A digital signal isolator based on time division multiplexing to achieve multi-path transmission

Abstract

The application discloses a digital signal isolator based on time division multiplexing to realize multi-path transmission. The digital signal isolator comprises a signal transmitting module, an isolation channel and a signal receiving module. The signal transmitting module of the digital signal isolator periodically samples multi-path parallel input signals and modulates the signals into a serial data stream, and adds a flag signal bit at the beginning of each data stream. The serial data stream is transmitted from the signal transmitting module to the signal receiving module through an isolation channel. The receiving module of the digital signal isolator demodulates the data stream received from the isolation channel, recovers a clock through the starting flag signal, demodulates each signal by using the recovered clock, and then recovers parallel data from the serial data stream. The application has the following advantages: the application modulates multi-path signals into a signal for transmission, so that the utilization rate of the isolation channel can be improved, and the cost can be reduced.

Description

Technical Field

[0001] This invention relates to communication technology and digital isolation technology, specifically to a digital signal isolator that implements multiplexing based on time division multiplexing. Background Technology

[0002] Time division multiplexing (TDM) is a multiplexing method in the field of communications that places different signals in different time periods and transmits them along a single transmission path. At the signal receiving end, the signals from different time periods are extracted to achieve the transmission of multiple signals on the same path.

[0003] Digital signal isolators are widely used in automotive electronics, medical electronics, and industrial manufacturing to transmit data between two devices that are not electrically connected. A key feature of isolators is their ability to protect personnel and equipment, and to isolate noise. Currently, there are three main isolation methods: optical coupling isolation, capacitive isolation, and magnetic isolation. Different isolation methods have different advantages and disadvantages, and the choice must be made based on the application scenario and requirements. Common modulation methods for isolated communication include OOK modulation and pulse modulation. In traditional digital signal isolators, one data channel requires one isolation channel, and each data path undergoes independent modulation and demodulation. This means that for every additional signal transmission, an additional isolation channel is needed. This increases the area of ​​the isolation channels, making the entire isolator bulky. Summary of the Invention

[0004] This invention aims to propose a digital signal isolator based on time-division multiplexing for multi-channel transmission. This invention introduces a time-division multiplexing communication method into the digital signal isolator, modulating multiple signals into a single signal, thereby improving the utilization rate of the isolation channel, significantly reducing the area of ​​the digital signal isolator, and lowering costs. Through this innovation, we can achieve a more compact and efficient digital signal isolator design while maintaining signal isolation performance, further meeting the application needs of different fields.

[0005] To achieve this objective, the present invention provides the following technical solution:

[0006] This invention provides a digital signal isolator based on time-division multiplexing for multi-channel transmission, which includes a signal transmitting module, an isolation transmission channel, and a signal receiving module;

[0007] The signal transmission module includes a parallel-to-serial converter and a pulse modulation circuit;

[0008] The parallel-to-serial circuit described above converts multiple input parallel signals into a serial data stream;

[0009] The pulse modulation circuit modulates the high-order bits of the serial data stream into a pulse signal, and transmits the modulated signal to the signal receiving module through an isolated transmission channel.

[0010] The signal receiving module includes a pulse amplification and detection circuit, a pulse demodulation circuit, and a serial-to-parallel conversion circuit;

[0011] The pulse amplification and detection circuit amplifies and detects the signal received from the isolated transmission channel; the pulse demodulation circuit recovers the input signal from the pulse sequence amplified by the pulse amplification and detection circuit.

[0012] The serial-to-parallel conversion circuit is used to restore the serial data stream obtained by pulse demodulation by the pulse demodulation circuit into a multi-channel parallel output.

[0013] According to a preferred embodiment of the present invention, the signal transmitting module further includes a driving circuit, which is connected to the output of the parallel-to-serial circuit and to the input of the isolated transmission channel, and provides current to drive the isolation devices in the isolated transmission channel.

[0014] According to a preferred embodiment of the present invention, the signal transmitting module further includes an oscillator circuit, which is connected to a pulse modulation circuit and a parallel-to-serial conversion circuit respectively, for generating a clock signal to be sent to the parallel-to-serial conversion circuit and generating a high-frequency carrier wave to be sent to the pulse modulation circuit.

[0015] According to a preferred embodiment of the present invention, the signal receiving module further includes a flag signal detection circuit, which is connected after the pulse detection circuit and is used to determine the start of the serial data stream.

[0016] According to a preferred embodiment of the present invention, the serial data stream further includes a periodic flag signal, wherein the pulse generated by pulse modulation of the periodic flag signal differs from the pulse characteristics generated by pulse modulation of the serial data. Compared with the prior art, the present invention has the following advantages:

[0017] This invention employs a time-division multiplexing-based method to achieve multiple-channel transmission, utilizing only one isolation channel to transmit multiple data streams. The provided time-division multiplexing-based data modulation method improves channel utilization in digital signal isolators, reduces the area of ​​the isolation channel, lowers the cost of digital signal isolators, and simplifies circuit logic, offering a more efficient and economical solution for isolated data transmission. Attached Figure Description

[0018] Figure 1 This is an overall structural diagram of an example of the present invention.

[0019] Figure 2This is a schematic diagram of the waveforms of key nodes in the signal transmission module involved in the example described in this invention.

[0020] Figure 3 This is a schematic diagram of the starting flag signal involved in the example described in this invention.

[0021] Figure 4 These are schematic diagrams illustrating different pulse sequences involved in the examples described in this invention.

[0022] Figure 5 This is a waveform diagram of a key node of the signal receiving module involved in the example of the present invention. Detailed Implementation

[0023] The present invention will be further described and illustrated below with reference to specific embodiments. The embodiments described are merely examples of the content of this disclosure and do not limit the scope of the invention. The technical features of each embodiment in the present invention can be combined accordingly, provided that there is no mutual conflict.

[0024] Furthermore, those skilled in the art should understand that the accompanying drawings provided herein are for illustrative purposes and are not necessarily drawn to scale. It should also be understood that in the following description, "circuit" refers to a conductive loop formed by at least one element or sub-circuit through electrical or electromagnetic connections. When an element or circuit is said to be "connected" to another element or "connected" between two nodes, it can be directly coupled or connected to another element, or there may be intermediate elements; the connection between elements can be physical, logical, or a combination thereof. Conversely, when an element is said to be "directly coupled to" or "directly connected" to another element, it means that there are no intermediate elements between them. Unless the context explicitly requires it, the words "comprising," "including," and similar terms in the specification should be interpreted as encompassing rather than exclusive or exhaustive; that is, meaning "including but not limited to." In the description of this invention, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0025] In one specific embodiment of the present invention, such as Figure 1 The digital signal isolator based on time-division multiplexing for multiplexing transmission shown includes a signal transmitting module, an isolation transmission channel, and a signal receiving module. The signal transmitting module has N input ports and one output port; the signal receiving module has one input port and N output ports; there is one isolation transmission channel, with its two ends connected to the output port of the signal transmitting module and the input port of the signal receiving module, respectively; the number of input ports of the signal transmitting module and the number of output ports of the signal receiving module are equal, and their transmission relationships are one-to-one.

[0026] The signal transmission module includes a parallel-to-serial converter and a pulse modulation circuit;

[0027] The parallel-to-serial circuit described above converts multiple input parallel signals into a serial data stream;

[0028] The pulse modulation circuit modulates the high-order bits of the serial data stream into a pulse signal, and transmits the modulated signal to the signal receiving module through an isolated transmission channel.

[0029] The signal receiving module includes a pulse amplification and detection circuit, a pulse demodulation circuit, and a serial-to-parallel conversion circuit;

[0030] The pulse amplification and detection circuit amplifies and detects the signal received from the isolated transmission channel; the pulse demodulation circuit recovers the input signal from the pulse sequence amplified by the pulse amplification and detection circuit.

[0031] The serial-to-parallel conversion circuit is used to restore the serial data stream obtained by pulse demodulation by the pulse demodulation circuit into a multi-channel parallel output.

[0032] In one specific embodiment, the signal transmitting module further includes a driving circuit connected to the output of the parallel-to-serial conversion circuit and to the input of the isolated transmission channel, providing current to drive the isolation devices in the isolated transmission channel. The isolation devices in the isolated transmission channel are one or more combinations of capacitors, transformers, or light-emitting diodes.

[0033] In one specific embodiment, the signal transmitting module further includes an oscillator circuit, which is connected to a pulse modulation circuit and a parallel-to-serial conversion circuit respectively, for generating a clock signal to be sent to the parallel-to-serial conversion circuit and generating a high-frequency carrier wave to be sent to the pulse modulation circuit.

[0034] In one specific embodiment, the signal receiving module further includes a flag signal detection circuit, which is connected after the pulse detection circuit and is used to determine the start of the serial data stream.

[0035] In one specific embodiment, the signal transmitting module performs pulse encoding on the high-order bits of the serial data stream, and also performs pulse encoding on the rising or falling edge of the serial signal.

[0036] In one specific embodiment, the serial data stream further includes a periodic flag signal, the pulses generated by pulse modulation of the periodic flag signal having a different pulse characteristic than those generated by pulse modulation of the serial data. The signal receiving module uses the periodic flag signal to recover the clock and uses the recovered clock to perform serial-to-parallel conversion.

[0037] In one specific embodiment of the present invention, the transmitting module includes a parallel-to-serial conversion circuit and a pulse modulation circuit. N input signals are connected to the parallel-to-serial conversion circuit and converted into a serial data stream. A periodic flag signal is inserted at the beginning of each serial data stream. To better describe the signal modulation process, [further details are needed]. Figure 2 The waveform diagram of the key nodes of the signal transmission module shown is provided for illustration.

[0038] like Figure 2 As shown, a periodic flag signal appears at the beginning of each data stream. The flag signal, along with N input signals, passes through a parallel-to-serial converter to obtain signal (a). Signal (a) is then modulated by a pulse modulation circuit to convert the high level into a pulse with a pulse width of 1n seconds, which are signals (b) and (c). After passing through a driver, the pulse signal results in a differential signal of (d_p)-(d_n) at both ends of the isolator. The differential signal of (d_p)-(d_n) is used to distinguish the flag signal from the data signal through a first pulse sequence and a second pulse sequence.

[0039] In one specific embodiment of the present invention, different pulse sequences, such as Figure 3 As shown. A 1n pulse width signal generated during a high-level signal outputs a positive-negative pulse sequence at the isolator's terminals, called the first pulse sequence. When the signal is low, no pulses are transmitted. A periodic flag signal outputs a positive-negative-negative-positive pulse sequence at the isolator's terminals, called the second pulse sequence. The first pulse sequence differs from the second pulse sequence.

[0040] In a preferred embodiment of the present invention, the pulse transmitted from the transmitting module experiences significant amplitude attenuation after passing through the isolation channel, thus requiring pulse amplification before detection. The pulse amplification and detection circuit can detect both positive and negative pulses. The periodic flag signal can be demodulated by detecting the second pulse sequence through the pulse demodulation circuit. Simultaneously, the serial data signal can be demodulated by detecting the first pulse sequence. Then, an N-channel output is achieved through a serial-to-parallel conversion circuit. To better describe the signal modulation process, [further details are needed]. Figure 4 The waveform diagram of the key nodes of the signal receiving module is shown below. Signals (e) and (f) are the positive and negative pulse signals detected after pulse amplification. Signal (g) is the serial data stream.

[0041] Figure 5 This is a specific flag signal detection circuit implemented according to an embodiment of the present invention. The core of flag signal detection is the detection of pulse sequence; if a positive-negative-negative-positive pulse sequence appears, it is determined that a flag signal has appeared.

[0042] The operation of the digital signal isolator of this invention consists of three steps: 1) The signal transmission module of the digital signal isolator modulates multiple parallel input signals at a certain moment into a single serial data stream, and adds a flag signal bit at the beginning of each data stream. 2) The serial data stream is transmitted through a single isolated transmission channel. 3) The demodulation module of the digital signal isolator demodulates the data stream received from the isolated channel, recovers the clock by identifying the flag signal, and uses the recovered clock to demodulate the signal of each channel, thereby recovering the parallel data from the serial data stream.

[0043] In summary, this invention introduces a time-division multiplexing communication method into a digital signal isolator, modulating multiple signals into a single signal, thereby improving the utilization rate of the isolation channel, significantly reducing the area of ​​the digital signal isolator, and lowering the cost.

[0044] The embodiments described above are merely illustrative of implementation methods of the present invention. Their detailed and specific descriptions facilitate understanding and application of the invention by those skilled in the art, but should not be construed as limiting the scope of the invention. For those skilled in the art, various modifications, improvements, or alterations can be made without departing from the concept of the present invention, and these modifications all fall within the protection scope of the present invention.

Claims

1. A digital signal isolator for multiplexing based on time-division multiplexing, characterized in that, The digital signal isolator includes a signal transmitting module, an isolation transmission channel, and a signal receiving module; The signal transmission module includes a parallel-to-serial converter, a pulse modulation circuit, and a driving circuit. The parallel-to-serial circuit described above converts multiple input parallel signals into a serial data stream; The pulse modulation circuit modulates the high-order bits of the serial data stream into a pulse signal, and transmits the modulated signal to the signal receiving module through an isolated transmission channel. The driving circuit is connected to the output of the parallel-to-serial circuit and to the input of the isolated transmission channel, providing current to drive the isolation devices in the isolated transmission channel. The serial data stream also includes a periodic flag signal, wherein a flag bit is inserted at the beginning of each serial data stream; the second pulse sequence generated by the periodic flag signal after pulse modulation is different from the first pulse sequence generated by the serial data after pulse modulation; wherein the second pulse sequence is a positive-negative-negative-positive pulse sequence, and the first pulse sequence is a positive-negative pulse sequence. The signal receiving module includes a pulse amplification and detection circuit, a pulse demodulation circuit, a serial-to-parallel conversion circuit, and a flag signal detection circuit; the signal receiving module uses a periodic flag signal to recover the clock, and uses the recovered clock to perform serial-to-parallel conversion. The flag signal detection circuit is connected after the pulse amplification and detection circuit to determine the start of the serial data stream; the pulse amplification and detection circuit amplifies and detects the signal received from the isolated transmission channel; the pulse demodulation circuit recovers the input signal from the pulse sequence amplified by the pulse amplification and detection circuit; the pulse amplification and detection circuit can detect positive and negative pulses, and by detecting the second pulse sequence through the pulse demodulation circuit, the periodic flag signal can be demodulated, and by detecting the first pulse sequence, the serial data signal can be demodulated. The serial-to-parallel conversion circuit is used to restore the serial data stream obtained by pulse demodulation by the pulse demodulation circuit into a multi-channel parallel output.

2. The digital signal isolator according to claim 1, characterized in that: The isolation device in the isolated transmission channel is one or more of the following: capacitor, transformer, or light-emitting diode.

3. The digital signal isolator according to claim 1, characterized in that: The signal transmission module also includes an oscillator circuit, which is connected to a pulse modulation circuit and a parallel-to-serial conversion circuit, respectively, to generate a clock signal to be sent to the parallel-to-serial conversion circuit and to generate a high-frequency carrier wave to be sent to the pulse modulation circuit.

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