A TF card plug-in card detection circuit

Abstract

The utility model relates to circuit design technical field especially a TF card plug -in card detection circuit. In the detection circuit, along the circuit current direction includes the power supply, detection module, third resistance R3, disconnect or with third resistance R3 in parallel state's TF card operation module that set up in proper order in series, through the power consumption difference of detection TF card before and after insertion and work, realizes accurate detection to TF card plug -in card state.

Description

Technical Field

[0001] This utility model relates to the field of circuit design technology, and more specifically, to a TF card insertion detection circuit. Background Technology

[0002] Currently, some devices on the market require flip-type TF card slots. However, due to manufacturing limitations, these flip-type TF card slots lack card insertion detection pins. Therefore, the card insertion detection function in these devices using flip-type TF card slots is achieved by the system continuously reading the card. Using continuous card reading for TF card (TransFlash Card) insertion detection has the following problems: 1) Continuous card reading consumes significant system resources, affecting system speed; 2) During hot-swapping of the TF card, the system cannot determine whether the TF card is damaged or removed; 3) It increases device power consumption.

[0003] It is evident that in electronic devices, TF cards are commonly used storage expansion devices, and accurately detecting their insertion and removal status is crucial. Traditional TF card insertion detection methods suffer from problems such as inaccurate detection and complex circuitry.

[0004] There is an urgent need for a simple, reliable, and low-cost TF card insertion detection solution to meet the needs of various electronic devices for TF card status detection. Utility Model Content

[0005] This invention aims to provide a simple, reliable, and low-cost TF card insertion detection circuit to solve the technical problems in the background art. More specifically, this invention provides a TF card insertion detection circuit based on power consumption differences, which accurately detects the TF card insertion status by detecting the power consumption differences before and after TF card insertion and during operation.

[0006] The technical solution adopted by this utility model to solve its technical problem is:

[0007] A TF card insertion detection circuit, wherein the detection circuit includes, along the circuit current direction, a power supply 3V3, a detection module, a third resistor R3, and a TF card running module SD_VCC that is disconnected or in parallel with the third resistor R3;

[0008] The detection module includes a second resistor R2 and an amplifier chip U1;

[0009] The amplifier chip U1 has pins IN+, V+, GND, REF, OUT, and IN- arranged sequentially along the current direction. The amplifier chip U1 is connected in parallel with the second resistor R2 through pins IN+ and IN-. Pin V+ is grounded through capacitor C2; pin GND is grounded; pin REF is grounded.

[0010] The amplifier chip U1 has a pin OUT coupled to a voltage detection device ADC1, which is used to detect the output voltage of the amplifier chip U1 and determine the status of the TF card based on the value of the output voltage.

[0011] As an embodiment of this utility model, the amplification factor of the amplification chip U1 is 1000 times.

[0012] As an embodiment of this utility model, the voltage detection device ADC1 detects a maximum voltage of 3.3V.

[0013] As an embodiment of this utility model, when the output voltage of the amplifier chip U1 is >3.3V, a voltage divider circuit is also provided between the pin OUT and the voltage detection device ADC1.

[0014] As an embodiment of this utility model, the voltage divider circuit includes a first resistor R1 and a capacitor C1. The first end of the first resistor R1 is coupled to the pin OUT, and the second end of the first resistor R1 is grounded through the capacitor C1. The voltage detection device ADC1 is coupled to the second end of the first resistor R1 and is used to detect the output voltage of the first resistor R1.

[0015] As an embodiment of this utility model, the current output terminal of the third resistor is grounded.

[0016] As an embodiment of this utility model, the positive terminal of the power supply 3V3 is coupled to the detection module, and the negative terminal of the power supply 3V3 is grounded through capacitor C2.

[0017] As an embodiment of this utility model, when the TF card is inserted into the device, the TF card running module SD_VCC and the third resistor R3 are connected in parallel.

[0018] As an embodiment of this utility model, when the TF card is not inserted into the device, the TF card operation module SD_VCC is disconnected from the detection circuit.

[0019] As an embodiment of this utility model, the steps for determining the status of the TF card are as follows:

[0020] (1) Based on the values ​​of power supply 3V3, first resistor R1, second resistor R2, third resistor R3, capacitor C1, and capacitor C2, set the detection range of voltage detection device ADC1.

[0021] (2) When the voltage value detected by the voltage detection device ADC1 exceeds the detection range obtained in step (1), the TF card is determined to be in the read / write working state after insertion.

[0022] When the voltage value detected by the voltage detection device ADC1 falls within the detection range obtained in step (1), the TF card is determined to be in the inserted and standby state.

[0023] When the voltage value detected by the voltage detection device ADC1 is lower than the detection range obtained in step (1), the TF card is determined to be in the unplugged state.

[0024] The beneficial effects of this utility model are:

[0025] Compared to existing technologies, this invention accurately detects the TF card insertion status by detecting the power consumption difference before and after TF card insertion and during operation. Furthermore, by retaining only the ADC detection function, it consumes fewer system resources, reduces system power consumption, and improves system operating speed; it can accurately identify whether the TF card is damaged or has been removed, thus enabling hot-swapping of the TF card. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the TF card insertion detection circuit of this utility model;

[0027] Figure 2 This is a circuit diagram of a TF card insertion detection circuit according to an embodiment of the present invention.

[0028] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the present invention. To better illustrate the embodiments, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] This utility model provides a TF card insertion detection circuit, such as Figure 1 As shown, the detection circuit includes a power supply 3V3, a detection module, a third resistor R3, and a TF card operating module SD_VCC that is disconnected or connected in parallel with the third resistor R3, arranged in series along the circuit current direction. By detecting the power consumption difference before and after the TF card is inserted and during operation, the TF card insertion status can be accurately detected.

[0031] Specifically, when the TF card is inserted into the device, the TF card operation module SD_VCC is connected in parallel with the third resistor R3; when the TF card is not inserted into the device, the TF card operation module SD_VCC is disconnected from the detection circuit.

[0032] The specific mechanism is as follows: When the TF card is not inserted into the device, the circuit only connects the detection module and the third resistor R3 in series along the current direction. When the TF card is inserted into the device, the TF card operating module SD_VCC is in a connected state and connected to the TF card insertion detection circuit, and is connected in parallel with the third resistor R3. With the connection of the TF card operating module SD_VCC, the total resistance of the parallel resistor (the total resistance after R3 and SD_VCC are connected in parallel) in the circuit decreases. Compared with the resistance of the entire detection circuit when no TF card is inserted, the resistance decreases and the current increases. When the TF card is reading, it generates more energy, further reducing the resistance of the parallel resistor. The resistance of the entire detection circuit decreases further, and the current in the detection circuit reaches a greater level. Therefore, the working status of the TF card can be determined by the output voltage value of the detection module in the detection circuit.

[0033] Figure 2 The details of the components in the detection module are further provided in the text.

[0034] In a specific embodiment of this utility model, the detection module includes a second resistor R2 and an amplifier chip U1.

[0035] like Figure 2 As shown, the amplifier chip U1 has pins IN+, V+, GND, REF, OUT, and IN- arranged sequentially along the current direction. The amplifier chip U1 is connected in parallel with the second resistor R2 through pins IN+ and IN-. Pin V+ is grounded through capacitor C2; pin GND is grounded; and pin REF is grounded.

[0036] The amplifier chip U1 has a pin OUT coupled to a voltage detection device ADC1, which is used to detect the output voltage of the amplifier chip U1 and determine the status of the TF card based on the value of the output voltage.

[0037] exist Figure 2 In the circuit diagram shown, since the amplifier chip U1 and the second resistor R2 are connected in parallel, the IN+ / IN- voltage difference of the amplifier chip U1 is the same as the voltage across the second resistor R2. Through the grounding of the pins of the amplifier chip U1 and the connections of capacitors, the output voltage of the amplifier chip U1 detected by the voltage detection device ADC1 can be amplified by comparing it with the voltage across R2, allowing for sensitive monitoring of the TF card's operating status. The maximum amplification factor of the amplifier chip U1 can reach 1000 times.

[0038] In a specific embodiment of this utility model, for safety reasons, the voltage value detected by the voltage detection device ADC1 needs to be within a certain safe range, generally not exceeding 3.3V, to prevent voltage breakdown and damage to the equipment, and also to prevent high voltage from threatening the personal safety of the testing personnel.

[0039] In a specific embodiment of this utility model, when the output voltage of the amplifier chip U1 is >3.3V, a voltage divider circuit is also provided between the pin OUT and the voltage detection device ADC1.

[0040] like Figure 2 As shown in the specific embodiment of this utility model, the voltage divider circuit includes a first resistor R1 and a capacitor C1. The first end of the first resistor R1 is coupled to pin OUT, and the second end of the first resistor R1 is grounded through capacitor C1. The voltage detection device ADC1 is coupled to the second end of the first resistor R1 and is used to detect the output voltage of the first resistor R1. Capacitor C1 and resistor R1 form a filter circuit. In this way, the voltage at pin OUT in the circuit, after being shared by the first resistor R1, ensures that the voltage value at the current output terminal of R1 falls within a detectable safe range.

[0041] In a specific embodiment of this utility model, the current output terminal of the third resistor is grounded, and the potential of the ground terminal is 0V, which can ensure that the current in the detection circuit flows from the detection module to R3.

[0042] In a specific embodiment of this utility model, the positive terminal of the power supply 3V3 is coupled to the detection module, and the negative terminal of the power supply 3V3 is grounded through capacitor C2.

[0043] In a specific embodiment of this utility model, the specific steps for determining the status of the TF card are as follows:

[0044] (1) Based on the values ​​of power supply 3V3, first resistor R1, second resistor R2, third resistor R3, capacitor C1, and capacitor C2, set the detection range of voltage detection device ADC1.

[0045] (2) When the voltage value detected by the voltage detection device ADC1 exceeds the detection range obtained in step (1), the TF card is determined to be in the read / write working state after insertion.

[0046] When the voltage value detected by the voltage detection device ADC1 falls within the detection range obtained in step (1), the TF card is determined to be in the inserted and standby state.

[0047] When the voltage value detected by the voltage detection device ADC1 is lower than the detection range obtained in step (1), the TF card is determined to be in the unplugged state.

[0048] In this utility model, Figure 2 The detection circuit diagram shown is a specific embodiment for determining the operating status of the TF card:

[0049] Figure 2 In the circuit shown, one end of the 3V3 power supply is grounded, and the other end is connected to the input of the second resistor R2. The current flows through R2 and is output to the next node: the node formed by the third resistor R3 and the TF card running module SD_VCC in parallel. By changing the different working states of the TF card, the main current flowing through the entire detection circuit can be changed. By connecting it in parallel with the second resistor, the voltage across R2 can be detected. By analyzing the voltage difference across R2, the state of the TF card can be determined.

[0050] More specifically:

[0051] (1) When the TF card is not inserted, the current flowing through R2 is 1.65mA, the IN+ / IN- voltage difference of the amplifier chip U1 is 825μV, and the voltage value of the OUT pin is 0.825V;

[0052] (2) When the TF card is inserted and the device is in standby mode, the current flowing through R2 increases to 1.65mA + 100μA = 1.75mA. The voltage difference between IN+ and IN- of the amplifier chip U1 is 875μV, and the voltage value output by the OUT pin becomes 0.875V.

[0053] (3) When the TF card is inserted and read / write is performed, the current flowing through R2 is 1.65mA + 300mA = 301.65mA, the IN+ / IN- voltage difference of the amplifier chip U1 is 0.15V, and the OUT pin output is a maximum voltage of 3.3V;

[0054] (4) By selecting appropriate R1, R2, C1, and C2, the system detection threshold is set between 0.825 and 0.875V. If the voltage value detected by ADC1 is between 0.825 and 0.875V, it indicates that the TF card is inserted but not working. If the voltage value detected by ADC1 exceeds 0.875V, it is determined that the TF card is inserted and in read / write mode. If the voltage value detected by ADC is below 0.825V, it is determined that the TF card has been removed.

[0055] As can be seen, this utility model achieves accurate detection of the TF card insertion status by detecting the power consumption difference before and after the TF card is inserted and during operation.

[0056] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A TF card insertion detection circuit, characterized in that, The detection circuit includes, along the circuit current direction, a power supply 3V3, a detection module, a third resistor R3, and a TF card running module SD_VCC that is either disconnected or in parallel with the third resistor R3; The detection module includes a second resistor R2 and an amplifier chip U1; The amplifier chip U1 has pins IN+, V+, GND, REF, OUT, and IN- arranged sequentially along the current direction. The amplifier chip U1 is connected in parallel with the second resistor R2 through pins IN+ and IN-. Pin V+ is grounded through capacitor C2; pin GND is grounded; pin REF is grounded. The amplifier chip U1 has a pin OUT coupled to a voltage detection device ADC1, which is used to detect the output voltage of the amplifier chip U1 and determine the status of the TF card based on the value of the output voltage.

2. The TF card insertion detection circuit according to claim 1, characterized in that, The amplification factor of the amplification chip U1 is 1000 times.

3. The TF card insertion detection circuit according to claim 1, characterized in that, The maximum voltage detected by the voltage detection device ADC1 is 3.3V.

4. The TF card insertion detection circuit according to claim 1, characterized in that, When the output voltage of the amplifier chip U1 is >3.3V, a voltage divider circuit is also provided between the pin OUT and the voltage detection device ADC1.

5. The TF card insertion detection circuit according to claim 4, characterized in that, The voltage divider circuit includes a first resistor R1 and a capacitor C1. The first end of the first resistor R1 is coupled to the pin OUT, and the second end of the first resistor R1 is grounded through the capacitor C1. The voltage detection device ADC1 is coupled to the second end of the first resistor R1 and is used to detect the output voltage of the first resistor R1.

6. The TF card insertion detection circuit according to claim 1, characterized in that, The current output terminal of the third resistor is grounded.

7. The TF card insertion detection circuit according to claim 1, characterized in that, The positive terminal of the 3V3 power supply is coupled to the detection module, and the negative terminal of the 3V3 power supply is grounded through capacitor C2.

8. The TF card insertion detection circuit according to claim 1, characterized in that, When the TF card is inserted into the device, the TF card operation module SD_VCC is connected in parallel with the third resistor R3.

9. The TF card insertion detection circuit according to claim 1, characterized in that, When the TF card is not inserted into the device, the TF card operation module SD_VCC is disconnected from the detection circuit.

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