A type-c interface waterproof protection circuit adopting ad detection

Abstract

A kind of Type-C interface waterproof protection circuit using AD detection, including triode Q23 and triode Q24, the emitter of the triode Q23 is connected with power supply +3.3V, the collector of the triode Q23 is connected with the AD detection pin of MCU by KEY pin, the emitter of the triode Q24 is respectively connected with the base of triode Q23 and power supply +3.3V, the collector of the triode Q24 is connected with the collector of triode Q23, the base of the triode Q24 is respectively connected with power supply +3.3V and the A8 pin of Type-C interface, the B8 pin of Type-C interface is grounded.The utility model circuit is simple, low in cost, and high in reliability.

Description

Technical Field

[0001] This utility model relates to the field of electronic circuit technology, and in particular to a waterproof protection circuit for a Type-C interface using AD detection. Background Technology

[0002] Currently, many Bluetooth speakers and other consumer battery products on the market widely adopt Type-C interfaces, supporting PD fast charging, USB playback, and external charging. However, most Type-C interfaces lack waterproof detection circuitry. The current solution is to use self-developed chips, but this is costly, and in practice, it has been found that the comparators are susceptible to temperature and voltage variations, making them prone to malfunctions and unreliable. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a waterproof protection circuit for a Type-C interface using AD detection, which is simple, low in cost, and highly reliable.

[0004] To solve the above-mentioned technical problems, the technical solution of this utility model is: a waterproof protection circuit for a Type-C interface using AD detection, including transistors Q23 and Q24. The emitter of transistor Q23 is connected to the +3.3V power supply, and the collector of transistor Q23 is connected to the AD detection pin of the MCU through the KEY pin. The emitter of transistor Q24 is connected to both the base of transistor Q23 and the +3.3V power supply, and the collector of transistor Q24 is connected to the collector of transistor Q23. The base of transistor Q24 is connected to both the +3.3V power supply and pin A8 of the Type-C interface, and pin B8 of the Type-C interface is grounded. The principle of this utility model is to utilize the unused pins A8 and B8 on the Type-C interface. Pin A8 is on the front of the Type-C interface, and pin B8 is on the back. Pins A8 and B8 act as a water sensor. When water enters the Type-C interface, pins A8 and B8 are connected, the base of transistor Q24 is low, and transistor Q23 is connected, outputting +3.3V to the MCU AD detection pin through the KEY pin, controlling the machine to stop working and issuing a warning. When water does not enter the Type-C interface, pins A8 and B8 are not connected, the base of transistor Q24 is high, and transistor Q23 is cut off. The KEY pin outputs 0V to the MCU AD detection pin, and the machine works normally.

[0005] As an improvement, the +3.3V power supply is connected to pin A8 via resistors R128 and R131. A grounded capacitor C154 and a transient suppression diode D13 are located between resistors R128 and R131. A grounded transient suppression diode D14 is directly connected between resistor R131 and pin A8. A resistor R129 is located between the emitter and base of transistor Q23. The collectors of transistors Q23 and Q24 are connected to pin KEY via resistor R125. A grounded resistor R127 is located between resistor R125 and pin KEY. Pin B8 of the Type-C interface is grounded via resistor R135.

[0006] The beneficial effects of this utility model compared with the prior art are: 1. Active detection and protection: It can monitor whether water has entered the Type-C interface in real time, and immediately notify the MCU to take protective measures such as power-off when liquid is detected to prevent the damage from spreading; 2. Extremely low cost: The core circuit consists only of general-purpose transistors and resistors, eliminating the need for dedicated liquid sensors or complex sealing structures, which significantly reduces costs; 3. Ingenious design: It utilizes the unused pins of the Type-C interface as sensors, without occupying normal functional pins or affecting the original performance of the interface; 4. Rapid response: Based on transistor switching circuit, state switching is in the microsecond range, enabling rapid response; 5. High reliability: The circuit is simple, with few points of failure, and the status is clear (high / low level), which is easy for the MCU to judge. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of a waterproof protection circuit.

[0008] Figure 2 This is a schematic diagram of a waterproof protection circuit used in a charging circuit. Detailed Implementation

[0009] The present invention will be further described below with reference to the accompanying drawings.

[0010] like Figure 1 , 2As shown, a waterproof protection circuit for a Type-C interface using AD detection includes transistors Q23 and Q24. The emitter of transistor Q23 is connected to a +3.3V power supply, and the collector of transistor Q23 is connected to the AD detection pin of the MCU via the KEY pin. The emitter of transistor Q24 is connected to both the base of transistor Q23 and the +3.3V power supply, and the collector of transistor Q24 is connected to the collector of transistor Q23. The base of transistor Q24 is connected to both the +3.3V power supply and pin A8 of the Type-C interface, and pin B8 of the Type-C interface is grounded.

[0011] The +3.3V power supply is connected to pin A8 via resistors R128 and R131. A grounded capacitor C154 and a transient suppression diode D13 are located between resistors R128 and R131. A grounded transient suppression diode D14 is directly connected between resistor R131 and pin A8. A resistor R129 is located between the emitter and base of transistor Q23. The collectors of transistors Q23 and Q24 are connected to pin KEY via resistor R125. A grounded resistor R127 is located between resistor R125 and pin KEY. Pin B8 of the Type-C interface is grounded via resistor R135.

[0012] The principle of this invention is as follows: It mainly utilizes pins A8 and B8 on the Type-C interface. Pin A8 is on the front of the Type-C interface, and pin B8 is on the back. Pins A8 and B8 act as water sensors. When water enters the Type-C interface, pins A8 and B8 conduct, the base of transistor Q24 is low, and transistor Q23 conducts, outputting +3.3V to the MCU AD detection pin through the KEY pin, controlling the machine to stop working and issuing a warning. When no water enters the Type-C interface, pins A8 and B8 are not conducting, the base of transistor Q24 is high, and transistor Q23 is cut off. The KEY pin outputs 0V to the MCU AD detection pin, and the machine operates normally.

Claims

1. A waterproof protection circuit for a Type-C interface using AD detection, characterized in that: The device includes transistors Q23 and Q24. The emitter of transistor Q23 is connected to the +3.3V power supply, and the collector of transistor Q23 is connected to the AD detection pin of the MCU via the KEY pin. The emitter of transistor Q24 is connected to both the base of transistor Q23 and the +3.3V power supply, and the collector of transistor Q24 is connected to the collector of transistor Q23. The base of transistor Q24 is connected to both the +3.3V power supply and pin A8 of the Type-C interface, and pin B8 of the Type-C interface is grounded.

2. The waterproof protection circuit for a Type-C interface using AD detection according to claim 1, characterized in that: The +3.3V power supply is connected to pin A8 via resistors R128 and R131. A grounded capacitor C154 and a transient suppression diode D13 are located between resistors R128 and R131. A grounded transient suppression diode D14 is directly connected between resistor R131 and pin A8. A resistor R129 is located between the emitter and base of transistor Q23. The collectors of transistors Q23 and Q24 are connected to pin KEY via resistor R125. A grounded resistor R127 is located between resistor R125 and pin KEY. Pin B8 of the Type-C interface is grounded via resistor R135.

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