| 摘要 |
<p>PURPOSE:To largely reduce the clock skew and to increase the frequency of a clock signal by providing the system with a window part on the upper part of a package to transmit the light and generating the clock signal to be supplied to an internal circuit through a photodetecting element in response to the optical pulse received from a light source. CONSTITUTION:A window part 7 is provided on the upper surface part of a package 6 and at a part corresponded to a digital IC chip which is sealed inside the package 6, and a clock signal generation control part 8 is provided so as to face the upper part of the part 7. The part 8 is provided for the light sources 1-a and 1-b which emit the light of different wavelengths. Then, an optical pulse which is synchronous with the clock signal is generated by a drive pulse corresponding to the clock signal supplied to the part 8. The photodetecting elements 2-a and 2-b react to the light of the light sources 1-a and 1-b respectively and perform the switching operations for the optical pulses of different wavelengths generated by both light sources 1-a and 1-b, and generate the clock signals which are supplied to an internal circuit.</p> |
