Low-cost analog linear optocoupler

Abstract

The invention discloses a low-cost analog linear optocoupler, which includes a first operational amplifier (IC1), a second operational amplifier (IC4), a first optocoupler (IC2), a second optocoupler (IC3), a first resistor (R1), a second resistor (R2), a third resistor (R3), a capacitor (C1), a primary side power source (VDD), a primary side area (GND), a secondary side power source (VCC), a secondary side area (GND2), a positive input end (VIN) and a positive output end (Vout), wherein light emitting diodes of the two optocouplers are connected in series, so that electric currents flowing through the two light emitting diodes are consistent, isolation feedback is realized, a circuit is enabled to work steadily, complete electric isolation between the primary side and the secondary side is realized, systems on two sides can be isolated on the premise that transmission of analog signals is realized, and influences are avoided. Meanwhile, the circuit has ideal output impedance, so that the treatment of a rear connection system is facilitated. The low-cost analog linear optocoupler is simple in structure and connection, is low in cost, can replace expensive linear optocouplers to realize isolation transmission of the analog signals.

Description

technical field [0001] The invention belongs to the field of analog signal isolation transmission and relates to an analog linear optocoupler circuit. Background technique [0002] In many industrial site signal acquisition systems and control systems, it is necessary to collect and know the analog signals of the industrial site, and the collected signals work in harsh environments, often accompanied by extremely high common-mode interference and spike signals. If these common-mode interferences are introduced In the post-processing system, the system will often fail to work or even be damaged, which will cause production accidents on the industrial site. Therefore, the isolation and transmission of analog signals plays an extremely important role in many circuit systems. [0003] The currently known solution is to use a linear optocoupler, but the linear optocoupler is expensive, which will increase the cost of the system, and the output of the linear optocoupler is a diff...

AI Technical Summary

Problems solved by technology

[0003] The currently known solution is to use a linear optocoupler, but the linear optocoupler is expensive, which will increase the cost of the system, and the output of the linear optocoupler is a differential signal

An instrumentation amplifier is required to convert the differential signal to a common-mode single-ended signal, making the system more complex and expensive

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