Switching tube state detection circuit, step-down circuit, detection method and electronic equipment

Abstract

The invention provides a switching tube state detection circuit, a step-down circuit, a detection method and electronic equipment. The switching tube state detection circuit comprises a switching state detection module and a processing module. The detection end of the switch state detection module is connected with a branch communicated with the switch tube, the output end of the switch state detection module is connected with the first input end of the processing module, and the second input end of the processing module is connected with the control chip. The switch state detection module is arranged to detect the specific switch condition of the switch tube, so that the processing module can compare the driving signal output by the control chip with the switch state of the switch tube, thereby determining whether the switch is abnormal or not, and performing indication based on the specific judgment result. Therefore, a user can determine the on-off state based on the indication, and when an abnormality occurs, the abnormality can be checked as soon as possible.

Description

Technical Field

[0001] The present invention relates to the electrical field, and in particular to a switch tube state detection circuit, a step-down circuit, a detection method and an electronic device. Background Art

[0002] Current voltage conversion circuits, such as BUCK circuits, mainly achieve voltage conversion by controlling the charging and discharging of inductors and capacitors through high-speed switching of MOS tubes. The MOS tubes are switched based on the pulse width modulation (PWM) signal output by the control chip. When a circuit or MOS tube fails, the MOS tube cannot be switched according to the PWM signal, resulting in a deviation in voltage conversion. However, the prior art lacks a method for detecting the state of the MOS tube. Summary of the invention

[0003] The main purpose of the present invention is to provide a switch tube state detection circuit, a step-down circuit, a detection method and an electronic device, aiming to solve the problem of lack of a method for detecting the state of a MOS tube in the prior art.

[0004] To achieve the above-mentioned purpose, the present invention provides a switch tube state detection circuit, wherein the switch tube state detection circuit is connected to a switch tube and a control chip respectively, and the switch tube is switched by a driving signal output by the control chip; the switch tube state detection circuit comprises a switch state detection module and a processing module; the detection end of the switch state detection module is connected to a branch connected to the switch tube, the output end of the switch state detection module is connected to a first input end of the processing module, and the second input end of the processing module is connected to the control chip; wherein:

[0005] The switch state detection module is used to detect the switch state of the switch tube to obtain a switch state signal, and send the switch state signal to the processing module;

[0006] The processing module is used to obtain the switch state signal sent by the switch state detection module and the drive signal sent by the control chip to the switch tube, and to determine whether the switch state signal corresponds to the drive signal, obtain a determination result, and output an indication signal corresponding to the determination result.

[0007] Optionally, the switch state detection module includes a current sampling unit and a switch state determination unit; the detection end of the current sampling unit is connected to the branch connected to the switch tube, the output end of the current sampling unit is connected to the input end of the switch state determination unit, and the output end of the switch state determination unit serves as the output end of the switch state detection module; wherein:

[0008] The current sampling unit is used to detect the current of the branch connected to the switch tube to obtain a detection current, and send a detection voltage corresponding to the detection current to the switch state determination unit;

[0009] The switch state determination unit is used to determine the switch state of the switch tube according to the detection voltage to obtain a switch state signal, and send the switch state signal to the processing module.

[0010] Optionally, the switch state determination unit includes a comparator and a reference voltage subunit; the non-inverting input terminal of the comparator is used as the input terminal of the switch state determination unit, the inverting input terminal of the comparator is connected to the reference voltage subunit, and the output terminal of the comparator is used as the output terminal of the switch state determination unit; wherein:

[0011] The reference voltage subunit is used to provide a reference voltage, wherein when there is no current in the branch connected to the switch tube, the detection voltage output by the current sampling unit is the same as the reference voltage, and when there is current in the branch connected to the switch tube, the detection voltage output by the current sampling unit is greater than the reference voltage;

[0012] The comparator is used to compare the reference voltage with the detection voltage, and when the reference voltage is greater than or equal to the detection voltage, output a switch state signal indicating shutdown to the processing module, and when the reference voltage is less than the detection voltage, output a switch state signal indicating conduction to the processing module.

[0013] Optionally, the switch tube state detection circuit further includes an indication module, and the indication module includes a first resistor and a light emitting diode, wherein:

[0014] The positive electrode of the light emitting diode is connected to the output end of the processing module through the first resistor, and the negative electrode of the light emitting diode is grounded.

[0015] To achieve the above object, the present invention further provides a step-down circuit, which includes a switch tube, a control chip and the switch tube state detection circuit as described above.

[0016] Optionally, the step-down circuit further includes a first inductor, a first capacitor and a first diode, wherein:

[0017] The input end of the switch tube is connected to the power supply, the output end of the switch tube is connected to the first end of the first inductor, the first end of the first inductor is also connected to the cathode of the first diode, the anode of the first diode is grounded, the second end of the first inductor serves as the output end of the step-down circuit, and the second end of the first inductor is also grounded through the first capacitor.

[0018] To achieve the above object, the present invention further provides a switch tube state detection method, which is applied to a processing module in the switch tube state detection circuit as described above; the switch tube state detection method comprises:

[0019] Acquire a switch state signal sent by a switch state detection module and a drive signal sent by a control chip to a switch tube, wherein the switch state signal is obtained by detecting the switch state of the switch tube by the switch state detection module, and the switch tube is switched by the drive signal output by the control chip;

[0020] Determine whether the switch state signal corresponds to the drive signal, and obtain a determination result;

[0021] An indication signal corresponding to the judgment result is output.

[0022] Optionally, the determining whether the switch state signal corresponds to the drive signal to obtain a determination result includes:

[0023] Determine a switch state waveform corresponding to the switch state signal and a drive signal waveform corresponding to the drive signal;

[0024] For each driving cycle, determining a first duty cycle of the switch state waveform in the driving cycle and a second duty cycle of the drive signal waveform in the driving cycle;

[0025] Determining whether the first duty cycle is consistent with the second duty cycle;

[0026] If the first duty cycle is consistent with the second duty cycle, determining that the judgment result is that the switch tube is normal;

[0027] If the first duty cycle is inconsistent with the second duty cycle, it is determined that the judgment result is that the switch tube is abnormal.

[0028] Optionally, the outputting an indication signal corresponding to the judgment result includes:

[0029] Determining that the judgment result is that the switch tube is normal or the switch tube is abnormal;

[0030] If the judgment result is that the switch tube is abnormal, a high-level indication signal is sent to the indication module to light up the light-emitting diode in the indication module;

[0031] If the judgment result is that the switch tube is normal, a low-level indication signal is sent to the indication module so that the light-emitting diode in the indication module does not light up.

[0032] To achieve the above object, the present invention further provides an electronic device, wherein a computer program is stored on the electronic device, and when the computer program is executed by a processor, the steps of the switch tube state detection method as described above are implemented.

[0033] The present invention proposes a switch tube state detection circuit, a step-down circuit, a detection method and an electronic device, wherein the switch tube state detection circuit is connected to a switch tube and a control chip respectively, and the switch tube is switched by a drive signal output by the control chip; the switch tube state detection circuit comprises a switch state detection module, a processing module and an indication module; the detection end of the switch state detection module is connected to a branch connected to the switch tube, the output end of the switch state detection module is connected to a first input end of the processing module, the second input end of the processing module is connected to the control chip, and the output end of the processing module is connected to a control end of the indication module; wherein: the switch state detection module is used to detect the switch state of the switch tube to obtain a switch state signal, and send the switch state signal to the processing module; the processing module is used to obtain the switch state signal sent by the switch state detection module and the drive signal sent by the control chip to the switch tube, and judge whether the switch state signal corresponds to the drive signal, obtain a judgment result, and output an indication signal corresponding to the judgment result; the indication module is used to receive the indication signal sent by the processing module, and indicate the operating state of the switch tube according to the indication signal. By setting up a switch status detection module to detect the specific switch condition of the switch tube, the processing module can compare the drive signal output by the control chip with the switch status of the switch tube to determine whether a switch abnormality occurs, and output the specific judgment result so that the user can determine the switch status based on the indication. When an abnormality occurs, the abnormality can be checked as soon as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0036] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0037] Figure 1 It is a module structure diagram of the switch tube state detection circuit of the present invention;

[0038] Figure 2 It is a structural schematic diagram of the step-down circuit of the present invention;

[0039] Figure 3 It is a schematic diagram of the signal output of the current sensor in the switch tube state detection circuit of the present invention;

[0040] Figure 4 It is a schematic diagram of the flow chart of the first embodiment of the switch tube state detection method of the present invention;

[0041] Figure 5 Schematic diagram of signal waveform in the switch tube state detection method of the present invention;

[0042] Figure 6 It is a schematic diagram of the module structure of the electronic device of the present invention.

[0043] Description of Figure Numbers:

[0044] Label name Label name 110 Switch status detection module Q1 Switching tube 111 Current sampling unit B1 Comparator 112 Switch state determination unit R1 First resistor 1121 Reference voltage subunit led Light Emitting Diode 120 Processing Module D1 The first diode 130 Indicator module C1 First capacitor 210 Control chip L1 First Inductor DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0046] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0047] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only embodiments of a part of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work should fall within the scope of protection of the present application.

[0048] The present invention provides a switch tube state detection circuit, referring to Figure 1 , Figure 1 The module structure diagram of the first embodiment of the switch tube state detection circuit of the present invention; the switch tube state detection circuit is connected to the switch tube Q1 and the control chip 210, and the switch tube Q1 is switched by the driving signal output by the control chip 210; the switch tube state detection circuit includes a switch state detection module 110 and a processing module 120; the detection end of the switch state detection module 110 is connected to the branch connected to the switch tube Q1, the output end of the switch state detection module 110 is connected to the first input end of the processing module 120, and the second input end of the processing module 120 is connected to the control chip 210; wherein:

[0049] The switch state detection module 110 is used to detect the switch state of the switch tube Q1 to obtain a switch state signal, and send the switch state signal to the processing module 120;

[0050] The processing module 120 is used to obtain the switch state signal sent by the switch state detection module 110 and the drive signal sent by the control chip 210 to the switch tube Q1, and judge whether the switch state signal corresponds to the drive signal, obtain a judgment result, and output an indication signal corresponding to the judgment result.

[0051] First, it should be noted that the switch tube Q1 in the present application is applied to a voltage conversion circuit, which includes but is not limited to a buck circuit and a boost circuit; the switch tube Q1 is a MOS tube, and the control end of the switch tube Q1 is the gate of the MOS tube, which can be an NMOS tube or a PMOS tube; the control end of the switch tube Q1 is connected to the control chip 210, and the control chip 210 outputs a PWM signal, that is, a drive signal to the gate of the MOS tube to control the switching state of the MOS tube. In this embodiment, the switch tube Q1 is an NMOS and is applied to a buck circuit as an example for explanation. Other types of voltage conversion circuits can be implemented by analogy and will not be described in detail.

[0052] Under normal circumstances, the control chip 210 sends a PWM signal to the gate of the NMOS tube. When the PWM signal is at a high level, the NMOS tube is turned on, and when the PWM signal is at a low level, the NMOS tube is turned off. During the driving cycle, the duty cycle of the PWM signal is the same as the on-time of the NMOS tube.

[0053] When there is a problem with the circuit or MOS tube, the PWM signal may not be fully transmitted to the gate of the MOS tube, or the MOS tube may not be turned on or off completely according to the waveform of the PWM signal. At this time, during the driving cycle, the duty cycle of the PWM signal is different from the proportion of the conduction time of the NMOS tube.

[0054] It is understandable that when the MOS tube is turned on or off, the electrical signal state on the branch connected to the MOS tube is also different. Therefore, by setting the switch state detection module 110 to detect the branch connected to the MOS tube, the switch state of the MOS tube can be determined to obtain a switch state signal; the switch state signal indicates whether the switch state of the switch tube Q1 is on or off.

[0055] The processing module 120 obtains the switch state signal sent by the switch state detection module 110 and the PWM signal sent by the control chip 210 respectively; it can be understood that the switch state signal indicates the actual switch state of the switch tube Q1, and the PWM signal indicates the expected switch state of the switch tube Q1. Therefore, by comparing the switch state signal with the PWM signal, it can be determined whether the switch state of the switch tube Q1 matches the PWM signal output by the control chip 210, that is, whether the switch state signal corresponds to the drive signal; when the switch state signal corresponds to the drive signal, it is considered that the switch state of the switch tube Q1 is consistent with the current circuit requirements, and therefore, the judgment result indicates that the switch tube Q1 is normal, otherwise, when the switch state signal does not correspond to the drive signal, it is considered that the switch state of the switch tube Q1 is inconsistent with the current circuit requirements, and therefore, the judgment result indicates that the switch tube Q1 is abnormal.

[0056] After obtaining the judgment result, an indication signal corresponding to whether the switch tube is normal or abnormal is obtained, and the indication signal is output; specifically, the specific object of the indication signal output can be set based on actual needs, such as an indication module for reminder, a host computer, or a user device for establishing a communication relationship.

[0057] In this embodiment, a switch state detection module 110 is provided to detect the specific switch condition of the switch tube Q1, so that the processing module 120 can compare the drive signal output by the control chip 210 with the switch state of the switch tube Q1, thereby determining whether a switch abnormality occurs, and indicating based on the specific judgment result, so that the user can determine the switch state based on the indication, and when an abnormality occurs, the abnormality can be checked as soon as possible.

[0058] Further, the switch state detection module 110 includes a current sampling unit 111 and a switch state determination unit 112; the detection end of the current sampling unit 111 is connected to the branch connected to the switch tube Q1, the output end of the current sampling unit 111 is connected to the input end of the switch state determination unit 112, and the output end of the switch state determination unit 112 serves as the output end of the switch state detection module 110; wherein:

[0059] The current sampling unit 111 is used to detect the current of the branch connected to the switch tube Q1 to obtain a detection current, and send a detection voltage corresponding to the detection current to the switch state determination unit 112;

[0060] The switch state determination unit 112 is used to determine the switch state of the switch tube Q1 according to the detection voltage to obtain a switch state signal, and send the switch state signal to the processing module 120 .

[0061] It can be understood that when the switch tube Q1 is turned off, the branch connected to the switch tube Q1 cannot form a loop, so there is no current in the branch connected to the switch tube Q1, and when the switch tube Q1 is turned on, the branch connected to the switch tube Q1 can form a loop, so there is current in the branch connected to the switch tube Q1; it can be seen that the conduction or shutdown of the switch tube Q1 will affect the existence of current in the connected branch, therefore, in this embodiment, by setting a current sampling unit 111 on the branch connected to the switch tube Q1, the switching state of the switch tube Q1 can be accurately determined by the current on the branch.

[0062] The specific type of the current sampling unit 111 can be set based on actual needs, such as a current sensor, a current transformer, a current detection circuit composed of a resistor, etc. In this embodiment and subsequent embodiments, the current sensor is used as an example for explanation, and other types of current sampling units 111 can be implemented by analogy, which will not be repeated. The current sensor obtains a detection current by detecting the branch current of the switch tube Q1, and outputs a detection voltage corresponding to the detection current to the switch state determination unit 112; the switch state determination unit 112 then determines the switch state of the switch tube Q1 according to the detection voltage, and generates a switch state signal to the processing module 120.

[0063] Further, the switch state determination unit 112 includes a comparator B1 and a reference voltage subunit 1121; the non-inverting input terminal of the comparator B1 is connected to the reference voltage subunit 1121 as the input terminal of the switch state determination unit 112, the inverting input terminal of the comparator B1 is connected to the reference voltage subunit 1121, and the output terminal of the comparator B1 is used as the output terminal of the switch state determination unit 112; wherein:

[0064] The reference voltage subunit 1121 is used to provide a reference voltage, wherein when there is no current in the branch connected to the switch tube Q1, the detection voltage output by the current sampling unit 111 is the same as the reference voltage, and when there is current in the branch connected to the switch tube Q1, the detection voltage output by the current sampling unit 111 is greater than the reference voltage;

[0065] The comparator B1 is used to compare the reference voltage with the detection voltage, and when the reference voltage is greater than or equal to the detection voltage, output a switch state signal indicating shutdown to the processing module 120, and when the reference voltage is less than the detection voltage, output a switch state signal indicating conduction to the processing module 120.

[0066] The comparator B1 is used to compare the reference voltage with the detection voltage output by the current sampling unit 111. It can be understood that in order to distinguish the on and off states of the switch tube Q1, the comparator B1 needs to output different signals in different switching states of the switch tube Q1. From the above description, it can be seen that the detection voltage output by the current sampling unit 111 varies with the current of the branch connected to the switch tube Q1. Generally, see Figure 3, there is a positive correlation between the detection voltage output by the current sampling unit 111 and the detection current, that is, the larger the detection current, the larger the corresponding output detection voltage; when the switch tube Q1 is turned off, the detection current is 0, and after the switch tube Q1 is turned on, the detection current gradually increases until it reaches the on-current of the switch tube Q1. Therefore, when the detection current is ≤0, it is considered that the switch tube Q1 is turned off, and when the detection current is greater than 0, it is considered that the switch tube Q1 is turned on; and the detection current corresponds to the detection voltage, therefore, the comparator B1 needs to output a switch state signal indicating that the switch tube Q1 is turned off when the detection voltage is ≤0 for the detection current, and output a switch state signal indicating that the switch tube Q1 is turned on when the detection voltage is greater than 0 for the detection current; and the comparator B1 uses the reference voltage as the judgment basis, therefore, in this embodiment, when there is no current in the branch connected to the switch tube Q1, the current sampling unit The detection voltage output by the current sampling unit 111 is the same as the reference voltage. When there is current in the branch connected to the switch tube Q1, the detection voltage output by the current sampling unit 111 is greater than the reference voltage. At this time, if the switch tube Q1 is turned off and there is no current in the branch connected to the switch tube Q1, the detection voltage output by the current sampling unit 111 is minimum. At the same time, the voltages input to the two-phase input terminals of the comparator B1 are the same. Therefore, the comparator B1 outputs a low-level 0V switch state signal, that is, when the switch state signal is at a low level, it indicates that the switch tube Q1 is turned off; if the switch tube Q1 is turned on, the current in the branch connected to the switch tube Q1 gradually increases, then the detection voltage output by the current unit gradually increases, the voltage at the non-inverting input terminal of the comparator B1 is greater than the voltage at the inverting input terminal, and the comparator B1 outputs a high-level 3.3V switch state signal, that is, when the switch state signal is at a high level, it indicates that the switch tube Q1 is turned on.

[0067] The specific value of the reference voltage is determined based on the parameters of the current sensor. For example, when the current sensor detects a current of 0A, it outputs a detection voltage of 2.5V. As the detection current increases, the detection voltage also increases. At this time, the reference voltage can be set to 2.5V.

[0068] In this embodiment, by setting the comparator B1 and the reference voltage subunit 1121, the specific switching state of the switch tube Q1 can be accurately determined based on the reference voltage that is the same as the detection voltage output by the current sampling unit 111 and the absence of current in the branch connected to the switch tube Q1.

[0069] Furthermore, the switch tube state detection circuit further includes an indication module 130, and the indication module 130 includes a first resistor R1 and a light emitting diode LED, wherein:

[0070] The positive electrode of the light emitting diode LED is connected to the output end of the processing module 120 through the first resistor R1, and the negative electrode of the light emitting diode LED is grounded.

[0071] In this embodiment, the indication module 130 is set to indicate the state of the switch tube Q1; after the processing module 120 obtains the judgment result, the indication state of the indication module 130 is set according to the judgment result; it can be understood that the indication state corresponding to the indication module 130 is different when the switch tube Q1 is normal and when the switch tube Q1 is abnormal; therefore, after obtaining the judgment result, the processing module 120 matches the corresponding indication state based on the specific normal switch tube Q1 and abnormal switch tube Q1, and sends the corresponding indication signal to the indication module 130, so that the indication module 130 adjusts the indication state to be consistent with the judgment result; the specific type of the indication module 130 can be set based on actual needs, including but not limited to sound indication, light indication, and signal sending indication.

[0072] In this embodiment, the state of the switch tube Q1 is indicated specifically by emitting light from the light emitting diode LED.

[0073] When the processing module 120 outputs a high-level indication signal, the indication signal is transmitted to the positive electrode of the light-emitting diode LED through the first resistor R1. The positive electrode of the light-emitting diode LED is at a high level, and the negative electrode is grounded. The voltage across the two ends of the light-emitting diode LED meets the conduction voltage. At this time, the light-emitting diode LED is turned on and lights up.

[0074] When the processing module 120 outputs a low-level indication signal, the indication signal is transmitted to the positive electrode of the light-emitting diode LED through the first resistor R1. The positive electrode of the light-emitting diode LED is at a low level, and the negative electrode is grounded. The voltage across the two ends of the light-emitting diode LED does not meet the conduction voltage. At this time, the light-emitting diode LED is cut off and does not light up.

[0075] It should be noted that, in actual applications, the light emitting diode LED can be turned on to indicate that the switch tube Q1 is normal, and the light emitting diode LED can be turned off to indicate that the switch tube Q1 is abnormal; the light emitting diode LED can also be turned off to indicate that the switch tube Q1 is normal, and the light emitting diode LED can be turned on to indicate that the switch tube Q1 is abnormal; the light emitting diode LED can also be turned on to indicate that the switch tube Q1 is normal, and the light emitting diode LED can be flashed to indicate that the switch tube Q1 is abnormal; the specific correspondence between the light emitting state of the light emitting diode LED and the normal and abnormal states of the switch tube Q1 can be set based on actual needs.

[0076] In this embodiment, a light emitting diode LED is provided so that whether the switch tube Q1 is normal or not can be visually indicated by light.

[0077] The present invention also protects a step-down circuit, which includes a switch tube Q1, a control chip 210, and a switch tube state detection circuit. The structure of the switch tube state detection circuit can refer to the above embodiment and will not be repeated here. As a matter of course, since the step-down circuit of this embodiment adopts the technical solution of the above switch tube state detection circuit, the step-down circuit has all the beneficial effects of the above switch tube state detection circuit.

[0078] Furthermore, the step-down circuit further includes a first inductor L1, a first capacitor C1 and a first diode D1, wherein:

[0079] The input end of the switch tube Q1 is connected to the power supply, the output end of the switch tube Q1 is connected to the first end of the first inductor L1, the first end of the first inductor L1 is also connected to the cathode of the first diode D1, the anode of the first diode D1 is grounded, the second end of the first inductor L1 serves as the output end of the step-down circuit, and the second end of the first inductor L1 is also grounded through the first capacitor C1.

[0080] This embodiment shows a basic BUCK circuit structure, and the specific principles and settings are not described in detail here.

[0081] The present invention provides a switch tube state detection method, referring to Figure 1 , Figure 1 This is a flow chart of a first embodiment of a method for detecting a state of a switch tube according to the present invention. The method for detecting a state of a switch tube is applied to a processing module in the above-mentioned circuit for detecting a state of a switch tube. The method comprises the following steps:

[0082] Step S10, acquiring a switch state signal sent by a switch state detection module and a drive signal sent by a control chip to a switch tube, wherein the switch state signal is obtained by detecting the switch state of the switch tube by the switch state detection module, and the switch tube is switched by the drive signal output by the control chip;

[0083] Step S20, determining whether the switch state signal corresponds to the drive signal, and obtaining a determination result;

[0084] The processing module respectively obtains the switch state signal sent by the switch state detection module and the PWM signal sent by the control chip; it can be understood that the switch state signal indicates the actual switch state of the switch tube, and the PWM signal indicates the expected switch state of the switch tube. Therefore, by comparing the switch state signal with the PWM signal, it can be determined whether the switch state of the switch tube matches the PWM signal output by the control chip, that is, whether the switch state signal corresponds to the drive signal; when the switch state signal corresponds to the drive signal, it is considered that the switch state of the switch tube is consistent with the current circuit requirements, and therefore, the judgment result indicates that the switch tube is normal, conversely, when the switch state signal does not correspond to the drive signal, it is considered that the switch state of the switch tube is inconsistent with the current circuit requirements, and therefore, the judgment result indicates that the switch tube is abnormal.

[0085] Step S30: output an indication signal corresponding to the judgment result.

[0086] After obtaining the judgment result, the processing module sets the indication state of the indication module according to the judgment result; it can be understood that the corresponding indication state of the indication module is different when the switch tube is normal and when the switch tube is abnormal; therefore, after obtaining the judgment result, the processing module matches the corresponding indication state based on the specific normal switch tube and abnormal switch tube, and sends the corresponding indication signal to the indication module, so that the indication module adjusts the indication state to be consistent with the judgment result; the specific type of the indication module can be set based on actual needs, including but not limited to sound indication, light indication, and signal sending indication.

[0087] This embodiment detects the specific switching condition of the switch tube by setting a switch status detection module, so that the processing module can compare the drive signal output by the control chip with the switch status of the switch tube, thereby determining whether a switch abnormality occurs, and indicating based on the specific judgment result, so that the user can determine the switch status based on the indication, and when an abnormality occurs, the abnormality can be checked as soon as possible.

[0088] Furthermore, the step S20 includes:

[0089] Step S21, determining a switch state waveform corresponding to the switch state signal and a drive signal waveform corresponding to the drive signal;

[0090] Step S22, for each driving cycle, determining a first duty cycle of the switch state waveform in the driving cycle, and a second duty cycle of the drive signal waveform in the driving cycle;

[0091] Step S23, determining whether the first duty cycle is consistent with the second duty cycle;

[0092] Step S24, if the first duty cycle is consistent with the second duty cycle, determining that the judgment result is that the switch tube is normal;

[0093] Step S25: if the first duty cycle is inconsistent with the second duty cycle, determining that the judgment result is that the switch tube is abnormal.

[0094] See also Figure 5 The switch state signal is a square wave signal. When the switch tube is turned on, the corresponding switch state signal is a high level. When the switch tube is turned off, the corresponding switch state signal is a low level.

[0095] The PWM signal is also a square wave signal. When the PWM signal is at a high level, the NMOS tube is driven to turn on. When the PWM signal is at a low level, the NMOS tube is driven to turn off.

[0096] Therefore, when the switch tube is normal, the high and low level states of the PWM signal and the corresponding switch state signal should be consistent; therefore, in this embodiment, for each drive cycle, the PWM signal is compared with the switch state signal. The duty cycle is the ratio of the high level in the signal to the entire drive cycle within the drive cycle; the higher the duty cycle, the longer the on time of the switch tube; therefore, by comparing the duty cycle of the PWM signal and the switch state signal, it can be determined whether the on time indicated by the PWM signal is consistent with the actual on time of the switch tube. If they are consistent, the switch tube can be considered normal, and if they are inconsistent, the switch tube is considered abnormal.

[0097] Specifically, the first duty cycle of the switch state signal can be processed by a timer; for example, when the input end of the processing module detects a high level, the timer starts to count, and a number is counted once when the high level is converted to a low level, and a number is counted once when the low level is converted to a high level. The time of the driving cycle and the first duty cycle of the switch state signal are determined by these two numbers.

[0098] In this embodiment, by comparing the duty cycle of the PWM signal with the switch state signal, it is possible to accurately determine whether the PWM signal matches the actual switch state of the switch tube.

[0099] Furthermore, the step S30 includes the steps of:

[0100] Step S31, determining whether the judgment result is that the switch tube is normal or abnormal;

[0101] Step S32, if the judgment result is that the switch tube is abnormal, a high-level indication signal is sent to the indication module to light up the light-emitting diode in the indication module;

[0102] Step S33: If the judgment result is that the switch tube is normal, a low-level indication signal is sent to the indication module to make the light-emitting diode in the indication module not light up.

[0103] When the processing module outputs a high-level indication signal, the indication signal is transmitted to the positive electrode of the light-emitting diode through the first resistor. The positive electrode of the light-emitting diode is at a high level, and the negative electrode is grounded. The voltage across the two ends of the light-emitting diode meets the conduction voltage. At this time, the light-emitting diode is turned on;

[0104] When the processing module outputs a low-level signal, the indication signal is transmitted to the positive electrode of the light-emitting diode through the first resistor. The positive electrode of the light-emitting diode is at a low level, and the negative electrode is grounded. The voltage at both ends of the light-emitting diode does not meet the conduction voltage. At this time, the light-emitting diode is cut off and does not light up.

[0105] It should be noted that in actual applications, the LED can be turned on to indicate that the switch tube is normal, and the LED can be turned off to indicate that the switch tube is abnormal; the LED can also be turned off to indicate that the switch tube is normal, and the LED can be turned on to indicate that the switch tube is abnormal; the LED can also be turned on to indicate that the switch tube is normal, and the LED can be flashed to indicate that the switch tube is abnormal; the specific correspondence between the light-emitting state of the LED and the normal and abnormal states of the switch tube can be set based on actual needs.

[0106] In this embodiment, a light emitting diode is provided so that whether the switch tube is normal or not can be visually indicated by light.

[0107] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0108] Through the description of the above implementation methods, those skilled in the art can clearly understand that the method according to the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a number of instructions for a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in each embodiment of the present application.

[0109] The present application also provides a processing module for implementing the above-mentioned switch tube state detection method, and the processing module includes:

[0110] A first acquisition module is used to acquire a switch state signal sent by a switch state detection module and a drive signal sent by a control chip to a switch tube, wherein the switch state signal is obtained by the switch state detection module detecting the switch state of the switch tube, and the switch tube is switched by the drive signal output by the control chip;

[0111] A first judgment module, used to judge whether the switch state signal corresponds to the drive signal, and obtain a judgment result;

[0112] The first sending module is used to output an indication signal corresponding to the judgment result, so that the indication module indicates the operating state of the switch tube according to the indication signal.

[0113] This processing module detects the specific switching conditions of the switch tube by setting up a switch status detection module, so that the processing module can compare the drive signal output by the control chip with the switch status of the switch tube to determine whether a switch abnormality occurs, and indicate based on the specific judgment result, so that the user can determine the switch status based on the indication, and when an abnormality occurs, the abnormality can be checked as soon as possible.

[0114] It should be noted that the first acquisition module in this embodiment can be used to execute step S10 in the embodiment of the present application, the first judgment module in this embodiment can be used to execute step S20 in the embodiment of the present application, and the first sending module in this embodiment can be used to execute step S30 in the embodiment of the present application.

[0115] Furthermore, the first determination module includes:

[0116] A first determining unit, used to determine a switch state waveform corresponding to the switch state signal and a drive signal waveform corresponding to the drive signal;

[0117] A second determining unit, configured to determine, for each driving cycle, a first duty cycle of the switch state waveform in the driving cycle and a second duty cycle of the drive signal waveform in the driving cycle;

[0118] A first judging unit, configured to judge whether the first duty cycle is consistent with the second duty cycle;

[0119] a third determining unit, configured to determine that the judgment result is that the switch tube is normal if the first duty cycle is consistent with the second duty cycle;

[0120] The fourth determining unit is used to determine that the judgment result is that the switch tube is abnormal if the first duty cycle is inconsistent with the second duty cycle.

[0121] Furthermore, the first sending module includes:

[0122] A fifth determining unit, configured to determine whether the judgment result is that the switch tube is normal or abnormal;

[0123] A first sending unit, configured to send a high-level indication signal to the indication module if the judgment result is that the switch tube is abnormal, so as to light up the light-emitting diode in the indication module;

[0124] The second sending unit is used to send a low-level indication signal to the indication module if the judgment result is that the switch tube is normal, so that the light-emitting diode in the indication module is not lit.

[0125] Reference Figure 6 In terms of hardware structure, the processing module may include components such as a communication module 10, a memory 20, and a processor 30. In the processing module, the processor 30 is connected to the memory 20 and the communication module 10 respectively, and a computer program is stored in the memory 20. The computer program is executed by the processor 30 at the same time, and the steps of the above method embodiment are implemented when the computer program is executed.

[0126] The communication module 10 can be connected to an external communication device through a network. The communication module 10 can receive requests from an external communication device, and can also send requests, instructions and information to the external communication device, which can be other processing modules, servers or Internet of Things devices, such as televisions, etc.

[0127] The memory 20 can be used to store software programs and various data. The memory 20 can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application required for a function (such as obtaining a switch state signal sent by a switch state detection module), etc.; the data storage area can include a database, and the data storage area can store data or information created according to the use of the system, etc. In addition, the memory 20 can include a high-speed random access memory, and can also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0128] The processor 30 is the control center of the processing module. It uses various interfaces and lines to connect various parts of the entire processing module. It executes various functions of the processing module and processes data by running or executing software programs and / or modules stored in the memory 20, and calling data stored in the memory 20, so as to monitor the processing module as a whole. The processor 30 may include one or more processing units; optionally, the processor 30 may integrate an application processor and a modem processor, wherein the application processor mainly processes the operating system, user interface, and application programs, and the modem processor mainly processes wireless communications. It is understandable that the above-mentioned modem processor may not be integrated into the processor 30.

[0129] although Figure 6 Although not shown, the processing module may further include a circuit control module, which is used to connect to a power source to ensure the normal operation of other components. Figure 6 The processing module structure shown in the figure does not constitute a limitation on the processing module, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0130] The present invention also provides an electronic device on which a computer program is stored. The electronic device may be Figure 6 The memory 20 in the electronic device may also be at least one of a ROM (Read-Only Memory) / RAM (Random Access Memory), a magnetic disk, and an optical disk. The electronic device includes a plurality of instructions for enabling a terminal device with a processor (which may be a television, a car, a mobile phone, a computer, a server, a terminal, or a network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0131] In the present invention, the terms "first", "second", "third", "fourth" and "fifth" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0132] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0133] Although the embodiments of the present invention have been shown and described above, the scope of protection of the present invention is not limited thereto. It is understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. A person of ordinary skill in the art can change, modify and replace the above embodiments within the scope of the present invention, and these changes, modifications and replacements should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A switch tube state detection circuit, characterized in that: The switch tube state detection circuit is connected to the switch tube and the control chip respectively, and the switch tube is switched by the driving signal output by the control chip; the switch tube state detection circuit includes a switch state detection module and a processing module; The detection end of the switch state detection module is connected to the branch connected to the switch tube, the output end of the switch state detection module is connected to the first input end of the processing module, and the second input end of the processing module is connected to the control chip; wherein: The switch state detection module is used to detect the switch state of the switch tube to obtain a switch state signal, and send the switch state signal to the processing module; The processing module is used to obtain the switch state signal sent by the switch state detection module and the drive signal sent by the control chip to the switch tube, and to determine whether the switch state signal corresponds to the drive signal, obtain a determination result, and output an indication signal corresponding to the determination result.

2. The switch tube state detection circuit according to claim 1, characterized in that: The switch state detection module includes a current sampling unit and a switch state determination unit; the detection end of the current sampling unit is connected to the branch connected to the switch tube, the output end of the current sampling unit is connected to the input end of the switch state determination unit, and the output end of the switch state determination unit serves as the output end of the switch state detection module; wherein: The current sampling unit is used to detect the current of the branch connected to the switch tube to obtain a detection current, and send a detection voltage corresponding to the detection current to the switch state determination unit; The switch state determination unit is used to determine the switch state of the switch tube according to the detection voltage to obtain a switch state signal, and send the switch state signal to the processing module.

3. The switch tube state detection circuit according to claim 2, characterized in that: The switch state determination unit includes a comparator and a reference voltage subunit; the non-inverting input terminal of the comparator is used as the input terminal of the switch state determination unit, the inverting input terminal of the comparator is connected to the reference voltage subunit, and the output terminal of the comparator is used as the output terminal of the switch state determination unit; wherein: The reference voltage subunit is used to provide a reference voltage, wherein when there is no current in the branch connected to the switch tube, the detection voltage output by the current sampling unit is the same as the reference voltage, and when there is current in the branch connected to the switch tube, the detection voltage output by the current sampling unit is greater than the reference voltage; The comparator is used to compare the reference voltage with the detection voltage, and when the reference voltage is greater than or equal to the detection voltage, output a switch state signal indicating shutdown to the processing module, and when the reference voltage is less than the detection voltage, output a switch state signal indicating conduction to the processing module.

4. The switch tube state detection circuit according to claim 1, characterized in that: The switch tube state detection circuit further includes an indication module, which includes a first resistor and a light emitting diode, wherein: The positive electrode of the light emitting diode is connected to the output end of the processing module through the first resistor, and the negative electrode of the light emitting diode is grounded.

5. A step-down circuit, characterized in that: The step-down circuit comprises a switch tube, a control chip and a switch tube state detection circuit according to any one of claims 1 to 4.

6. The step-down circuit according to claim 5, characterized in that: The step-down circuit further includes a first inductor, a first capacitor and a first diode, wherein: The input end of the switch tube is connected to the power supply, the output end of the switch tube is connected to the first end of the first inductor, the first end of the first inductor is also connected to the cathode of the first diode, the anode of the first diode is grounded, the second end of the first inductor serves as the output end of the step-down circuit, and the second end of the first inductor is also grounded through the first capacitor.

7. A method for detecting a switch tube state, characterized in that: The switch tube state detection method is applied to a processing module in a switch tube state detection circuit according to any one of claims 1 to 4; The switch tube state detection method comprises: Acquire a switch state signal sent by a switch state detection module and a drive signal sent by a control chip to a switch tube, wherein the switch state signal is obtained by detecting the switch state of the switch tube by the switch state detection module, and the switch tube is switched by the drive signal output by the control chip; Determine whether the switch state signal corresponds to the drive signal, and obtain a determination result; An indication signal corresponding to the judgment result is output.

8. The switch tube state detection method according to claim 7, characterized in that: The determining whether the switch state signal corresponds to the drive signal and obtaining a determination result includes: Determine a switch state waveform corresponding to the switch state signal and a drive signal waveform corresponding to the drive signal; For each driving cycle, determining a first duty cycle of the switch state waveform in the driving cycle and a second duty cycle of the drive signal waveform in the driving cycle; Determining whether the first duty cycle is consistent with the second duty cycle; If the first duty cycle is consistent with the second duty cycle, determining that the judgment result is that the switch tube is normal; If the first duty cycle is inconsistent with the second duty cycle, it is determined that the judgment result is that the switch tube is abnormal.

9. The switch tube state detection method according to claim 7, characterized in that: The outputting of the indication signal corresponding to the judgment result comprises: Determining that the judgment result is that the switch tube is normal or the switch tube is abnormal; If the judgment result is that the switch tube is abnormal, a high-level indication signal is sent to the indication module to light up the light-emitting diode in the indication module; If the judgment result is that the switch tube is normal, a low-level indication signal is sent to the indication module so that the light-emitting diode in the indication module does not light up.

10. An electronic device, characterized in that: The electronic device stores a computer program, and when the computer program is executed by a processor, the steps of the switch tube state detection method according to any one of claims 7 to 9 are implemented.

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