Isolated communication circuit

Abstract

The invention discloses an isolated communication circuit comprising two optoelectronic couplers, two optocoupler drive modules, and two data drive modules. The optocoupler drive modules are gate circuits enabled by high levels; and the data drive modules are gate circuits with open-drain outputs. According to the invention, reliable isolation of circuit systems of the two parties in communication can be realized; and the provided circuit can be constructed and completed by using several kinds of common electronic elements, thereby effectively lowering the realization cost of the bidirectional isolation communication. Furthermore, optoelectronic couplers, with different specifications are selected for usage and thus the creepage distance between the circuits of the two parties in communication can be adjusted flexibly, so that the isolated communication circuit has the wide application range.

Description

technical field [0001] The invention relates to the technical field of data communication, in particular to an isolated communication circuit. Background technique [0002] In a diversified control system, different control units need to communicate with each other. These different control units often work in their own independent and isolated power systems without direct electrical connection between them. Therefore, how to realize the isolation of the data communication bus between the various control units in the mutually isolated power supply system has become a very critical issue in many application scenarios. [0003] According to the existing technology, there are two main ways to realize the communication between different control units in the mutually isolated power supply system: one is electromagnetic isolation, and the other is photoelectric isolation. The transmission of signals is realized in the case of connection, but there are also their own defects: the e...

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Problems solved by technology

[0003] According to the prior art, there are mainly two ways to realize the communication between different control units in the mutually isolated power supply system: one is electromagnetic isolation, and the other is photoelectric isolation. In the case of connection, the transmission of signals is realized, but there are also their own defects: the electromagnetic isolation method requires more complicated technology and process, which is not conducive to cost control, and is prone to EMC (electromagnetic compatibility) problems; although the photoelectric isolation method is realized Relatively simple, but commonly used optocouplers can only isolate unidirectional signals, and can be used for unidirectional communication isolation

However, this type of chip is not only expensive, but also based on electromagnetic technology, it is still easy to cause EMC problems, and due to the size of the chip, it cannot meet the creepage distance requirements in some cases

Therefore, it is not suitable for many applications

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