Optical coupler and manufacturing method thereof

Abstract

The invention discloses an optical coupler. The optical coupler comprises a light detection circuit composed of a light emitting diode and a phototriode. The circuit also comprises an output control circuit. The output control circuit is configured to control the output of the optical coupler according to a detection result of the optical detection circuit, the output control circuit comprises a switching-on branch circuit with a first NPN transistor and a switching-off branch circuit with a second NPN transistor, and when the optical detection circuit does not output detection current, the output of the optical coupler is set to be at a low level through the switching-on branch circuit; when the optical detection circuit outputs a detection current, the output of the optical coupler is set to a high level through the turn-off branch. The invention further discloses a manufacturing method of the optical coupler.

Description

technical field [0001] The invention relates to the field of optoelectronic devices. More specifically, it relates to an optical coupler and a manufacturing method thereof. Background technique [0002] An optocoupler, also known as an optocoupler, is a device that uses light as a medium to transmit electrical signals. Optocouplers are used in the field where isolation is required during electrical signal transmission. This isolation technology has been widely used in signal isolation transmission due to its high breakdown voltage, strong anti-interference ability and high reliability. [0003] Optocouplers can be divided into ordinary optocouplers and high-speed optocouplers in terms of the speed at which they transmit signals. Ordinary optocouplers have the best performance when the signal frequency is less than 100KHZ, and circuits with frequencies greater than 1MHZ generally use high-speed optocouplers. coupler. [0004] Ordinary optocouplers are generally composed of...

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Problems solved by technology

[0006] However, the general implementation of this high-speed optocoupler is to integrate the photodiode and the output transistor on the same substrate material. Generally speaking, the cost of this manufacturing process is much higher than the manufacturing cost of the phototransistor. Due to the limitation of manufacturing cost, in this The area of ​​the photodiode in the structure should not be too large, resulting in a weak output current capability of the photodiode. Affected by this factor, under the same load condition, the input current of the input terminal of this high-speed optocoupler is larger than that of the ordinary optocoupler. It will cause the optocoupler to increase the input power consumption of the device compared with the ordinary optocoupler

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