Symmetric and asymmetric isolation type driving signal transmission circuit

Abstract

The invention provides a symmetric and asymmetric isolation type driving signal transmission circuit. The symmetric and asymmetric isolation type driving signal transmission circuit comprises an inputcircuit, an isolator and an output circuit, the isolator isolates the power supply and the ground of the output circuit from the power supply and the ground of the output circuit; the input line generates symmetric or asymmetric modulation signals to the isolation medium after voltage transference wave modulation according to the level condition of input signals. The output line receives the modulation signal passing through the isolation medium, and generates an output signal after carrier-to-voltage demodulation. According to the symmetric and asymmetric isolation type driving signal transmission circuit, compared with conventional 2FSK modulation, the input line part is modulated by voltage transference waves, the requirement for carrier signals is low, modulation and demodulation of driving signals are not affected when carrier frequency and asymmetry fluctuation is not large, the circuit design difficulty is lowered, and the product robustness is improved.

Description

technical field [0001] The invention relates to an isolation circuit, in particular to an isolation driving signal transmission circuit. Background technique [0002] The main function of isolation is to separate one line from another line to avoid interference, such as using an insulator (dielectric) to separate the two lines. It can also be said to isolate two different voltage domains. For example, in a control system, the processor power supply is usually a low-voltage 5V, and the load power supply is usually a high-voltage 220V. If the two voltage domains are not isolated, the operation of the high-voltage domain will affect the low-voltage domain. Cause serious interference, and even damage devices in the low-voltage domain. If digital signals can be transmitted while being isolated, it is usually through a high-frequency carrier. Such media that can both isolate high voltage and transmit signals include inductors, transformers, optocouplers, capacitors, NVE magnetic...

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Problems solved by technology

It can also be said to isolate two different voltage domains. For example, in a control system, the processor power supply is usually a low-voltage 5V, and the load power supply is usually a high-voltage 220V. If the two voltage domains are not isolated, the operation of the high-voltage domain will affect the low-voltage domain. Cause serious interference and even damage devices in the low-voltage domain

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