CN-117134837-B - Digital signal isolator for realizing multiplexing based on time division multiplexing

CN117134837BCN 117134837 BCN117134837 BCN 117134837BCN-117134837-B

Abstract

The invention discloses a digital signal isolator for realizing multiplexing based on time division multiplexing. The digital signal isolator comprises a signal transmitting module, an isolating channel and a signal receiving module. The signal transmitting module of the digital signal isolator periodically samples and modulates the multipath parallel input signals into one path of serial data stream, and a flag signal bit is added at the beginning of each data stream. And transmitting the serial data stream from the signal transmitting module to the signal receiving module by using one path of isolation channel. The receiving module of the digital signal isolator demodulates the data stream received from the isolated channel, recovers the clock through the initial mark signal, demodulates the signal of each path by using the recovered clock, and further recovers the parallel data from the serial data stream. The invention has the advantages that the invention modulates the multipath signals into one path of signal transmission through modulation, thereby improving the utilization rate of the isolation channel and reducing the cost.

Inventors

QU WANYUAN
DING YI

Assignees

浙江大学

Dates

Publication Date: 20260508
Application Date: 20230817

Claims (3)

1. The digital signal isolator is characterized by comprising a signal transmitting module, an isolated transmission channel and a signal receiving module; The signal transmitting module comprises a parallel-to-serial circuit, a pulse modulation circuit and a driving circuit; the parallel-to-serial circuit converts the input multipath parallel signals into serial data streams; the pulse modulation circuit modulates high bits in the serial data stream into pulse signals, and transmits the modulated signals to the signal receiving module through the isolated transmission channel; the driving circuit is connected with the output of the parallel-to-serial circuit and the input of the isolation transmission channel, and provides current for driving the isolation device in the isolation transmission channel; The serial data stream also comprises a periodic mark signal, wherein the periodic mark signal inserts a mark bit at the beginning of each serial data stream, and a second pulse sequence generated by the periodic mark signal after pulse modulation is different from a first pulse sequence generated by the serial data after pulse modulation, wherein the second pulse sequence is a positive-negative-positive pulse sequence, and the first pulse sequence is a positive-negative pulse sequence; The signal receiving module comprises a pulse amplification detection circuit, a pulse demodulation circuit, a serial-to-parallel circuit and a mark signal detection circuit, wherein the signal receiving module recovers a clock by using a periodic mark signal and performs serial-to-parallel conversion by using the recovered clock; The signal detection circuit is connected with the pulse amplification detection circuit and is used for judging the start of the serial data stream, the pulse amplification detection circuit amplifies and detects the signal received from the isolation transmission channel, the pulse demodulation circuit recovers the input signal from the pulse sequence amplified by the pulse amplification detection circuit, the pulse amplification detection circuit can detect positive and negative pulses, the periodic signal can be obtained by detecting the second pulse sequence through the pulse demodulation circuit, and the serial data signal can be obtained by demodulating the first pulse sequence; The serial-to-parallel circuit is used for recovering the serial data stream obtained by pulse demodulation of the pulse demodulation circuit into multiple paths of parallel output.
2. The digital signal isolator of claim 1, wherein the isolation device in the isolated transmission channel is one or a combination of a capacitor, a transformer, or a light emitting diode.
3. The digital signal isolator of claim 1, wherein the signal transmitting module further comprises an oscillator circuit, and the oscillator circuit is respectively connected with the pulse modulation circuit and the parallel-to-serial circuit and is used for generating a clock and transmitting the clock to the parallel-to-serial circuit, and generating a high-frequency carrier and transmitting the high-frequency carrier to the pulse modulation circuit.

Description

Digital signal isolator for realizing multiplexing based on time division multiplexing Technical Field The invention relates to a communication technology and a digital isolation technology, in particular to a digital signal isolator for realizing multiplexing based on time division multiplexing. Background Time division multiplexing is a multiplexing mode in the field of communication, in which different signals are put in different time periods and transmitted along a transmission path. At the signal receiving end, the signals in different time periods are extracted again, so that the multipath signals are transmitted on the same channel. Digital signal isolators are widely used in the fields of automotive electronics, medical electronics, industrial manufacturing, etc. for transmitting data between two devices that are not electrically connected. The important characteristics of the isolator are to protect the safety of human body and equipment and to isolate noise. The current mainstream isolation mode is three, namely optical coupling isolation, capacitance isolation and magnetic isolation. Different isolation modes have different advantages and disadvantages, and are required to be selected according to application scenes and requirements. The current modulation modes commonly used for isolated communication comprise OOK modulation, pulse modulation and the like. In a conventional digital signal isolator, one data channel occupies one isolation channel, and each path of data is independently modulated and demodulated, so that one set of isolation channels needs to be added for each path of signal transmission. This results in an increased isolation channel area and a bulky overall isolator. Disclosure of Invention The invention aims at providing a digital signal isolator for realizing multiplexing based on time division multiplexing, the invention introduces a communication method of time division multiplexing into the digital signal isolator, the multipath signals are modulated into one path of signals, so that the utilization rate of the isolation channel is improved, the area of the digital signal isolator is obviously reduced, and the cost is reduced. Through the innovation, on the premise of keeping the signal isolation performance, the design of the compact and efficient digital signal isolator can be realized, and the application requirements of different fields are further met. In order to achieve the purpose, the invention provides the following technical scheme: The invention provides a digital signal isolator for realizing multiplexing based on time division multiplexing, which comprises a signal transmitting module, an isolated transmission channel and a signal receiving module; the signal transmitting module comprises a parallel-to-serial circuit and a pulse modulation circuit; the parallel-to-serial circuit converts the input multipath parallel signals into serial data streams; the pulse modulation circuit modulates high bits in the serial data stream into pulse signals, and transmits the modulated signals to the signal receiving module through the isolated transmission channel; the signal receiving module comprises a pulse amplification detection circuit, a pulse demodulation circuit and a serial-to-parallel circuit; The pulse amplification detection circuit amplifies and detects signals received from the isolated transmission channel; the pulse demodulation circuit recovers an input signal from the pulse sequence amplified by the pulse amplification detection circuit; The serial-to-parallel circuit is used for recovering the serial data stream obtained by pulse demodulation of the pulse demodulation circuit into multiple paths of parallel output. According to a preferred embodiment of the invention, the signal transmitting module further comprises a driving circuit connected to the output of the parallel to serial circuit and to the input of the isolated transmission channel for supplying current to the isolated devices in the isolated transmission channel. According to a preferred embodiment of the present invention, the signal transmitting module further includes an oscillator circuit, and the oscillator circuit is respectively connected to the pulse modulation circuit and the parallel-to-serial circuit, and is used for generating a clock and transmitting the clock to the parallel-to-serial circuit, and generating a high-frequency carrier and transmitting the high-frequency carrier to the pulse modulation circuit. According to a preferred embodiment of the present invention, the signal receiving module further comprises a flag signal detecting circuit connected after the pulse detecting circuit for judging the start of the serial data stream. According to a preferred embodiment of the present invention, the serial data stream further comprises a periodic flag signal, wherein the pulse generated by the periodic flag signal after pulse modulation is different from the pulse characteris