Broken line detection circuit of differential digital signal

Abstract

The utility model discloses a disconnection detection circuit for differential digital signals, which relates to the technical field of circuit detection and comprises a first optocoupler, a second optocoupler and a detection assembly. The anode of the first optocoupler illuminator is connected with one end of a differential signal, the cathode of the first optocoupler illuminator is connected with a differential signal ground wire, the collector of the first optocoupler light receptor is connected with a power supply, and the emitter of the first optocoupler internal light receptor is grounded; the anode of the second optocoupler illuminator is connected with the other end of the differential signal, the cathode of the second optocoupler illuminator is connected with the differential signal ground wire, the collector of the second optocoupler light receiver is connected with the power supply, and the emitter of the second optocoupler light receiver is grounded; collector electrodes of the light receivers in the first optical coupler and the second optical coupler are connected in parallel and then are connected with a detection port of the detection assembly. According to the utility model, whether the differential signal line is broken or not can be effectively identified, and the differential receiver is prevented from analyzing wrong signals and generating wrong data streams.

Description

Technical Field

[0001] The utility model relates to the technical field of circuit detection, in particular to a line break detection circuit for differential digital signals. Background Art

[0002] Digital differential signaling has been widely adopted in serial high-speed data communication applications due to its advantages such as low power consumption, low bit error rate, low crosstalk, and low radiation. These applications include digital communication between circuit boards and the digital interfaces of many sensors. However, since differential signaling uses the voltage difference between two signal lines to transmit logic states, if one line is broken, the high impedance of the broken line can easily cause interference and generate induced voltage. This can cause the differential receiver to interpret the signal as an erroneous signal, resulting in an erroneous data stream. Therefore, the ability to promptly and effectively identify signal line breaks becomes crucial. Utility Model Content

[0003] The technical problem to be solved by the utility model is to overcome the shortcomings of the prior art and provide a line break detection circuit for differential digital signals.

[0004] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0005] A line break detection circuit for a differential digital signal includes a first optocoupler, a second optocoupler, and a detection component;

[0006] The anode of the light emitter inside the first optocoupler is connected to one end of the differential signal, the cathode of the light emitter inside the first optocoupler is connected to the differential signal ground, the collector of the light receiver inside the first optocoupler is connected to the power supply, and the emitter of the light receiver inside the first optocoupler is grounded;

[0007] The anode of the light emitter inside the second optocoupler is connected to the other end of the differential signal, the cathode of the light emitter inside the second optocoupler is connected to the differential signal ground, the collector of the light receiver inside the second optocoupler is connected to the power supply, and the emitter of the light receiver inside the second optocoupler is grounded;

[0008] The collectors of the light receivers inside the first and second optical couplers are connected in parallel and then connected to the detection port of the detection component.

[0009] As a preferred solution of the differential digital signal disconnection detection circuit of the present invention, it further includes a first resistor connected between the collector of the light receiver inside the first optocoupler and the power supply.

[0010] As a preferred solution of the differential digital signal disconnection detection circuit of the present invention, it further includes a second resistor connected between the collector of the light receiver inside the second optocoupler and the power supply.

[0011] As a preferred solution of the differential digital signal disconnection detection circuit of the utility model, the detection component includes a single-chip microcomputer, and the collectors of the first and second optocoupler internal light receivers are connected in parallel to the IO pins of the single-chip microcomputer.

[0012] As a preferred solution of the differential digital signal disconnection detection circuit of the present invention, the model of the single chip microcomputer is STM32F103CBT6.

[0013] The beneficial effects of the utility model are:

[0014] (1) The present invention connects the two ends of the differential signal through two optocouplers, and then determines whether the differential signal is normal by whether the light receivers inside the two optocouplers are turned on. It can effectively identify whether the differential signal line is broken, and avoid the differential receiver parsing the wrong signal and generating an erroneous data stream. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0016] Figure 1 This is a schematic diagram of a differential digital signal disconnection detection circuit provided by the present invention. DETAILED DESCRIPTION

[0017] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific implementation methods and in conjunction with the accompanying drawings.

[0018] Figure 1 A schematic diagram of a line break detection circuit for a differential digital signal provided in an embodiment of the present application. The line break detection circuit for a differential digital signal includes a differential signal generator, a first optocoupler, a second optocoupler, a first resistor, a second resistor, and a detection component.

[0019] Specifically, the first optical coupler and the second optical coupler each include a light emitter and a light receiver.

[0020] Among them, see Figure 1The anode of the light emitter inside the first optocoupler is connected to one end of the differential signal generated by the differential signal generator, and the cathode of the light emitter inside the first optocoupler is connected to the differential signal ground. The collector of the light receiver inside the first optocoupler is connected in series with the first resistor R1 and then connected to the power supply, and the emitter of the light receiver inside the first optocoupler is grounded.

[0021] The anode of the light emitter inside the second optocoupler is connected to the other end of the differential signal generated by the differential signal generator, and the cathode of the light emitter inside the second optocoupler is connected to the differential signal ground. The collector of the light receiver inside the second optocoupler is connected in series with the second resistor R2 and then connected to the power supply. The emitter of the light receiver inside the first optocoupler is grounded.

[0022] The collectors of the light receivers inside the first optical coupler and the second optical coupler are connected in parallel and then connected to the detection port of the detection component.

[0023] When the differential signal is normal, the voltage difference between the differential signal line and the ground line causes the internal light emitters of the first and second optocouplers to light up, respectively, and the two optocoupler light receivers to conduct. Because the collectors of the two optocoupler light receivers are connected together, the detection device will detect a continuous low level. When any of the differential signals is broken, the corresponding optocoupler's internal light emitter goes out, the light receiver is cut off, and the collector of the light receiver is pulled up to the power supply potential by the resistor, and the detection device will detect a pulse signal.

[0024] In this embodiment, the detection component uses a single-chip microcomputer model STM32F103CBT6. The collectors of the internal light receptors of the first and second optocouplers are connected in parallel and connected to the IO pins of the single-chip microcomputer. Through this connection method, connecting the two signals together is equivalent to performing an OR operation. In this way, the two signals are combined together, and two sets of signals can be detected through a single pin. When the differential signal is normal, the output signal is a low level. If any input signal is disconnected, the output signal of the circuit becomes a pulse signal, or even a completely high level.

[0025] Therefore, the technical solution of the present application can effectively identify whether the differential signal line is broken, thereby preventing the differential receiver from parsing the wrong signal and generating an erroneous data stream.

[0026] In addition to the above embodiments, the present invention may also have other implementation methods; any technical solutions formed by equivalent replacement or equivalent transformation fall within the protection scope required by the present invention.

Claims

1. A line break detection circuit for a differential digital signal, characterized in that: It includes a first optical coupler, a second optical coupler and a detection component; The anode of the light emitter inside the first optocoupler is connected to one end of the differential signal, the cathode of the light emitter inside the first optocoupler is connected to the differential signal ground, the collector of the light receiver inside the first optocoupler is connected to the power supply, and the emitter of the light receiver inside the first optocoupler is grounded; The anode of the light emitter inside the second optocoupler is connected to the other end of the differential signal, the cathode of the light emitter inside the second optocoupler is connected to the differential signal ground, the collector of the light receiver inside the second optocoupler is connected to the power supply, and the emitter of the light receiver inside the second optocoupler is grounded; The collectors of the light receivers inside the first and second optical couplers are connected in parallel and then connected to the detection port of the detection component.

2. The differential digital signal disconnection detection circuit according to claim 1, wherein: The optical coupler further includes a first resistor connected between the collector of the light receiver inside the first optical coupler and the power supply.

3. The differential digital signal disconnection detection circuit according to claim 1, wherein: The optical coupler further includes a second resistor connected between the collector of the light receiver inside the second optical coupler and the power supply.

4. The differential digital signal disconnection detection circuit according to claim 1, wherein: The detection component includes a single-chip microcomputer, and the collectors of the light receivers inside the first optocoupler and the second optocoupler are connected in parallel and then connected to the IO pin of the single-chip microcomputer.

5. The differential digital signal disconnection detection circuit according to claim 4, wherein: The model of the single chip microcomputer is STM32F103CBT6.

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