Detection circuit and electronic device

Abstract

This application provides a detection circuit and electronic device. The detection circuit includes: a voltage divider module with a first terminal coupled to a voltage source and a second terminal coupled to a device under test (DUT); a first switch module with a control terminal coupled to a second terminal of the voltage divider module, a first terminal coupled to a third terminal of the voltage divider module, and the second terminal grounded; a second switch module with a control terminal coupled to the third terminal of the voltage divider module, a first terminal coupled to a voltage source, and a second terminal grounded; and a first terminal of the second switch module serving as the output terminal of the detection circuit, used to output a detection signal. The detection signal characterizes different states of the DUT. Through the above method, using the switches and voltage divider module, corresponding detection signals are output according to different resistance values ​​connected to the DUT, and the connection state of the DUT or the ambient temperature is determined based on the detection signals.

Description

Technical Field

[0001] This application relates primarily to the field of electronic circuit technology, and in particular to detection circuits and electronic equipment. Background Technology

[0002] In traditional device testing, headphone insertion detection works by using a voltage divider to control a transistor's switching, thus outputting high and low voltage levels based on the microphone's impedance to ground. However, this method has a problem: the headphone icon can still be displayed even when the headphones are not fully inserted. This is because the circuit can only distinguish between two input types and cannot differentiate between headphones that are inserted and those that are not. In other words, it cannot correctly identify the device's connection status. Therefore, voltage differentiation is needed to determine the input status. Similarly, in some temperature detection processes, voltage differentiation is required to determine the ambient temperature. Common solutions use voltage sampling or window comparators to differentiate voltages, but these solutions involve complex circuit structures and components, leading to significant costs and excessive resource consumption. Utility Model Content

[0003] The main purpose of this application is to provide detection circuits and electronic equipment to solve the problem of detecting different access states or ambient temperatures of the device under test, so as to realize voltage detection in different areas using simple circuits and output detection signals for judgment.

[0004] To address the aforementioned problems, this application provides a detection circuit and an electronic device. The detection circuit includes: a voltage divider module, with a first terminal coupled to a voltage source and a second terminal coupled to a device under test; a first switch module, with a control terminal coupled to a second terminal of the voltage divider module, a first terminal coupled to a third terminal of the voltage divider module, and the second terminal grounded; and a second switch module, with a control terminal coupled to the third terminal of the voltage divider module, a first terminal coupled to a voltage source, and the second terminal grounded. The first terminal of the second switch module is the output terminal of the detection circuit, used to output a detection signal, which characterizes different states of the device under test.

[0005] In one embodiment, the voltage divider module includes: a first resistor, a first end of which is coupled to a voltage source, and a second end of which is coupled to a control terminal of a first switching module; and a second resistor, a first end of which is coupled to a second end of the first resistor, and a second end of which is coupled to a control terminal of a second switching module.

[0006] In one embodiment, the first switching module includes: a first voltage divider unit, a first terminal of which is coupled to a second terminal of the voltage divider module, and the second terminal of which is grounded; a second voltage divider unit, a first terminal of which is coupled to a third terminal of the voltage divider module; and a first switching unit, a control terminal of which is coupled to the third terminal of the first voltage divider unit, a first terminal of which is grounded, and a second terminal of which is coupled to the second terminal of the second voltage divider unit.

[0007] In one embodiment, the first voltage divider unit includes: a third resistor, the first end of which is coupled to the second end of the voltage divider module, and the second end of which is coupled to the control terminal of the first switching unit; and a fourth resistor, the first end of which is coupled to the second end of the third resistor, and the second end of which is grounded.

[0008] In one embodiment, the second voltage divider unit includes a fifth resistor, the first end of which is coupled to the third end of the voltage divider module, and the second end of which is coupled to the second end of the first switching unit.

[0009] In one embodiment, the second switching module includes: a third voltage divider unit, the first end of which is coupled to the third end of the voltage divider module, and the second end of which is grounded; a fourth voltage divider unit, the first end of which is coupled to a voltage source, and the second end of which is the output terminal of a detection circuit for outputting a detection signal; and a second switching unit, the control terminal of which is coupled to the third end of the voltage divider module, the first end of which is grounded, and the second end of which is coupled to the third end of the fourth voltage divider unit.

[0010] In one embodiment, the third voltage divider unit includes a sixth resistor, the first end of which is coupled to the third end of the voltage divider module, and the second end of which is grounded.

[0011] In one embodiment, the fourth voltage divider unit includes: a seventh resistor, the first end of which is coupled to a voltage source, and the second end of which is coupled to the second end of a second switching unit; and an eighth resistor, the first end of which is coupled to the second end of the seventh resistor, and the second end of which is the output terminal of the detection circuit for outputting a detection signal.

[0012] In one embodiment, the device under test is a temperature sensing resistor.

[0013] To address the aforementioned problems, this application also provides an electronic device comprising: a power supply and a detection circuit; the detection circuit is coupled to the power supply and is the detection circuit described in any of the above embodiments.

[0014] This application provides a detection circuit and electronic equipment. Based on a voltage divider module, the first and / or second switch modules are controlled to switch on and off according to the different impedances of the device under test (DUT) and output a detection signal to determine the connection status of the DUT or the ambient temperature of the DUT based on the detection signal. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0016] Figure 1 This is a schematic diagram of the structure of the first embodiment of the detection circuit provided in this application;

[0017] Figure 2 This is a schematic diagram of the structure of an embodiment of the voltage divider module provided in this application;

[0018] Figure 3 This is a schematic diagram of the structure of an embodiment of the first switch module provided in this application;

[0019] Figure 4 This is a schematic diagram of the structure of an embodiment of the first voltage divider unit provided in this application;

[0020] Figure 5 This is a schematic diagram of the structure of an embodiment of the second voltage divider unit provided in this application;

[0021] Figure 6 This is a schematic diagram of the structure of an embodiment of the second switch module provided in this application;

[0022] Figure 7 This is a schematic diagram of the structure of an embodiment of the third voltage divider unit provided in this application;

[0023] Figure 8 This is a schematic diagram of the structure of an embodiment of the fourth voltage divider unit provided in this application;

[0024] Figure 9 This is a schematic diagram of the second embodiment of the detection circuit provided in this application;

[0025] Figure 10 This is a schematic diagram of the structure of an embodiment of the electronic device provided in this application.

[0026] Icon labels:

[0027] 100. Detection circuit; 10. Voltage divider module; 20. First switch module; 21. First voltage divider unit; 22. Second voltage divider unit; 23. First switch unit; 30. Second switch module; 31. Third voltage divider unit; 32. Fourth voltage divider unit; 33. Second switch unit; 40. Device under test; 200. Electronic equipment; 210. Power supply. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It is understood that the specific embodiments described herein are only for explaining this application and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings, not all structures. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0029] The terms "first," "second," etc., used in this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0030] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0031] Based on how to detect different access states of devices, traditional solutions typically use an ADC (Analog-to-Digital Converter) or a window comparator to sample the impedance of the device and output a corresponding level signal. The ADC sampler samples the impedance of the external input device, converts it into a digital signal, and compares it with a set value to determine the type of device accessed. The window comparator usually consists of two comparators (a dual comparator with two threshold voltages VTHH (high threshold voltage) and VTHL (low threshold voltage), and the voltage VA compared with VTHH and VTHL is input to both comparators. If VTHL ≤ VA ≤ VTHH, Vout outputs a high level; if VA ≤ VTHH, the output is high.<VTHL,VA> If VTHH is set, then Vout will output a low level, which is mainly used to detect whether the input signal is within the set threshold range and to provide feedback based on the output level signal.

[0032] In most cases, ADC sampling schemes are embedded in the platform chip. To use them independently, an additional ADC chip is required, significantly increasing project costs and making them susceptible to interference if not properly shielded. Window comparators, on the other hand, are complex to build, expensive, and occupy space, further increasing circuit costs. Therefore, this application provides a detection circuit and electronic device to solve the above problems.

[0033] See Figure 1 As shown, Figure 1 This is a schematic diagram of the structure of the first embodiment of the detection circuit provided in this application; the detection circuit 100 includes: a voltage divider module 10, a first switch module 20, and a second switch module 30; specifically, the first terminal of the voltage divider module 10 is coupled to a voltage source, and the second terminal of the voltage divider module 10 is used to couple to the device under test 40; the control terminal of the first switch module 20 is coupled to the second terminal of the voltage divider module 10, the first terminal of the first switch module 20 is coupled to the third terminal of the voltage divider module 10, and the second terminal of the first switch module 20 is grounded; the control terminal of the second switch module 30 is coupled to the third terminal of the voltage divider module 10, the first terminal of the second switch module 30 is coupled to a voltage source, the second terminal of the second switch module 30 is grounded, and the first terminal of the second switch module 30 is the output terminal of the detection circuit 100, used to output a detection signal, which is used to characterize different states of the device under test 40.

[0034] The state of the device under test 40 can be an access state, which includes: not accessed, short circuit / open circuit, and accessed in place; or the state of the device under test can be the ambient temperature, and the detection signal is used to characterize the ambient temperature of the device under test 40. This is only an example for illustration. Other states of the device under test are also within the protection scope of this application, and will not be described in detail here.

[0035] In the above embodiments, a detection circuit 100 is constructed using only a switching module and a voltage divider module 10, which efficiently and simply detects different circuit voltages to detect the device connection status or ambient temperature, saving costs and improving efficiency.

[0036] Understandably, a detection circuit 100 is constructed using a first switch module 20 and a second switch module 30 combined with a voltage divider module 10. Each of the first switch module 20 and the second switch module 30 has its own on-state voltage. When the voltage signal detected at the control terminal is greater than the on-state voltage, the first switch module 20 and / or the second switch module 30 are turned on; when the voltage signal detected at the control terminal is less than the on-state voltage, the first switch module 20 and / or the second switch module 30 are turned off. By controlling the on / off state of the first switch module 20 and / or the second switch module 30, and in conjunction with the voltage divider module 10, the output level is switched, and the connection status of the device under test 40 is determined based on the output detection signal.

[0037] Among them, the determination of the status of not connected, short circuit / open circuit, and connected can be based on the output detection signal and the continuity of the equipment detection process to determine the specific status of the device under test 40.

[0038] In one embodiment, the device under test 40 is a temperature sensing resistor.

[0039] It is understood that, based on the above embodiments, in some other embodiments, the device under test 40 can be a temperature sensing resistor. A temperature sensing resistor, also known as a thermistor, is a component that measures temperature by utilizing the characteristic that its resistance changes with temperature. Its working principle is based on the property that the resistance of a material changes with temperature; by measuring the change in resistance, the current temperature is calculated. Since the resistance of the temperature sensing resistor changes with temperature, the corresponding output detection signal will also change due to the change in the resistance of the temperature sensing resistor, and thus the ambient temperature can be measured and determined through the output detection signal.

[0040] In some embodiments, the temperature sensing resistor may include, but is not limited to, NTC thermistors (negative temperature coefficient) and PTC thermistors (positive temperature coefficient). The resistance of an NTC thermistor decreases as temperature increases, while the resistance of a PTC thermistor increases as temperature increases. Different temperature sensing resistors are selected based on different practical situations to meet the requirements of ambient temperature detection; no specific limitations are imposed here.

[0041] In one embodiment, such as Figure 2 As shown, Figure 2This is a schematic diagram of a voltage divider module according to an embodiment of the present application; wherein, the voltage divider module 10 includes: a first resistor R1 and a second resistor R2; the first end of the first resistor R1 is coupled to a voltage source, and the second end of the first resistor R1 is coupled to the control terminal of the first switch module 20; the first end of the second resistor R2 is coupled to the second end of the first resistor R1, and the second end of the second resistor R2 is coupled to the control terminal of the second switch module 30.

[0042] Understandably, a voltage divider module 10 is installed at the power supply input to reduce and stabilize the voltage, thereby adjusting the output voltage to meet circuit requirements. Specifically, based on the different ports of the first resistor R1 and the second resistor R2, the voltage values ​​of different branches are further adjusted to achieve functions such as adjusting the voltage division ratio and / or logic level conversion.

[0043] In one embodiment, such as Figure 3 As shown, Figure 3 This is a schematic diagram of an embodiment of the first switching module provided in this application; the first switching module 20 includes: a first voltage divider unit 21, a second voltage divider unit 22, and a first switching unit 23; the first end of the first voltage divider unit 21 is coupled to the second end of the voltage divider module 10, and the second end of the first voltage divider unit 21 is grounded. The first end of the second voltage divider unit 22 is coupled to the third end of the voltage divider module 10; the control end of the first switching unit 23 is coupled to the third end of the first voltage divider unit 21, the first end of the first switching unit 23 is grounded, and the second end of the first switching unit 23 is coupled to the second end of the second voltage divider unit 22.

[0044] Specifically, by setting a first voltage divider unit 21 and a second voltage divider unit 22 at different ports of the first switching unit 23, the voltage requirements of different branches can be met accordingly. Furthermore, the voltage can be adjusted according to the first voltage divider unit 21 and / or the second voltage divider unit 22 to correspond to different logic level conversions.

[0045] In one embodiment, the first switching unit 23 can be a P-type MOS transistor or an N-type MOS transistor.

[0046] In one embodiment, such as Figure 4 As shown, Figure 4 This is a schematic diagram of the structure of an embodiment of the first voltage divider unit provided in this application; the first voltage divider unit 21 includes: a third resistor R3 and a fourth resistor R4; wherein, the first end of the third resistor R3 is coupled to the second end of the voltage divider module 10, and the second end of the third resistor R3 is coupled to the control end of the first switching unit 23; the first end of the fourth resistor R4 is coupled to the second end of the third resistor R3, and the second end of the fourth resistor R4 is grounded.

[0047] In one embodiment, such as Figure 5 As shown, Figure 5This is a schematic diagram of an embodiment of the second voltage divider unit provided in this application; the second voltage divider unit 22 includes: a fifth resistor R5, the first end of the fifth resistor R5 is coupled to the third end of the voltage divider module 10, and the second end of the fifth resistor R5 is coupled to the second end of the first switching unit 23.

[0048] Understandably, by adjusting the resistance values ​​of the first voltage divider unit 21 and / or the second voltage divider unit 22, the detection range of the detection circuit 100 can be adjusted to meet the detection requirements of the device under test 40.

[0049] In one embodiment, such as Figure 6 As shown, Figure 6 This is a schematic diagram of an embodiment of the second switching module provided in this application; the second switching module 30 includes: a third voltage divider unit 31, a fourth voltage divider unit 32, and a second switching unit 33; specifically, the first end of the third voltage divider unit 31 is coupled to the third end of the voltage divider module 10, and the second end of the third voltage divider unit 31 is grounded; the first end of the fourth voltage divider unit 32 is coupled to a voltage source, and the second end of the fourth voltage divider unit 32 is the output end of the detection circuit 100, used to output a detection signal; the control end of the second switching unit 33 is coupled to the third end of the voltage divider module 10, the first end of the second switching unit 33 is grounded, and the second end of the second switching unit 33 is coupled to the third end of the fourth voltage divider unit 32.

[0050] In one embodiment, the second switching unit 33 can be a P-type MOS transistor or an N-type MOS transistor.

[0051] In one embodiment, such as Figure 7 As shown, Figure 7 This is a schematic diagram of an embodiment of the third voltage divider unit provided in this application; the third voltage divider unit 31 includes: a sixth resistor R6, the first end of the sixth resistor R6 is coupled to the third end of the voltage divider module 10, and the second end of the sixth resistor R6 is grounded.

[0052] In one embodiment, such as Figure 8 As shown, Figure 8 This is a schematic diagram of an embodiment of the fourth voltage divider unit provided in this application; the fourth voltage divider unit 32 includes: a seventh resistor R7 and an eighth resistor R8; the first end of the seventh resistor R7 is coupled to a voltage source, and the second end of the seventh resistor R7 is coupled to the second end of the second switching unit 33; the first end of the eighth resistor R8 is coupled to the second end of the seventh resistor R7, and the second end of the eighth resistor R8 is the output end of the detection circuit 100, used to output a detection signal.

[0053] Corresponding to the above embodiments and the solution of this application, the impedance values ​​of the device under test 40 in the circuit are different depending on the different access states of the device under test 40.

[0054] When the impedance of the device under test 40 is 0, the voltage divider of the branch of the device under test 40 and the voltage divider module 10 is combined to make the first switch module 20 be turned off and the second switch module 30 be turned on. At this time, the detection signal output by the circuit output terminal is in a high-level state.

[0055] When the impedance of the connected device (device under test 40) increases to a certain level, the load resistance, denoted as RLL, is divided by the load resistance and the peripheral circuit of the partition detection circuit 100, causing the second switch module 30 to conduct and the first switch module 20 to de-conduct. At this time, the detection signal output by the circuit is low. For example, when the impedance of the device is within the range of greater than 1.5KΩ and less than 14KΩ, the detection signal output by the circuit is low. Conversely, for the range of 0-1.5KΩ, the detection signal output by the circuit is high.

[0056] When the impedance of the connected device increases to a high level, the load resistance, denoted as RLH, is divided by the load resistance and the peripheral circuit of the detection circuit 100, causing the first switching module 20 to conduct. Because the gate (control terminal) of the second switching module is connected to the drain of the first switching module 20, the second switching module 30 is not conducted, and the corresponding output state of the circuit is high. For example, when the impedance of the device is greater than 14KΩ, the detection signal output by the circuit is high.

[0057] When the impedance of the connected device continues to increase until it is disconnected, the first switch module 20 remains on. Because the gate (control terminal) of the second switch module 30 is connected to the drain of the first switch module 20, the second switch module 30 is not on, and the corresponding output state is high. For example, when the impedance of the device is greater than 14KΩ and remains there until the device is disconnected and in an unloaded state, the corresponding output state is high.

[0058] It is understandable that the device under test 40 corresponds to different impedances to output different level values. In some other embodiments, the detection range of resistance value detection from 1.5K to 14K is simulated. In this range, the state of the detection signal output by the detection circuit 100 is 0 (i.e., low level state). In other ranges, the state of the output detection signal is 1 (i.e., high level state).

[0059] Furthermore, in other embodiments, the detection range of the circuit can be changed by adjusting the voltage divider parameters. For example, the resistance range detected by the circuit can be changed by adjusting the voltage divider module 10 and / or the voltage divider unit in the above embodiments.

[0060] See Figure 9 As shown, Figure 9This is a schematic diagram of the second embodiment of the detection circuit provided in this application; the first switching unit 23 is an N-type MOS transistor Q1, and the second switching unit 33 is an N-type MOS transistor Q2. In conjunction with the above embodiment, the detection range of the detection circuit 100 can be adjusted by adjusting the resistance parameters between the second resistor R2, the third resistor R3, the fourth resistor R4 and the sixth resistor R6.

[0061] In other embodiments, the detection circuit 100 in the above embodiments can also be used for device screening. It is understood that for multiple devices with the same interface but different impedances, this circuit can be used to screen out devices with impedance values ​​that meet the detection range, thus serving a screening and judgment function.

[0062] To address the aforementioned problems, this application also provides an electronic device 200, such as... Figure 10 As shown, Figure 10 This is a schematic diagram of an embodiment of the electronic device provided in this application; the electronic device 200 includes: a power supply 210 and a detection circuit 100; the detection circuit 100 is coupled to the power supply 210, and the detection circuit 100 is the detection circuit 100 described in any of the above embodiments, wherein the power supply 210 can be used as a voltage source in the aforementioned embodiments, or it can be a separately provided power supply for the electronic device.

[0063] The detection circuit 100 and electronic device 200 provided in this application, through the first switch module 20 and the second switch module 30, combined with the voltage divider module 10, control the on / off state of the first switch module 20 and / or the second switch module 30 according to the different impedances of the connected device under test 40, and output a detection signal to determine the connection status of the device under test 40 or the ambient temperature of the device under test 40. Alternatively, the above method can be used to distinguish between different connected devices under test 40 and to screen the devices under test 40.

[0064] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A detection circuit, characterized in that, The detection circuit includes: A voltage divider module, wherein the first end of the voltage divider module is coupled to a voltage source, and the second end of the voltage divider module is used to couple to the device under test; A first switching module, wherein the control terminal of the first switching module is coupled to the second terminal of the voltage divider module, the first terminal of the first switching module is coupled to the third terminal of the voltage divider module, and the second terminal of the first switching module is grounded; The second switching module has its control terminal coupled to the third terminal of the voltage divider module, its first terminal coupled to a voltage source, its second terminal grounded, and its first terminal serving as the output terminal of the detection circuit for outputting a detection signal. The detection signal is used to characterize different states of the device under test.

2. The detection circuit according to claim 1, characterized in that, The voltage divider module includes: A first resistor, with its first end coupled to the voltage source and its second end coupled to the control terminal of the first switching module; The second resistor has a first end coupled to the second end of the first resistor, and the second end of the second resistor is coupled to the control terminal of the second switch module.

3. The detection circuit according to claim 1, characterized in that, The first switch module includes: A first voltage divider unit, wherein a first end of the first voltage divider unit is coupled to a second end of the voltage divider module, and the second end of the first voltage divider unit is grounded; The second voltage divider unit has a first end coupled to the third end of the voltage divider module; The first switching unit has a control terminal coupled to the third terminal of the first voltage divider unit, a first terminal of the first switching unit grounded, and a second terminal of the first switching unit coupled to the second terminal of the second voltage divider unit.

4. The detection circuit according to claim 3, characterized in that, The first voltage divider unit includes: The third resistor has its first end coupled to the second end of the voltage divider module, and its second end coupled to the control end of the first switching unit. A fourth resistor, the first end of which is coupled to the second end of the third resistor, and the second end of the fourth resistor is grounded.

5. The detection circuit according to claim 3, characterized in that, The second voltage divider unit includes: The fifth resistor has its first end coupled to the third end of the voltage divider module and its second end coupled to the second end of the first switching unit.

6. The detection circuit according to claim 1, characterized in that, The second switch module includes: The third voltage divider unit has a first terminal coupled to the third terminal of the voltage divider module and a second terminal grounded. The fourth voltage divider unit has its first terminal coupled to a voltage source and its second terminal serving as the output terminal of the detection circuit for outputting a detection signal. The second switching unit has its control terminal coupled to the third terminal of the voltage divider module, its first terminal grounded, and its second terminal coupled to the third terminal of the fourth voltage divider unit.

7. The detection circuit according to claim 6, characterized in that, The third voltage divider unit includes: The sixth resistor has its first end coupled to the third end of the voltage divider module and its second end grounded.

8. The detection circuit according to claim 6, characterized in that, The fourth voltage divider unit includes: The seventh resistor has a first terminal coupled to a voltage source and a second terminal coupled to the second terminal of the second switching unit. The eighth resistor has its first end coupled to the second end of the seventh resistor, and the second end of the eighth resistor is the output terminal of the detection circuit, used to output a detection signal.

9. The detection circuit according to claim 1, characterized in that, The device under test is a temperature sensing resistor.

10. An electronic device, characterized in that, The electronic device includes: power supply; A detection circuit, the detection circuit being coupled to the power supply, the detection circuit being the detection circuit as described in any one of claims 1-9.

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