Optical modules and methods of making the optical modules

摘要

A sample & hold type phase detector is used in a CDR IC and, in jitter transfer bandwidth adjustment, VCO output waveforms 90° out of phase with each other can be inputted to the phase detector, whereby a jitter transfer bandwidth can be calculated by only the measurement of frequency and of a DC voltage and it is possible to make a jitter transfer bandwidth adjustment in DC test for IC.