Water vapor detection circuit and electronic device

Abstract

Embodiments of the present application disclose a kind of water vapor detection circuit.Water vapor detection circuit includes signal source circuit, first current source circuit, first CC line, Type-C interface, second current source and voltage comparison circuit.Two groups of current source circuit respectively through first CC line and second CC line, first voltage and second voltage are transmitted to voltage comparison circuit;When first voltage is less than second voltage, voltage comparison circuit outputs first comparison signal, indicating that the water vapor erosion degree of Type-C interface is lower than preset degree;When first voltage is greater than second voltage, voltage comparison circuit outputs second comparison signal, indicating that the water vapor erosion degree of Type-C interface is higher than preset degree.The present application uses as few as possible circuit to realize the water vapor detection of Type-C interface, does not increase external circuit, does not change Type-C interface structure, so that it can be realized in most scenarios, it is advantageous to save cost.

Description

Technical Field

[0001] This application relates to the field of circuit detection, and more particularly to a water vapor detection circuit and electronic device. Background Technology

[0002] In recent years, the Type-C interface has been used in a large number of mobile devices. The wide range of devices using the Type-C interface also means a wide range of usage scenarios and complex environments. Moisture intrusion in various scenarios can eventually lead to short circuits, corrosion, or signal interference in the interface. Therefore, moisture detection has become an urgent need.

[0003] One existing technology proposes adding probes to the interface to determine the presence of moisture intrusion by observing the changes in voltage and current characteristics when the interface becomes wet. However, measuring the voltage and current characteristics of the interface would significantly increase costs and place high demands on the power management chip, making it difficult to implement. Another solution proposes designing a new Type-C interface by embedding a metal plate within the plastic-encapsulated tongue of the female connector to form a capacitor with the ground wire. When moisture intrusion occurs, the capacitance value changes. However, this solution requires a new Type-C interface, which cannot be used in the hundreds of millions of Type-C interfaces produced in the past, and it would also increase costs for the latest devices. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a water vapor detection circuit and electronic device to solve the technical issues of requiring new interfaces and increasing costs in related technologies.

[0005] In a first aspect, embodiments of this application provide a water vapor detection circuit, comprising: The signal source circuit is configured to output a drive voltage. A first current source, electrically connected to the signal source circuit, is configured to output a first voltage in response to the input of the driving voltage; The first CC line is electrically connected to the first current source and is configured to transmit the first voltage; A Type-C interface, including a second CC line, wherein the Type-C interface generates an impedance equivalent circuit when exposed to moisture, and the impedance equivalent circuit is electrically connected to the second CC line; The second current source, electrically connected to the signal source circuit and the second CC line respectively, is configured to transmit a target current through the second CC line in response to the input of the driving voltage. The target current flows through the impedance equivalent circuit to generate a second voltage in the impedance equivalent circuit. A voltage comparison circuit, electrically connected to the first CC line and the second CC line respectively, is configured to receive a first voltage transmitted by the first CC line and a second voltage transmitted by the second CC line respectively, and output a first comparison signal in response to the first voltage being less than the second voltage, or output a second comparison signal in response to the first voltage being greater than the second voltage. The first comparison signal is used to indicate that the moisture erosion level of the Type-C interface is lower than a preset level, and the second comparison signal is used to indicate that the moisture erosion level of the Type-C interface is higher than a preset level.

[0006] Optionally, the first current source of the water vapor detection circuit may also include: The reference voltage output circuit is configured to output a custom target reference voltage; A first voltage processing circuit, electrically connected to the reference voltage output circuit and the signal source circuit respectively, and electrically connected to the voltage comparison circuit through the first CC line, is configured to output the first voltage to the voltage comparison circuit through the first CC line in response to the input of the target reference voltage, wherein the target reference voltage is proportional to the first voltage.

[0007] Preferably, the target reference voltage includes a first reference voltage, and the first voltage processing circuit includes: The delay processing circuit is electrically connected to the reference voltage output circuit and the signal source circuit, respectively, and is configured to output a delay signal in response to the input of the driving voltage and the first reference voltage, wherein the voltage amplitude of the delay signal is inversely proportional to the first reference voltage; A step-down processing circuit, electrically connected to the delay processing circuit, is configured to output a step-down signal in response to the input of the delay signal, wherein the voltage amplitude of the step-down signal is proportional to the voltage amplitude of the delay signal. A first signal driving circuit, electrically connected to the buck processing circuit and also electrically connected to the first CC line, is configured to output the first voltage to the voltage comparison circuit through the first CC line in response to the input of the buck signal, wherein the voltage amplitude of the buck signal is proportional to the first voltage.

[0008] Further specifying, the delay processing circuit includes: An integrating circuit, electrically connected to the reference voltage output circuit and the signal source circuit respectively, is configured to integrate the driving voltage in response to the input driving voltage to obtain an integrated voltage; A first voltage comparator, the positive terminal of which is electrically connected to the integrating circuit, the negative terminal of which is electrically connected to the reference voltage output circuit, and the output terminal of which is electrically connected to the buck processing circuit, is configured to output a high level in response to the integrated voltage being greater than the first reference voltage, or to output a low level in response to the integrated voltage being less than the first reference voltage.

[0009] Preferably, the step-down processing circuit includes: A delay drive circuit, electrically connected to the delay processing circuit, is configured to output a delay drive signal in response to the input of the delay signal; A step-down circuit, electrically connected to the delay drive circuit and the first signal drive circuit respectively, is configured to output a step-down signal in response to the input of the delay signal, wherein the voltage amplitude of the step-down signal is proportional to the voltage amplitude of the delay signal; A feedback drive circuit, electrically connected to the buck circuit, is configured to sample the buck signal output by the buck circuit and control the operating state of the buck circuit based on the buck signal.

[0010] Further specifying, the target reference voltage includes a second reference voltage, and the feedback drive circuit includes: A sampling circuit, electrically connected to the step-down circuit, is configured to sample the step-down signal output by the step-down circuit to obtain a sampling voltage; A buck comparator circuit, electrically connected to the sampling circuit, is configured to output a comparison voltage in response to inputs of the sampling voltage and the second reference voltage; The pulse generation circuit is electrically connected to the buck comparator circuit and the buck circuit respectively, and is configured to output a pulse drive signal based on the comparison voltage and the preset reference voltage.

[0011] Preferably, the first signal driving circuit further includes: The switch driver circuit is configured to output a switch drive signal; A switching circuit, electrically connected to the switch driving circuit and the buck processing circuit respectively, and also electrically connected to the first CC line, is configured to respond to the input of the switch driving signal, and under the action of the buck signal, output the first voltage to the voltage comparison circuit through the first CC line, wherein the voltage amplitude of the buck signal is proportional to the first voltage.

[0012] Optionally, the reference voltage output circuit is a power management chip.

[0013] Optionally, the voltage comparison circuit includes a second voltage comparator, the positive terminal of which is electrically connected to the first CC line, and the negative terminal of which is electrically connected to the second CC line. The second voltage comparator is configured to receive a first voltage transmitted by the first CC line and a second voltage transmitted by the second CC line, respectively, and output a low-level first comparison signal in response to the first voltage being less than the second voltage, or output a high-level second comparison signal in response to the first voltage being greater than the second voltage.

[0014] In a second aspect, embodiments of this application provide an electronic device including the aforementioned water vapor detection circuit.

[0015] The embodiments of this application can achieve the following technical effects: This method implements moisture detection for the Type-C interface using as few circuits as possible, without adding external circuits, changing the Type-C interface structure, using a high-precision ADC, and reducing the requirements for the power management chip, making it feasible in most scenarios. Attached Figure Description

[0016] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0017] Figure 1 A schematic diagram of the circuit structure of a water vapor detection circuit provided in an embodiment of this application; Figure 2 A schematic diagram of the circuit structure of a first current source circuit provided for another embodiment of this application; Figure 3 A schematic diagram of the circuit structure of a first voltage processing circuit provided in another embodiment of this application; Figure 4 A schematic diagram of the circuit structure of a delay processing circuit provided in another embodiment of this application; Figure 5 A detailed circuit diagram of a delay processing circuit provided in yet another embodiment of this application; Figure 6 Reference signal timing for a delay processing circuit provided in yet another embodiment of this application; Figure 7 A schematic diagram of the circuit structure of a step-down processing circuit provided in another embodiment of this application; Figure 8 A detailed circuit diagram of a step-down processing circuit provided in yet another embodiment of this application; Figure 9A schematic diagram of the circuit structure of a feedback processing circuit provided in another embodiment of this application; Figure 10 A schematic diagram of the circuit structure of a first signal driving circuit provided in another embodiment of this application; Figure 11 A detailed circuit diagram of a first signal driving circuit provided in yet another embodiment of this application; Figure 12 This is a schematic diagram of the output of two sets of CC lines provided in one embodiment of this application; Figure 13 This is a schematic diagram of the output of two sets of CC lines provided in another embodiment of this application; Figure 14 This is a schematic diagram of the output of two sets of CC lines provided in yet another embodiment of this application. Detailed Implementation

[0018] To facilitate understanding of this application, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as being "fixed to" another element, it can be directly on the other element, or one or more intermediate elements may exist between them. When an element is described as being "electrically connected" to another element, it can be directly connected to the other element, or one or more intermediate elements may exist between them. The terms "upper," "lower," "inner," "outer," "bottom," etc., used in this specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0019] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items. Furthermore, technical features involved in the different embodiments of this application described below may be combined with each other as long as they do not conflict with each other.

[0020] This application provides a water vapor detection circuit. Please refer to [link / reference]. Figure 1The water vapor detection circuit 100 includes a signal source circuit 200, a first current source circuit 300, a first CC line 400, a Type-C interface 500, and a voltage comparison circuit 600. The Type-C interface 500 includes a second CC line 501, an impedance equivalent circuit 502, and a second current source circuit 503. The signal source circuit 200, the first current source circuit 300, and the voltage comparison circuit 600 are sequentially electrically connected, and a first voltage is transmitted to the voltage comparison circuit 600 via the first CC line 400. The impedance equivalent circuit 502 and the second current source circuit 503 in the Type-C interface 500 are sequentially electrically connected via the second CC line 501. The second current source circuit 503 is also electrically connected to the voltage comparison circuit 600 after being electrically connected to the signal source circuit 200, and a second voltage is transmitted to the voltage comparison circuit 600 via the second CC line 501.

[0021] The signal source circuit 200 is configured to output a driving voltage. The signal source circuit 200 can be a DC signal source (DC voltage or current source), a pulse signal source, or a constant power signal source, etc. The DC signal source can measure the change of resistance with humidity through DC excitation (when the humidity increases, the resistance of the humidity-sensitive resistor usually decreases or increases), and has the advantages of simple circuit and stable output, and is compatible with resistive water vapor sensors.

[0022] The first current source circuit 300 is electrically connected to the signal source circuit 200 and is configured to output a first voltage in response to the input of the driving voltage. The first current source circuit 300 can be an Rp resistor current source (upstream device, such as a charger or host computer), an Rd / Ra detection current source (driving downstream device, such as a mobile phone or peripheral device), etc. The upstream device (Source, such as a charger or computer host computer) outputs a specific current to the CC line through the Rp resistor and the current source, which is used to inform the downstream device of its own power supply capability. The Rp resistor current source includes a fixed current source and an Rp resistor network. A constant current (usually 80μA~330μA, depending on the Rp resistance value) is provided by a reference current source (such as a constant current source composed of a precision operational amplifier and a transistor). The current flowing through the Rp resistor generates a voltage signal. Different power supply capabilities are indicated by switching the Rp resistance value (such as using a MOSFET to select different resistors), which has strong compatibility. Downlink devices (Sinks, such as mobile phones and USB flash drives) use the Rd / Ra resistor on the CC line in conjunction with a current source to detect the Rp signal of the uplink device and provide feedback on their own status (such as whether they support charging or whether they are audio devices). For example, the Rd resistor pulls down the current source by connecting an Rd resistor (defined as Rd=5.1kΩ in the specification) between the CC line and ground in the downlink device. This forms a voltage divider with the Rp current source of the uplink device, generating a detection voltage of approximately 0.4V-0.6V (marking "this is a Sink device that requires power"). This current source is driven by the Rp current source of the uplink device, and the current flowing through Rd is approximately (Rp terminal voltage) / Rd, typically in the range of 100μA-300μA. This is used by MCUs or dedicated chips to detect the CC line level and identify the connection status.

[0023] The first CC line 400 is electrically connected to the first current source 300 and is configured to transmit the first voltage. The CC line, short for Configuration Channel, is the core signal line for intelligent identification and protocol negotiation in the Type-C interface, primarily used for connection configuration, power negotiation, and positive / negative insertion detection. The CC line transmits low-rate control signals (not high-speed data), typically at the tens of kbps level, prioritizing signal stability and anti-interference capabilities to prevent errors during negotiation. The transmitted signal type is a "single-ended signal" (not a high-speed differential signal), and communication is achieved through level changes in the pull-up resistors (Rp / Rd). The circuit structure is simple, low-cost, and easy to implement.

[0024] The Type-C interface 500 inherently contains two sets of CC lines. The second CC line 501 is connected to the Type-C interface (not shown in the figure) and responds to external moisture intrusion; this is called the normal CC line. When external moisture intrudes, the second CC line 501 generates a micro-short circuit to ground, which can be considered as generating an impedance equivalent circuit 502. The impedance equivalent circuit 502 can include the equivalent capacitance or short-circuit resistance generated by the micro-short circuit of the second CC line to ground. The first CC line 400 can serve as a mirror image of the normal CC line, used to restore the state of the normal CC line when there is no moisture intrusion; this is called the mirror CC line. The output voltages of the mirror CC line and the normal CC line to the voltage comparison circuit must be significantly different. This avoids misjudgment caused by slight changes in the output voltage leading to a high-level output from the voltage comparison circuit 600; it also prevents misjudgment caused by a lower output voltage of the normal CC line due to poor manufacturing processes. Understandably, the greater the difference in output voltage between the two sets of CC lines, the greater the tolerance for voltage output variations.

[0025] The second current source circuit 503 is electrically connected to the signal source circuit 200 and the second CC line 501, respectively, and is configured to transmit a target current through the second CC line 501 in response to the input of the driving voltage. The target current flows through the impedance equivalent circuit to generate a second voltage in the impedance equivalent circuit.

[0026] The voltage comparison circuit 600 is electrically connected to the first CC line 400 and the second CC line 501, respectively, and is configured to receive a first voltage transmitted by the first CC line 400 and a second voltage transmitted by the second CC line 501. When the first voltage is less than the second voltage, the voltage comparison circuit 600 outputs a first comparison signal; or, when the first voltage is greater than the second voltage, it outputs a second comparison signal. Due to the presence of the equivalent capacitance to ground or short-circuit resistance in the impedance equivalent circuit 502, the second voltage output by the second CC line 501 decreases, which may cause the first voltage to be greater than the second voltage at a certain moment. At this time, the voltage comparison circuit 600 outputs a high level (second comparison signal), indicating that moisture intrusion has been detected. Therefore, the first comparison signal is used to indicate that the moisture erosion level of the Type-C interface is lower than a preset level, and the second comparison signal is used to indicate that the moisture erosion level of the Type-C interface is higher than a preset level.

[0027] Please see Figure 2In some embodiments, the first current source circuit 300 includes a reference voltage output circuit 3001 and a first voltage processing circuit 3002. The reference voltage output circuit 3001 is configured to output a custom target reference voltage; the first voltage processing circuit 3002 is electrically connected to the reference voltage output circuit 3001 and the signal source circuit 200, respectively, and is electrically connected to the voltage comparator circuit 600 via a first CC line 400. It is configured to output a first voltage to the voltage comparator circuit via the first CC line 400 in response to the input of the target reference voltage, wherein the target reference voltage is proportional to the first voltage.

[0028] The reference voltage output circuit 3001 can output a custom target reference voltage to the first voltage processing circuit 3002. In some embodiments, the reference voltage output circuit 3001 includes one or more circuits with adjustable output voltage parameters, such as a delay control circuit and a buck control circuit. The voltage processing circuit 3002 is driven by the signal source circuit 200 and transmits a first voltage to the voltage comparison circuit 600 through the first CC line 400. In some embodiments, the target reference voltage is proportional to the first voltage, and the first voltage can be controlled by feedback from the target reference voltage. Preferably, the reference voltage output circuit 3001 includes a power management chip, which can realize functions such as system monitoring and communication.

[0029] In some embodiments, the first voltage processing circuit 3002 further includes a delay processing circuit 301, a buck processing circuit 302, and a first signal driving circuit 303. (See also...) Figure 3 The delay processing circuit 301 is electrically connected to the reference voltage output circuit 3001 and the signal source circuit 200, respectively, and can generate a delay signal in response to the input of the driving voltage and the first reference voltage. The voltage amplitude of the delay signal is inversely proportional to the first reference voltage.

[0030] The step-down processing circuit 302 is electrically connected to the delay processing circuit 301 and is configured to output a step-down signal in response to the input of the delay signal. The voltage amplitude of the step-down signal is proportional to the voltage amplitude of the delay signal.

[0031] After the first signal driving circuit 303 is electrically connected to the step-down processing circuit 302, it is also electrically connected to the first CC line 400. In response to the input of the step-down signal, it can output a first voltage to the voltage comparison circuit 600 through the first CC line 400. The voltage amplitude of the step-down signal is proportional to the first voltage.

[0032] In some embodiments, the delay processing circuit 301 further includes an integrator circuit 3011 and a first voltage comparator 3012. See also... Figure 4, the integrating circuit 3011 is electrically connected to the reference voltage output circuit 3001 and the signal source circuit 200 respectively, and can respond to the input of the driving voltage, perform integration processing on the driving voltage to obtain an integrated voltage. The positive electrode of the first voltage comparator 3012 is electrically connected to the integrating circuit 3011, the negative electrode of the first voltage comparator 3012 is electrically connected to the reference voltage output circuit 3001, the output terminal of the first voltage comparator 3012 is electrically connected to the step-down processing circuit 302, and is configured to output a high level in response to the integrated voltage being greater than the first reference voltage, or output a low level in response to the integrated voltage being less than the first reference voltage.

[0033] For example, please refer to Figure 5 , the integrating circuit 3011 may include a first operational amplifier U1, an integrating capacitor C1, a current-limiting resistor R1, etc. The input voltage V1 of the signal source circuit 200 is connected to the inverting input terminal of U1 via R1, so as to generate an input to the inverting input terminal of U1. Meanwhile, C2 is connected in parallel with the inverting input terminal of U1, and the non-inverting input terminal of U1 is grounded. When the input voltage is at a high level, current charges C1 via R1, and at this time, the output voltage V2 of U1 decreases linearly with time; when the input voltage is at a low level, the charging process stops, and V2 maintains the current potential.

[0034] as Figure 5 shows, the non-inverting input terminal of the first voltage comparator 3012 is electrically connected to the output terminal of U1, the inverting input terminal of the first voltage comparator 3012 is electrically connected to the reference voltage output circuit 3001, and the output terminal of the first voltage comparator 3012 is electrically connected to the step-down processing circuit 302. When the integrated voltage is greater than the first reference voltage Vref_1, the first voltage comparator 3012 outputs a high level; or, when the integrated voltage is less than the first reference voltage Vref_1, the first voltage comparator 3012 outputs a low level. Therefore, only when the output voltage V2 (the integrated voltage) of the integrating circuit 3011 drops to satisfy V2<Vref_1 can a rising edge be generated at the input terminal of the step-down processing circuit 302; since the input voltage at the inverting terminal of U1 starts to drop linearly with time from the rising edge of the input voltage V1 of the signal source 200, the time difference for it to drop to Vref_1 is the time that the rising edge of V2 lags behind V1 (that is, the delay time). The lower Vref_1 is, the more V2 needs to drop (the longer the charging time) to be lower than Vref_1, and the longer the delay time will be. For example, the timing of the reference signal of the delay processing circuit 301 is as shown in Figure 6 It can be understood that, in this embodiment, the sensitivity to the detection degree of water vapor intrusion can be adjusted by adjusting the magnitude of the reference voltage Vref_1.

[0035] In some embodiments, the buck processing circuit 302 includes a delay drive circuit 3021, a buck circuit 3022, and a feedback drive circuit 3023. See also... Figure 7 The delay drive circuit 3021 is electrically connected to the delay processing circuit 301 and is configured to output a delay drive signal in response to the input of the delay signal.

[0036] Please see Figure 8 For example, the delay drive circuit 3021 may include switching transistors Q1 and Q2, resistors Rp1 and Rp2.

[0037] The buck circuit 3022 is electrically connected to the delay drive circuit 3021 and the first signal drive circuit 303, respectively, and is configured to output a buck signal in response to the input of the delay signal. The voltage amplitude of the buck signal is proportional to the voltage amplitude of the delay signal. The buck circuit 3022 can be a buck circuit, including at least a main switch Q3, an inductor L1, a diode D1, a capacitor C2, and a resistor R2. The main switch Q3 can be a MOSFET, and its channel type can be P-channel or N-channel. Q3 is controlled by the input signal of its control module. When Q3 is on, L1 is charged, and power is supplied to the subsequent load. When the main switch is off, L1 is released through D1, maintaining the output voltage V3 unchanged. Preferably, the buck circuit 3022 may also include a filter capacitor C2 to filter out the high-frequency ripple generated by the switching action and smoothly output V3.

[0038] The feedback drive circuit 3023 is electrically connected to the buck circuit 302 and is configured to sample the buck signal output by the buck circuit, controlling the operating state of the buck circuit based on the buck signal. In some embodiments, the target reference voltage includes a second reference voltage. The feedback drive circuit 3023 further includes a sampling circuit 3231, a buck comparator circuit 3232, and a pulse generation circuit 3233. Please refer to [link to relevant documentation]. Figure 9 The sampling circuit 3231 is electrically connected to the buck circuit 3022 and is configured to sample the buck signal output by the buck circuit to obtain the sampled voltage. For example, the sampling circuit 3231 may include a voltage divider network composed of multiple voltage-dividing sampling resistors.

[0039] Please combine Figure 8 The voltage divider network includes R3 and R4, which are used to sample V3 proportionally, and can reduce the high voltage before sending it to the buck comparator circuit 3232.

[0040] The buck comparator circuit 3232 is electrically connected to the sampling circuit 3231 and is configured to output a comparison voltage in response to the input of the sampling voltage and the second reference voltage. Exemplarily, the buck comparator circuit 3232 includes a comparator U3 consisting of at least one operational amplifier. The inverting input of U3 is used to receive the sampling voltage, and the non-inverting input of U3 is used to receive a second reference voltage Vref_2, which is different from the first reference voltage. The output of U3 outputs a comparison voltage to the pulse generation circuit 3233 in response to the sampling voltage and Vref_2.

[0041] The pulse generation circuit 3233 is electrically connected to both the buck comparator circuit 3232 and the buck circuit 3022. Responding to the comparison voltage output by the buck comparator circuit 3232 and the preset reference voltage, it outputs a pulse drive signal to the buck circuit 3022. Exemplarily, the pulse generation circuit 3233 includes at least one PWM (Pulse Width Modulation) circuit. The negative terminal of the PWM circuit is electrically connected to the output terminal of U3 to receive the output signal from U3; the positive terminal of the PWM circuit is used to output the preset reference voltage. Exemplarily, the output terminal of the PWM circuit is electrically connected to the control pin of the main switch Q3 in the buck circuit 3022, to input a square wave signal with an adjustable duty cycle to Q3, controlling the on / off time of Q3, and thus adjusting the magnitude of V3 (the larger the duty cycle, the higher the output voltage). U3 compares the sampled V3 with Vref_2 and outputs an error signal, dynamically adjusting the duty cycle of the PWM circuit to achieve voltage regulation, ultimately enabling the buck circuit 3022 to stably output an output voltage V3 proportional to the amplitude of the delay signal. Similarly, by adjusting the magnitude of the reference voltage Vref_2, the sensitivity of water vapor detection can be adjusted. When multiple reference voltages exist simultaneously in the embodiments (for example, Vref_1 and Vref_2 exist simultaneously in some embodiments), the processor can adjust the sensitivity of water vapor detection in multiple ways and from multiple angles by adjusting the magnitudes of multiple reference voltages at the same time.

[0042] In some embodiments, the first signal driving circuit 303 further includes a switch driving circuit 3031 and a switch circuit 3032. (See also...) Figure 10 The switch driver circuit 3031 is electrically connected to the switch circuit 3032 and can output a switch drive signal to the switch circuit 3032; for example, please refer to Figure 11 The switch drive circuit 3031 includes a DC input power supply and at least one operational amplifier U4; the inverting input terminal of U4 is electrically connected to the DC input power supply, and the output terminal of U4 outputs a switch drive signal in response to the DC input power supply; preferably, the switch drive circuit 3031 may further include a voltage divider network composed of at least two current-limiting or voltage-dividing resistors, such as... Figure 11As shown, R5 is a current-limiting and voltage-dividing resistor, used to limit the current input to the inverting terminal of U4. At the same time, it works with the voltage-dividing resistor R6 to divide the voltage of V4, thereby setting the input voltage range of the preamplifier and preventing the power supply input voltage from being too high and damaging U4.

[0043] In addition to being electrically connected to the switch drive circuit 3031, the switch circuit 3032 is also electrically connected to the buck processing circuit 302 and the first CC line 400. Responding to the input of the switch drive circuit 3031, under the action of the buck signal, it outputs a first voltage to the voltage comparison circuit through the first CC line 400, wherein the voltage amplitude of the buck signal is proportional to the first voltage. For example, the switch circuit 3032 includes at least one switch transistor Q4, a feedback compensation capacitor C3, and a feedback resistor R8. Q4 can be a transistor, MOSFET, IGBT, etc.; understandably, Q4 can be an NPN transistor or a PNP transistor. The base current controls the collector-emitter conduction level, thereby adjusting the output first voltage. The feedback compensation capacitor C3 can suppress high-frequency oscillations in the circuit and increase system stability (e.g., compensating for the phase margin of U4 to avoid self-oscillation). The feedback resistor R8 can proportionally feed the output first voltage back to the non-inverting input of U4, comparing it with the input voltage at the inverting input to form "voltage negative feedback," stabilizing the output first voltage. Preferably, the switching circuit 3032 may further include a current-limiting resistor R7, which is electrically connected to the output terminal of U4 and the control terminal of Q4, respectively, to limit the current output from U4 to them, and at the same time protect U4 and Q4. Preferably, the switching circuit 3032 may further include current sampling resistors Rs and RL, which are connected in series in the load circuit to convert the load current into a voltage signal for current feedback control.

[0044] In some embodiments, the reference voltage output circuit 3001 is a power management chip. Using a power management chip, multiple reference voltages, including a delayed reference voltage and a buck reference voltage, can be adjusted simultaneously, enabling multi-mode and multi-angle adjustment of the moisture detection sensitivity. Power management integrated circuits (PMICs) have advantages such as high efficiency, high integration, high stability, and low power consumption, and can realize core functions such as power conversion and power management. Power conversion types include buck, boost, buck-boost, and AC / DC conversion; power management functions include timing control, dynamic voltage regulation, and power path management. For example, in a complex power management chip, the control delay circuit and buck circuit often work together; a typical workflow might include: (1) Enable and timing: The enable signal of a chip may itself have a delay. Alternatively, the output voltage "good" signal of a buck circuit (such as powering the CPU core) may be used as the "enable" signal of another buck circuit (such as powering I / O), and may be further delayed by a control delay circuit.

[0045] (2) Soft start: After the buck circuit is enabled, its internal soft start circuit (a special kind of delay control) starts to work. It does not immediately raise the output voltage to the target value, but controls the reference voltage or error amplifier to make the output voltage rise slowly over a few milliseconds. This is itself a kind of "delay control of voltage build-up process".

[0046] (3) Stable operation: After the soft start is completed, the buck circuit enters a stable PWM switching state to maintain a precise output voltage.

[0047] This application provides an electronic device, including one or more of the water vapor detection circuits described in all the above embodiments.

[0048] In some embodiments, the voltage comparison circuit 600 includes at least one second voltage comparator, the positive terminal of which is electrically connected to the first CC line 400, and the negative terminal of which is electrically connected to the second CC line 501. The second voltage comparator receives a first voltage transmitted through the first CC line 400 and a second voltage transmitted through the second CC line 501, and outputs a low-level first comparison signal in response to the first voltage being less than the second voltage; or, outputs a high-level second comparison signal in response to the first voltage being greater than the second voltage.

[0049] In some embodiments, there is no moisture intrusion, and the outputs of the two sets of CC lines are as follows: Figure 12 As shown, the second voltage comparator outputs a low level at this time, where the first voltage is slightly lower than the second voltage and there is a delay compared to the second voltage. The advantage of this is that it ensures that the voltage comparator circuit 600 will only output a high level when there is a micro-short circuit capacitor and resistor on the normal CC line. In other embodiments, the second CC line 501 is micro-short-circuited to ground due to moisture intrusion, generating an equivalent capacitance, causing the rise rate of the second voltage to be slower than the first voltage. Therefore, when the first voltage is greater than the second voltage at a certain moment, the second voltage comparator outputs a high-level pulse, which can be captured by the power management chip, with the effect as shown... Figure 13 As shown; in other embodiments, the second CC line 501 generates a short-circuit resistance to ground due to the micro-short circuit caused by moisture intrusion, which reduces the resistance on the second CC line 501, and ultimately reduces the output second voltage, which is lower than the first voltage. At this time, the comparator will also output a high level, which can be captured by the power management chip, with the effect as follows. Figure 14 As shown.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of this application as described above, which are not provided in detail for the sake of brevity; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A water vapor detection circuit, characterized in that, include: The signal source circuit is configured to output the drive voltage; A first current source, electrically connected to the signal source circuit, is configured to output a first voltage in response to the input of the driving voltage; The first CC line is electrically connected to the first current source and is configured to transmit the first voltage; A Type-C interface, including a second CC line, wherein the Type-C interface generates an impedance equivalent circuit when exposed to moisture, and the impedance equivalent circuit is electrically connected to the second CC line; The second current source, electrically connected to the signal source circuit and the second CC line respectively, is configured to transmit a target current through the second CC line in response to the input of the driving voltage. The target current flows through the impedance equivalent circuit to generate a second voltage in the impedance equivalent circuit. A voltage comparison circuit, electrically connected to the first CC line and the second CC line respectively, is configured to receive a first voltage transmitted by the first CC line and a second voltage transmitted by the second CC line respectively, and output a first comparison signal in response to the first voltage being less than the second voltage, or output a second comparison signal in response to the first voltage being greater than the second voltage, wherein the first comparison signal is used to indicate that the moisture erosion level of the Type-C interface is lower than a preset level, and the second comparison signal is used to indicate that the moisture erosion level of the Type-C interface is higher than a preset level; The first current source includes: The reference voltage output circuit is configured to output a custom target reference voltage; A first voltage processing circuit, electrically connected to the reference voltage output circuit and the signal source circuit respectively and electrically connected to the voltage comparison circuit through the first CC line, is configured to output the first voltage to the voltage comparison circuit through the first CC line in response to the input of the target reference voltage, wherein the target reference voltage is proportional to the first voltage; The target reference voltage includes a first reference voltage, and the first voltage processing circuit includes: The delay processing circuit is electrically connected to the reference voltage output circuit and the signal source circuit, respectively, and is configured to output a delay signal in response to the input of the driving voltage and the first reference voltage, wherein the voltage amplitude of the delay signal is inversely proportional to the first reference voltage; A step-down processing circuit, electrically connected to the delay processing circuit, is configured to output a step-down signal in response to the input of the delay signal, wherein the voltage amplitude of the step-down signal is proportional to the voltage amplitude of the delay signal. A first signal driving circuit, electrically connected to the buck processing circuit and also electrically connected to the first CC line, is configured to output the first voltage to the voltage comparison circuit through the first CC line in response to the input of the buck signal, wherein the voltage amplitude of the buck signal is proportional to the first voltage.

2. The water vapor detection circuit according to claim 1, characterized in that, The delay processing circuit includes: An integrating circuit, electrically connected to the reference voltage output circuit and the signal source circuit respectively, is configured to integrate the driving voltage in response to the input driving voltage to obtain an integrated voltage; A first voltage comparator, the positive terminal of which is electrically connected to the integrating circuit, the negative terminal of which is electrically connected to the reference voltage output circuit, and the output terminal of which is electrically connected to the buck processing circuit, is configured to output a high level in response to the integrated voltage being greater than the first reference voltage, or to output a low level in response to the integrated voltage being less than the first reference voltage.

3. The water vapor detection circuit according to claim 1, characterized in that, The step-down processing circuit includes: A delay drive circuit, electrically connected to the delay processing circuit, is configured to output a delay drive signal in response to the input of the delay signal; A step-down circuit, electrically connected to the delay drive circuit and the first signal drive circuit respectively, is configured to output a step-down signal in response to the input of the delay signal, wherein the voltage amplitude of the step-down signal is proportional to the voltage amplitude of the delay signal; A feedback drive circuit, electrically connected to the buck circuit, is configured to sample the buck signal output by the buck circuit and control the operating state of the buck circuit based on the buck signal.

4. The water vapor detection circuit according to claim 3, characterized in that, The target reference voltage includes a second reference voltage, and the feedback drive circuit includes: A sampling circuit, electrically connected to the step-down circuit, is configured to sample the step-down signal output by the step-down circuit to obtain a sampling voltage; A buck comparator circuit, electrically connected to the sampling circuit, is configured to output a comparison voltage in response to inputs of the sampling voltage and the second reference voltage; The pulse generation circuit is electrically connected to the buck comparator circuit and the buck circuit respectively, and is configured to output a pulse drive signal based on the comparison voltage and the preset reference voltage.

5. The water vapor detection circuit according to claim 1, characterized in that, The first signal driving circuit includes: The switch driver circuit is configured to output a switch drive signal; A switching circuit, electrically connected to the switch driving circuit and the buck processing circuit respectively, and also electrically connected to the first CC line, is configured to respond to the input of the switch driving signal, and under the action of the buck signal, output the first voltage to the voltage comparison circuit through the first CC line, wherein the voltage amplitude of the buck signal is proportional to the first voltage.

6. The water vapor detection circuit according to claim 1, characterized in that, The reference voltage output circuit is a power management chip.

7. The water vapor detection circuit according to any one of claims 1 to 6, characterized in that, The voltage comparison circuit includes a second voltage comparator, the positive terminal of which is electrically connected to the first CC line, and the negative terminal of which is electrically connected to the second CC line. The second voltage comparator is configured to receive a first voltage transmitted by the first CC line and a second voltage transmitted by the second CC line, respectively, and to output a low-level first comparison signal in response to the first voltage being less than the second voltage, or to output a high-level second comparison signal in response to the first voltage being greater than the second voltage.

8. An electronic device, characterized in that, Includes the water vapor detection circuit as described in any one of claims 1 to 7.

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