Accurate input detection circuit

Abstract

The utility model relates to the technical field of signal detection, and particularly discloses a precise input detection circuit which comprises an input module, a detection module and a controller, a to-be-detected port IN is electrically connected to the input end of the input module, and the output end of the input module is electrically connected to the input end of the detection module; the output end of the detection module is electrically connected to the input port IRQ of the controller; the input module comprises a capacitor C2 and a to-be-detected port IN, the to-be-detected port IN is electrically connected to the positive electrode of the capacitor C2, the positive electrode of the capacitor C2 is electrically connected to the input end of the detection module, and the negative electrode of the capacitor C2 is grounded. The detection module can generate the high-level signal or the low-level signal according to the output of the input module, and outputs the generated signal to the controller, so that the voltage of the input signal can be detected more accurately.

Description

Technical Field

[0001] This application relates to the field of signal detection technology, and in particular to a precise input detection circuit. Background Technology

[0002] In circuits, it is important to accurately detect the threshold of the input signal voltage. By accurately detecting the voltage threshold, it can be ensured that the controller operates within the normal operating voltage range, avoiding damage or performance degradation of the controller caused by excessively high or low voltage.

[0003] Current circuit designs detect current values ​​by sensing the output voltage of a sampling resistor. This output voltage is then compared to two reference voltages to output two indicator signals, indicating whether the current is within a set value or abnormally exceeds it. Traditional detection methods involve continuous current sampling, resulting in complex subsequent processing circuitry and susceptibility to noise, which negatively impacts the accuracy of voltage threshold detection. Therefore, this application proposes a precise input detection circuit. Utility Model Content

[0004] To improve the detection accuracy of input signals, this application provides a precise input detection circuit.

[0005] This application provides a precise input detection circuit, which adopts the following technical solution:

[0006] A precise input detection circuit includes an input module, a detection module, and a controller. The port IN to be detected is electrically connected to the input terminal of the input module, and the output terminal of the input module is electrically connected to the input terminal of the detection module. The output terminal of the detection module is electrically connected to the input port IRQ of the controller. The input module includes a capacitor C2. The port IN to be detected is electrically connected to the positive terminal of the capacitor C2, and the positive terminal of the capacitor C2 is electrically connected to the input terminal of the detection module. The negative terminal of the capacitor C2 is grounded.

[0007] By adopting the above technical solution, when the detection port IN has no output, the input module has no output; when the detection port IN has an output, the output voltage of the detection port IN charges capacitor C2. When capacitor C2 is fully charged, the positive terminal of capacitor C2 can output voltage, at which time the input module has an output; the detection module can generate a high-level signal or a low-level signal according to the output of the input module, and output the generated signal to the controller, thereby enabling more accurate detection of the input signal voltage.

[0008] Preferably, the input module further includes a Zener diode Z1, the test port IN is electrically connected to the cathode of the Zener diode Z1, and the anode of the Zener diode Z1 is electrically connected to the anode of the capacitor C2.

[0009] By adopting the above technical solution, the Zener diode Z1 can achieve the functions of threshold setting and filtering. When the voltage value output by the detection port IN is continuously greater than the working threshold of the Zener diode Z1, the Zener diode Z1 can be turned on. At this time, the voltage output by the detection port IN can stably charge the capacitor C2, thereby further improving the accuracy of input signal voltage detection.

[0010] Preferably, the input module further includes a capacitor C1, the port IN to be detected is electrically connected to one end of the capacitor C1, and the other end of the capacitor C1 is grounded.

[0011] By adopting the above technical solution, capacitor C1 plays the role of port filtering, which can effectively filter out high-frequency noise and pulse interference of the IN output signal of the port to be tested, and improve the anti-interference capability of the circuit.

[0012] Preferably, the detection module includes a switching transistor Q1 and a power supply VCC; the control terminal of the switching transistor Q1 is electrically connected to the output terminal of the input module, the input terminal of the switching transistor Q1 is electrically connected to the input terminal IRQ of the controller, the output terminal of the switching transistor Q1 is grounded, and the voltage output terminal of the power supply VCC is electrically connected to the input terminal IRQ of the controller.

[0013] By adopting the above technical solution, when the output voltage of the input module cannot prevent the switching transistor Q1 from conducting, the voltage output value of the power supply VCC is output to the input terminal IRQ of the controller. At this time, the input terminal IRQ of the controller receives a high-level signal. When the output voltage of the input module can enable the switching transistor Q1 to conduct in the forward direction, the input terminal IRQ of the controller is grounded through the switching transistor Q1, and the input terminal IRQ of the controller receives a low-level signal.

[0014] Preferably, the detection module further includes a resistor R2, one end of which is electrically connected to the voltage output terminal of the power supply VCC, and the other end of which is electrically connected to the input terminal IRQ of the controller.

[0015] By adopting the above technical solution, the resistor R2 can be used to limit the current and prevent excessive current from damaging the controller.

[0016] Preferably, the switching transistor Q1 is an NPN transistor.

[0017] By adopting the above technical solution, NPN transistors can more effectively control the on / off state of switching circuits, thereby achieving more precise circuit control.

[0018] In summary, this application includes at least one of the following beneficial technical effects:

[0019] In the circuit, when the detection port IN has no output, the Zener diode Z1 is not turned on, the switching transistor Q1 cannot be turned on, and the controller's input terminal IRQ receives a high-level signal. When the output voltage of the detection port IN continuously reaches the turn-on voltage of the Zener diode Z1, the Zener diode Z1 turns on, and the output voltage of the detection port IN charges the capacitor C2 through the Zener diode Z1. When the capacitor C2 is fully charged, the positive terminal of the capacitor C2 can output voltage. When the voltage value of the positive terminal of the capacitor C2 is greater than the turn-on voltage value of the switching transistor Q1, the switching transistor Q1 turns on in the forward direction, and the controller's input terminal IRQ receives a low-level signal, thereby realizing the accurate detection of the input signal voltage. Attached Figure Description

[0020] Figure 1 This is the circuit diagram of this application.

[0021] Reference numerals: 1. Input module; 2. Detection module. Detailed Implementation

[0022] The following is in conjunction with the appendix Figure 1 This application will be described in further detail.

[0023] This application discloses a precise input detection circuit.

[0024] Reference Figure 1 A precise input detection circuit includes an input module 1, a detection module 2, and a controller, which are electrically connected in sequence. The port IN to be detected is electrically connected to the input terminal of the input module 1, and the output terminal of the input module 1 is electrically connected to the input terminal of the detection module 2. The output terminal of the detection module 2 is electrically connected to the input port IRQ of the controller. When the port IN to be detected outputs a low level, the input module 1 enables the detection module 2 to output a high level; when the port IN to be detected outputs a high level, the input module 1 enables the detection module 2 to output a low level. The controller can determine whether the port IN to be detected is outputting a low-level signal or a high-level signal based on whether it receives a high-level signal or a low-level signal, and output the generated signal to the controller, thereby enabling more accurate detection of the input signal voltage.

[0025] Input module 1 includes capacitor C2, resistor R1, and Zener diode Z1; the detection port IN is electrically connected to the cathode of Zener diode Z1, and the anode of Zener diode Z1 is electrically connected to the input terminal of detection module 2 through resistor R1; the positive terminal of capacitor C2 is set as the output terminal of input module 1, and the positive terminal of capacitor C2 is electrically connected to the input terminal of detection module 2, while the negative terminal of capacitor C2 is grounded; Zener diode Z1 can achieve the functions of threshold setting and filtering. The voltage value received by Zener diode Z1 needs to be continuously greater than its operating threshold in order to charge capacitor C2.

[0026] When the test port IN has no output, the Zener diode Z1 is not conducting, and input module 1 has no output. When the output voltage of the test port IN continuously reaches the conduction voltage value of the Zener diode Z1, the Zener diode Z1 conducts, and the output voltage of the test port IN charges the capacitor C2 stably through the Zener diode Z1. When the capacitor C2 is fully charged, the positive terminal of the capacitor C2 can output voltage, and input module 1 has output. If the output voltage of the test port IN is unstable or does not reach the set threshold of the Zener diode Z1, the Zener diode Z1 is not conducting, and input module 1 has no output.

[0027] Furthermore, input module 1 also includes capacitor C1. The cathode of Zener diode Z1 is electrically connected to one end of capacitor C1, and the other end of capacitor C1 is grounded. Capacitor C1 is a port filter capacitor, which can effectively filter out high-frequency noise and pulse interference from the IN output signal of the port to be detected, thereby improving the circuit's anti-interference capability.

[0028] The detection module 2 includes a switching transistor Q1, a power supply VCC, and a resistor R2. In this embodiment, the switching transistor Q1 is an NPN transistor. The base of the NPN transistor Q1 is electrically connected to the output terminal of the input module 1. The voltage output terminal of the power supply VCC is electrically connected to one end of the resistor R2, and the other end of the resistor R2 is electrically connected to the input terminal IRQ of the controller. The emitter of the NPN transistor Q1 is grounded, and the collector of the NPN transistor Q1 is electrically connected to the output terminal of the detection module 2, and the collector of the NPN transistor Q1 is also electrically connected to the input terminal IRQ of the controller. In this embodiment, the output voltage value of the power supply VCC is set to 3.3V or 5V.

[0029] When the output voltage of input module 1 is less than the turn-on voltage of NPN transistor Q1, NPN transistor Q1 cannot conduct. The output voltage of power supply VCC is then output to the controller's input terminal IRQ via resistor R2, at which point the controller's input terminal IRQ receives a high-level signal. When the output voltage of input module 1 is greater than the turn-on voltage of NPN transistor Q1, NPN transistor Q1 can conduct forward. The output voltage of power supply VCC is grounded via resistor R2 and NPN transistor Q1. At this time, the controller's input terminal IRQ is grounded through NPN transistor Q1, and the controller's input terminal IRQ receives a low-level signal. In this embodiment, NPN transistor Q1 functions as a switch.

[0030] The implementation principle of this application embodiment is as follows: In the circuit, when the port IN to be detected has no output, the Zener diode Z1 does not conduct because it has not reached its conduction voltage, and the base of the NPN transistor Q1 does not receive enough voltage to overcome the voltage drop between its base and emitter. Therefore, the NPN transistor Q1 also cannot conduct, and the input terminal IRQ of the controller receives a high-level signal.

[0031] When the output voltage of the port IN to be detected continuously reaches the turn-on voltage of the Zener diode Z1, the Zener diode Z1 turns on. The output voltage of the port IN charges the capacitor C2 through the Zener diode Z1. When the capacitor C2 is fully charged, its positive terminal voltage reaches a value sufficient to turn on the NPN transistor Q1 in the forward direction. At this time, the base of the NPN transistor Q1 receives a sufficient voltage to overcome the voltage drop between the base and emitter, and the NPN transistor Q1 begins to conduct. The turned-on NPN transistor Q1 pulls the controller input terminal IRQ to a low level, and the controller input terminal IRQ receives a low-level signal. Through the above, accurate detection of the input signal can be achieved.

[0032] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made to the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A precision input detection circuit, characterized by comprising: The system includes an input module (1), a detection module (2), and a controller. The port IN to be detected is electrically connected to the input terminal of the input module (1), and the output terminal of the input module (1) is electrically connected to the input terminal of the detection module (2). The output terminal of the detection module (2) is electrically connected to the input port IRQ of the controller. The input module (1) includes a capacitor C2. The port IN to be detected is electrically connected to the positive terminal of the capacitor C2, and the positive terminal of the capacitor C2 is electrically connected to the input terminal of the detection module (2). The negative terminal of the capacitor C2 is grounded.

2. The precise input detection circuit according to claim 1, wherein The input module (1) also includes a Zener diode Z1, the test port IN is electrically connected to the cathode of the Zener diode Z1, and the anode of the Zener diode Z1 is electrically connected to the anode of the capacitor C2.

3. The precise input detection circuit according to claim 1, wherein The input module (1) also includes a capacitor C1, the port IN to be detected is electrically connected to one end of the capacitor C1, and the other end of the capacitor C1 is grounded.

4. The precise input detection circuit according to claim 1, wherein The detection module (2) includes a switch Q1 and a power supply VCC; the control terminal of the switch Q1 is electrically connected to the output terminal of the input module (1), the input terminal of the switch Q1 is electrically connected to the input terminal IRQ of the controller, the output terminal of the switch Q1 is grounded, and the voltage output terminal of the power supply VCC is electrically connected to the input terminal IRQ of the controller.

5. The precise input detection circuit according to claim 4, wherein The detection module (2) also includes a resistor R2, one end of which is electrically connected to the voltage output terminal of the power supply VCC, and the other end of which is electrically connected to the input terminal IRQ of the controller.

6. The precise input detection circuit according to claim 4, wherein The switching transistor Q1 is set as an NPN transistor.

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