Simulation And Design Of High Speed Optical Coupler Circuits

Optical Coupler is made up of light emitting diode and photo-electronic triode. Its small cubage, longevity, non-contact, anti-interference, isolation, and unidirectional signal transmission lead to its widely spread in varieties of opto-electronics system and control system. Firstly, an overview to the component, the parameter and the importance of Optical Coupler are given. The irradiating principle of infrared light emitting diode and the working theory of photodiode are highlighted.A high precision isolation circuit design based on a linear Optical Coupler HCNR201 is proposed. This designed circuit concludes two parts: high precision voltage measurement circuit and switching regulator circuit. High precision voltage measurement circuit is divided as follows: the input part, isolation part and output part. The main circuit is based on the structure of the simplified compensation with single Optical Coupler, and the DC constant current source and power supply are designed at the same time. When calculating the expression of DC signal transmission, an important conclusion is gotten: the feedback structure eliminates the influence of the current transmission ratio of the Optical Coupler. Using linear method to calculate the transfer function in the frequency domain, circuit design principle diagram are respectively drew and simulated at Mutlism10.0. At the same time hardware circuits are also drew out at Altium designer 6.0. Data processing software uses MATLAB7.0. The results show that the signal isolating instruments have good isolation effect. At the same time, in the application of Optical Coupler, a high speed Optical Coupler is been designed together with my classmates through reverse analysis of a certain type of Optical Coupler.