Three-wire system serial communication interface isolation circuit module

Abstract

The invention discloses a three-wire system serial communication interface isolation circuit module comprising a digital power supply unit, a first level conversion unit, a second level conversion unit and a signal isolation unit, wherein the digital power supply unit comprises a non-isolated DC-DC conversion module U4 and an isolated DC-DC conversion module U5, and a power supply input end of the first level conversion unit is connected with a first digital DC power supply; the power supply input end of the second level conversion unit is connected with a second digital DC power supply; the first working power supply end of the signal isolation unit is connected with the first digital DC power supply, and a second working power supply end of the signal isolation unit is connected with the second digital DC power supply; and a data signal input end and a sending end of the first level conversion unit are respectively connected with a first serial communication interface J1, and the data signal input end and the sending end of the second level conversion unit are respectively connected with a second serial communication interface J2. The three-wire system serial communication interface isolation circuit module realizes the isolation of the serial communication interface from a hardware circuit.

Description

technical field [0001] The invention relates to a communication interface isolation circuit, in particular to a three-wire serial communication interface isolation circuit module. Background technique [0002] With the continuous development of industrial electronics, serial data communication has become an indispensable communication method for electronic equipment. The serial data communication interface (abbreviation: serial port) of the current circuit design realizes communication with the computer or other equipment. Since the reference ground planes of the two are inconsistent, when the serial port is hot-swapped or suddenly cut off / on during work, the two The discharge and surge generated between them are easy to cause damage to the equipment. Chinese Invention Patent Publication No.: CN201010551298.7 discloses a serial port isolation circuit, which adopts a transformer to realize the serial port signal isolation between the devices at both ends, and converts the RS...

AI Technical Summary

Problems solved by technology

The serial port signal isolation circuit adopts CPLD integrated selector, frequency generator, pulse inspection and latch module, etc., the cost is relatively high, the code needs to be edited, and there is a bit error rate; moreover, the conversion level between RS232 and TTL uses a transformer and a rectifier diode The structure is complicated for conversion; finally, the TxD and RxD levels of the input are both TTL levels, which is not compatible with current electronic equipment and has a narrow application range

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