Digital isolator and transmitting circuit thereof

Abstract

The invention discloses a digital isolator and a transmitting circuit thereof, and the transmitting circuit comprises a digital transmitter, a high-side selection circuit and a low-side selection circuit. The high-side selection circuit selects and outputs a digital signal to the power supply end of the digital transmitter, and the low-side selection circuit selects and outputs a common ground signal to the grounding end of the digital transmitter; the high-side selection circuit comprises a high-side control circuit, a first high-side branch and a second high-side branch, wherein the first high-side branch and the second high-side branch are used for receiving digital signals and common ground signals respectively. The output end of the high-side control circuit is connected with the power supply end, the control end of the high-side control circuit is connected with the first high-side branch and the second high-side branch, and the high-side control circuit is configured to control the conduction degree of the first high-side branch or the second high-side branch to be constant according to the digital signal and the common ground signal. The transmitting circuit provided by the invention can adapt to the working environment of bidirectional high-voltage signal input, can keep the working and heating power of the circuit stable, unifies the multi-channel ground level, and reduces the circuit cost.

Description

technical field [0001] The present invention relates to the technical field of isolation, in particular to a digital isolator and a transmission circuit thereof. Background technique [0002] Digital isolators, or digital isolation units or digital isolation chips, are usually used to ensure the normal transmission of signals between two systems in an industrial factory environment. In a specific case, it can be used to receive digital inputs from switches and sensors, and output them to the back end after processing and isolation. In this process, the situation of the above digital input, especially the input direction and voltage level, is difficult to grasp and control on the side of the digital isolator, which will lead to the loss of the reverse digital input signal, increase the packaging cost, and it is difficult to adapt to more High voltage input requirements, as well as the problems of system power accumulation and large heating power. [0003] In the prior art, ...

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Problems solved by technology

[0004] One of the purposes of the present invention is to provide a digital isolator transmission circuit to solve the technical problems that the digital isolation circuit in the prior art is difficult to adapt to the bidirectional high-voltage input environment, the working and heating power is large, and the overall cost of the circuit is high.

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