CAN (control area network) bus isolated communication protective circuit

Abstract

A CAN (control area network) bus isolated communication protective circuit comprises a CAN bus input circuit, isolated output and protective circuits and a filter circuit. Bus signals of the CAN bus input circuit are connected to a signal input end of the isolated output circuit, a signal output end of the isolated output circuit is connected to an input end of the protective circuit, an output end of the protective circuit is connected to a CAN signal output end, and the CAN bus input circuit, the isolated output and protective circuits are all connected with the filter circuit. The CAN bus isolated communication protective circuit has the advantages of simple structure, effective and reliable isolation and perfect protection and can be popularized in batch.

Description

technical field [0001] The invention relates to the technical field of circuits, in particular to a CAN bus isolation communication protection circuit. Background technique [0002] CAN bus is a serial communication bus based on multi-master mode. It has obvious advantages in communication capability, reliability, flexibility, long transmission distance, etc., and has become one of the most promising field buses in the industry. CAN bus In practical applications, in order to avoid mutual influence and interference between various parts, it is necessary to isolate each part. At present, CAN bus isolation is generally carried out by means of photoelectric coupling, which realizes signal isolation through photoelectric conversion. Photoelectric conversion isolation has the following four defects: [0003] 1) The photoelectric conversion rate is effective, resulting in low transmission efficiency; [0004] 2) LEDs and phototransistors require a large driving current, so the p...

AI Technical Summary

Problems solved by technology

[0003] 1) The photoelectric conversion rate is effective, resulting in low transmission efficiency;

[0004] 2) LEDs and phototransistors require a large drive current, so the power consumption is large;

[0005] 3) The photoelectric conversion performance changes significantly with the increase of temperature, and cannot adapt to wide temperature work;

[0006] 4) The optocoupler also needs a variety of discrete components to build circuits, which is difficult to reduce in terms of cost and volume

[0007] It can be seen that photoelectric isolation cannot meet the needs of current system design in terms of cost, transmission efficiency, energy saving, reliability, and electrical characteristics of the system.

In addition, the current general CAN bus lacks a complete protection mechanism during communication, which may easily lead to CAN bus failure

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