection method, applied to the level signal detection circuit of any one of the first aspect, comprising: obtaining a first output signal and a second output signal; judging the first output signal and the second output signal; determining the type of the level signal to be detected according to the judgment result, wherein the type of the level signal to be detected at least includes high level signal active, low level signal active or suspended signal active.

[0011] Optionally, the determination of the type of the level signal to be detected according to the judgment result comprises: if the first output signal and the second output signal are both high level, it is determined that the type of the level signal to be detected is high level signal active.

[0012] Optionally, the type of the level signal to be detected is determined according to the judgment result, and the determining comprises: If the first output signal and the second output signal are both low level, it is determined that the type of the level signal to be detected is low level signal effective.

[0013] Optionally, the type of the level signal to be detected is determined according to the judgment result, and the determining comprises: If the levels of the first output signal and the second output signal are different, it is determined that the type of the level signal to be detected is suspended signal effective.

[0014] Some embodiments of the present application provide a level signal detection circuit, a control module acquires output signals of a first detection module and a second detection module, judges the two signals, and determines the type of the level signal to be detected, so that the detection of low effective signal, high effective signal and suspended effective signal can be realized by simple discrete components without complex integrated circuits, and the level signal detection circuit has the advantages of high reliability, low cost and low software complexity. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of some embodiments of the present application, the following will briefly introduce the drawings needed to be used in some embodiments of the present application. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0016] Figure 1 A structural block diagram of a level signal detection circuit provided by some embodiments of the present application is shown in the figure. Figure 2 A schematic diagram of a level signal detection circuit provided by some embodiments of the present application is shown in the figure. DETAILED DESCRIPTION

[0017] The technical solutions of some embodiments of the present application will be described below in combination with the drawings in some embodiments of the present application.

[0018] It should be noted that similar labels and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of the present application, the terms "first", "second" and the like are only used for distinguishing description, and cannot be understood as indicating or implying relative importance.

[0019] In the automobile electronics, various sensors and ECUs are distributed, and generally, the sensor outputs digital level signals to the ECU to realize various function detection. Generally, according to the sensor use and characteristics, the sensor output level signal is divided into low level effective, high level effective, suspended effective and the like. For different level signal types, the ECU needs to have different detection circuits to realize the signal detection. In the existing automobile electronic technology, the ECU will plan the corresponding detection circuit according to the signal type and quantity determined in advance in the development stage, and this way will cause the sensor signal type to change in the later stage, and the related hardware circuit of the ECU has to be redesigned, which has a great influence on the development cycle of the project. In view of this, some embodiments of the present application provide a level signal detection circuit, which comprises: a first detection module and a second detection module, the first detection module and the second detection module are connected with a control module respectively; the first detection module comprises a first diode, a first switch unit and a second switch unit, the first diode is connected through the first switch unit and the second switch unit, a first end of the first diode is connected with a level signal to be detected, an output end of the second switch unit is connected with the control module; the second detection module comprises a ninth voltage stabilizing tube, a third switch unit and a fourth switch unit, the ninth voltage stabilizing tube is connected through the third switch unit and the fourth switch unit, an input end of the ninth voltage stabilizing tube is connected with the level signal to be detected, an output end of the fourth switch unit is connected with the control module; the control module is used for determining the type of the level signal to be detected according to a first output signal of the output end of the second switch unit and a second output signal of the output end of the fourth switch unit, the type of the level signal to be detected at least comprises a high level signal effective, a low level signal effective or a suspended signal effective, the level signal detection circuit provided by the embodiments of the present application does not need a complex integrated circuit, and only through simple discrete components, the detection of low effective signal, high effective signal and suspended effective signal can be realized, and has the advantages of high reliability, low cost, low software complexity and the like.

[0020] As shown in Figure 1 the embodiments of the present application provide a level signal detection circuit, which comprises: a first detection module 10 and a second detection module 20, the first detection module 10 and the second detection module 20 are connected with a control module 30 respectively; the first detection module 10 comprises a first diode 101, a first switch unit 102 and a second switch unit 103, the first diode 101 is connected through the first switch unit 102 and the second switch unit 103, a first end of the first diode 101 is connected with a level signal to be detected, an output end of the second switch unit is connected with the control module; The second detection module 20 includes a ninth Zener diode 201, a third switching unit 202, and a fourth switching unit 203. The ninth Zener diode 201 is connected to the fourth switching unit 203 through the third switching unit 202. The input terminal of the ninth Zener diode 201 is connected to the level signal to be detected. The output terminal of the fourth switching unit 203 is connected to the control module 30. The control module 30 is used to determine the type of the level signal to be detected based on the first output signal of the output terminal of the second switch unit 103 and the second output signal of the output terminal of the fourth switch unit 203. The type of the level signal to be detected includes at least high level signal valid, low level signal valid, or floating signal valid.

[0021] The control module 30 can be an MCU (Microcontroller Unit) chip or a SOC (System on Chip) chip.

[0022] Some embodiments of this application, through the provided level signal detection circuit, can realize the detection of low active signals, high active signals, and floating active signals using only simple discrete components without complex integrated circuits, and have the advantages of high reliability, low cost, and low software complexity.

[0023] Another embodiment of this application further explains the detection circuit for the level signal provided in the above embodiments.

[0024] like Figure 2 As shown, optionally, the first switching unit includes a first resistor R1, a second resistor R2, a third switching transistor U3, a first voltage source V1, a third resistor R3, and a fourth resistor R4, wherein: the first end of the first resistor R1 is connected to the second end of the first diode U1, the second end of the first resistor R1 is connected to the first end of the second resistor R2, and the second end of the second resistor R2 is connected to the first voltage source V1. The first end of the second resistor R2 is connected to the base of the third switch U3. The emitter of the third switch U3 is connected to the second end of the second resistor R2. The collector of the third switch U3 is connected to ground through the third resistor R3. The collector of the third switch U3 is also connected to the first end of the fourth resistor R4. Optionally, the second switching unit includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a fourth switching transistor U4, and a second voltage source V2, wherein: The second end of the fourth resistor R4 is connected with the first end of the fifth resistor R5, the second end of the fifth resistor R5 is connected with the emitter of the fourth switch tube U4 and the ground, the first end of the fifth resistor R5 is connected with the base of the fourth switch tube U4, the collector of the fourth switch tube U4 is connected with the second voltage source V2 through the sixth resistor R6, and the collector of the fourth switch tube U4 is connected with the control module 30 through the seventh resistor R7. Optionally, the third switch unit comprises a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fifth switch tube U5 and a third voltage source V3, wherein: The second end of the ninth voltage stabilizing tube U9 is connected with the first end of the tenth resistor R10, the second end of the tenth resistor R10 is connected with the first end of the eleventh resistor R11 and the base of the fifth switch tube U5 respectively, the second end of the eleventh resistor R11 and the emitter of the fifth switch tube U5 are connected with the ground, the collector of the fifth switch tube U5 is connected with the third voltage source V3 through the twelfth resistor R12, and the collector of the fifth switch tube U5 is connected with the first end of the thirteenth resistor R13.

[0025] Optionally, the fourth switch unit comprises a fourteenth resistor R14, a fifteenth resistor R15, an eighteenth resistor R18, a seventh switch tube U7 and a fifth voltage source V5, wherein: The second end of the thirteenth resistor R13 is connected with the first end of the eighteenth resistor R18 and the base of the seventh switch tube U7 respectively, the second end of the eighteenth resistor R18 is connected with the fifth voltage source V5, the emitter of the seventh switch tube U7 is connected with the fifth voltage source V5, the collector of the seventh switch tube U7 is connected with the first end of the fifteenth resistor R15 and the first end of the fourteenth resistor R14 respectively, and the second end of the fifteenth resistor R15 is connected with the control module 30.

[0026] The level signal detection circuit provided by some embodiments of the present application does not need complex integrated circuits, and can realize detection of low active signals, high active signals and suspended active signals through simple discrete components, and has the advantages of high reliability, low cost and low software complexity.

[0027] Optionally, the third switch tube U3, the fourth switch tube U4, the fifth switch tube U5 and the seventh switch tube U7 are triodes.

[0028] It should be noted that the various implementable manners in the present embodiment can be implemented alone or in any combination without conflict.

[0029] Another embodiment of the present application provides a level signal detection method, which is used to execute the detection circuit of the level signal provided by the above-mentioned embodiment.

[0030] The forward conduction voltage V F of the Schottky diode U1 used in the embodiment of the present application is 0.7V, the reverse breakdown voltage V Z of the zener diode U9 is 6.8V, and the voltage difference between the base and the collector of the triode is 0.7V when the triode is turned on.

[0031] Case 1: the input Vin is low level; Suppose that the triode U3 is in the on state, at this time, the voltage V EB between the collector and the base of the triode U3 is 0.7V, and I EB is the collector-to-base current. For the node current of the base of U3, according to the Kirchhoff's current law, the following relationship is obtained: Since the triode is in the on state, I EB > 0, thus the following is obtained:

[0032] After the parameters are brought in for calculation, it is obtained that Vin < 3.593V.

[0033] For U4, the base voltage is pulled up, so that U4 is in the on state, V out1 is pulled down to the ground through the resistor R7, so that V out1 is 0V. For the triode U5, since the zener diode U9 is in the reverse off state, U5 and U7 are in the off state at the same time, so V out2 is pulled down to the ground, and the voltage is 0V.

[0034] Case 2: the input Vin is high level Suppose that the triode U5 is in the on state, at this time, the voltage V BE between the collector and the base of U5 is 0.7V, and I EB is the collector-to-base current. For the node current of the base of U5, according to the Kirchhoff's current law, the following relationship is obtained:

[0035] Since the triode is in the on state, I BE > 0, thus the following is obtained:

[0036] After the parameters are brought in for calculation, it is obtained that V in > 7.507V.

[0037] For U7, the base voltage is pulled down to the ground, so that U7 is in the on state, V​out2 R 15 The resistance is pulled up to the power supply V5, so V out2 The voltage is 3.3V. For the transistor U3, since the diode U1 is reverse-biased, U3 and U4 are both in the off state, so the Vout1 voltage is pulled up to the power supply V2, and the voltage is 3.3V.

[0038] Case 3: the Vin signal is suspended At this time, the V1 power supply is input to the positive electrode of the U9 zener diode through R2, R1, and U1. Since the V1 power supply 5V is less than the reverse breakdown voltage 6.8V of the zener diode, U9 is not conducting. Therefore, U3 and U4 are in the off state, and V out1 The signal is pulled up to V2 voltage, V out1 =3.3V. Similarly, U5 and U7 are also in the off state, and V out2 The signal is pulled down to ground, V out2 =0V.

[0039] According to the above design principle, a level signal detection method can be obtained, which is applied to the above-mentioned level signal detection circuit, comprising: Obtaining a first output signal and a second output signal; Judging the first output signal and the second output signal; According to the judgment result, the type of the level signal to be detected is determined, and the type of the level signal to be detected at least includes high-level signal effective, low-level signal effective or suspended signal effective.

[0040] That is, based on the above-mentioned level signal detection circuit, without knowing the type of the level signal Vin to be detected, through the detection circuit of the present application, there is a first output signal in the second switch unit, and a second output signal in the fourth switch unit, and the first output signal and the second output signal are input to the control module, the control module judges the first output signal and the second output signal, and obtains the type of the level signal to be detected, which at least includes high-level signal effective, low-level signal effective or suspended signal effective.

[0041] Further, the type of the level signal to be detected is determined according to the judgment result, comprising: If the first output signal and the second output signal are both high, it is determined that the type of the level signal to be detected is high-level signal effective.

[0042] Alternatively, the type of the level signal to be detected is determined according to the judgment result, comprising: If the first output signal and the second output signal are both low, it is determined that the type of the level signal to be detected is low-level signal effective.

[0043] Optionally, the type of the level signal to be detected is determined according to the determination result, including: If the levels of the first output signal and the second output signal are different, it is determined that the type of the level signal to be detected is a suspended signal.

[0044] The level signal detection circuit of the present application mainly includes triodes, diodes, resistors and other devices, wherein Vin is an input signal, i.e., a level to be detected, Vout1 and Vout2 are output signals, the level of the Vin signal is judged by detecting the levels of the Vout1 and Vout2 signals, and the judgment method is shown in Table 1: Table 1

[0045] Some embodiments of the present application provide a level signal detection circuit, a control module acquires output signals of a first detection module and a second detection module, judges two signals, and determines the type of the level signal to be detected. In this way, without complex integrated circuits, only simple discrete components can realize the detection of low active signals, high active signals and suspended active signals, and have the advantages of high reliability, low cost, low software complexity, etc.

[0046] The present application provides a kind of automobile electronic level signal detection circuit and method, without complex integrated circuit, only by simple discrete component, it can realize the detection of low active signal, high active signal and suspended active signal.It has the advantages of high reliability, low cost, low software complexity, etc.Using this patent scheme, the re-development of ECU when the input level signal type changes can be avoided, and the product development cycle can be shortened, saving costs for enterprises.

[0047] As to the device in the present embodiment, the specific manner in which each module performs operations has been described in detail in the embodiments relating to the method, and will not be described in detail here.

[0048] The above is only an embodiment of the present application and does not limit the protection scope of the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application. It should be noted that similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0049] The above description is merely exemplary in nature of the technical solutions of the present application, but the scope of protection of the present application is not limited thereto. Any modification or replacement within the technical scope disclosed by the present application should be covered within the scope of protection of the present application. Therefore, the scope of protection of the present application should be subject to the scope of protection of the claims.

[0050] It should be noted that the relative terms such as first and second, and the like, are used herein only to differentiate one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between such entities or operations. Moreover, the terms "comprising", "including", or any other variant thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the statement "comprising a" does not exclude the existence of additional identical elements in the process, method, article, or apparatus that includes the element.

Claims

1. A level signal detection circuit, characterized in that, The level signal detection circuit includes: a first detection module and a second detection module, wherein the first detection module and the second detection module are respectively connected to the control module; The first detection module includes a first diode, a first switching unit, and a second switching unit. The first diode is connected to the first switching unit and the second switching unit. The first terminal of the first diode is connected to the level signal to be detected. The output terminal of the second switching unit is connected to the control module. The second detection module includes a ninth Zener diode, a third switching unit, and a fourth switching unit. The ninth Zener diode is connected to the fourth switching unit through the third switching unit. The input terminal of the ninth Zener diode is connected to the level signal to be detected, and the output terminal of the fourth switching unit is connected to the control module. The control module is used to determine the type of the level signal to be detected based on the first output signal at the output terminal of the second switch unit and the second output signal at the output terminal of the fourth switch unit. The type of the level signal to be detected includes at least a high-level signal valid, a low-level signal valid, or a floating signal valid.

2. The level signal detection circuit according to claim 1, characterized in that, The first switching unit includes a first resistor, a second resistor, a third switching transistor, a first voltage source, a third resistor, and a fourth resistor, wherein: the first end of the first resistor is connected to the second end of the first diode, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the first voltage source; The first end of the second resistor is connected to the base of the third switch, the emitter of the third switch is connected to the second end of the second resistor, the collector of the third switch is connected to ground through the third resistor, and the collector of the third switch is also connected to the first end of the fourth resistor.

3. The level signal detection circuit according to claim 2, characterized in that, The second switching unit includes a fifth resistor, a sixth resistor, a seventh resistor, a fourth switching transistor, and a second voltage source, wherein: The second end of the fourth resistor is connected to the first end of the fifth resistor. The second end of the fifth resistor is connected to the emitter of the fourth switch and to ground. The first end of the fifth resistor is connected to the base of the fourth switch. The collector of the fourth switch is connected to the second voltage source through the sixth resistor. The collector of the fourth switch is connected to the control module through the seventh resistor.

4. The level signal detection circuit according to claim 3, characterized in that, The third switching unit includes: a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fifth switching transistor, and a third voltage source, wherein: The second terminal of the ninth Zener diode is connected to the first terminal of the tenth resistor. The second terminal of the tenth resistor is connected to the first terminal of the eleventh resistor and the base of the fifth switch. The second terminal of the eleventh resistor and the emitter of the fifth switch are connected to ground. The collector of the fifth switch is connected to the third voltage source through the twelfth resistor. The collector of the fifth switch is connected to the first terminal of the thirteenth resistor.

5. The level signal detection circuit according to claim 4, characterized in that, The fourth switching unit includes: a fourteenth resistor, a fifteenth resistor, an eighteenth resistor, a seventh switching transistor, and a fifth voltage source, wherein: The second end of the thirteenth resistor is connected to the first end of the eighteenth resistor and the base of the seventh switch, the second end of the eighteenth resistor is connected to the fifth voltage source, the emitter of the seventh switch is connected to the fifth voltage source, the collector of the seventh switch is connected to the first end of the fifteenth resistor and the first end of the fourteenth resistor, and the second end of the fifteenth resistor is connected to the control module.

6. The level signal detection circuit according to claim 5, characterized in that, The third, fourth, fifth, and seventh switching transistors are triodes.

7. A method for detecting a level signal, characterized in that, The method, applied to a level signal detection circuit as described in any one of claims 1-6, comprises: Obtain the first output signal and the second output signal; The first output signal and the second output signal are judged; Based on the judgment result, the type of the level signal to be detected is determined. The type of the level signal to be detected includes at least a high level signal valid, a low level signal valid, or a floating signal valid.

8. The method for detecting a level signal according to claim 7, characterized in that, The step of determining the type of the level signal to be detected based on the comparison result includes: If both the first output signal and the second output signal are at a high level, the type of the level signal to be detected is determined to be a valid high-level signal.

9. The method for detecting level signals according to claim 7, characterized in that, The step of determining the type of the level signal to be detected based on the comparison result includes: If both the first output signal and the second output signal are at a low level, the type of the level signal to be detected is determined to be a valid low-level signal.

10. The method for detecting a level signal according to claim 7, characterized in that, The step of determining the type of the level signal to be detected based on the comparison result includes: If the levels of the first output signal and the second output signal are different, the type of the level signal to be detected is determined to be a floating signal valid.

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