DATA TRANSMISSION APPARATUS, PHOTO-ELECTRIC CONVERSION CIRCUIT, AND TESTING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a data transmission apparatus in which a transmission skew between channels is reduced.

SOLUTION: The present invention relates to a data transmission apparatus which performs data communication by optical transmission, including: a transmission unit for converting telecommunication data to be transmitted into optical communication data and sending them; and a photo-electric conversion circuit for receiving the optical communication data and converting the received optical communication data into electric data. wherein the photo-electric conversion circuit includes a photo-diode for generating a current based on the optical communication data and a variable current source for subtracting a predetermined current from the current generated by the photo-diode. Furthermore, bias currents of laser diodes in the respective transmission units are set to a current greater than a laser oscillation threshold current so as to reduce variations in light emission delay times of the laser diodes.

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