| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical transmission circuit, an optical reception circuit and an optically coupled isolation circuit, capable of facilitating test of an optical coupling unit. <P>SOLUTION: The optically coupled isolation circuit includes: an optical transmission circuit having an analog-digital conversion circuit which converts an analog signal into a digital signal, an encoding circuit which superimposes the output from the analog-digital conversion circuit on a signal based on the clock and generates a transmission signal which is encoded to have an average duty ratio greater than 0 but less than 1, a transmission control circuit which outputs the transmission signal or the analog signal depending on the input level of the analog signal, and an electro-optical conversion device which converts the output from the transmission control circuit into an optical signal and outputs the converted optical signal; and an optical reception circuit having a photoelectric conversion circuit which receives the optical signal and converts the received optical signal into an electric signal, a decoding circuit which decodes the output from the photoelectric conversion circuit and outputs a reproduction digital signal and a reproduction clock, and a reception control circuit which delivers the output from the decoding circuit or the output from the photoelectric conversion circuit depending on the average duty ratio of the output from the photoelectric conversion circuit. <P>COPYRIGHT: (C)2011,JPO&INPIT |
