Asynchronous 250-mb/s optical receivers with integrated detector in standard CMOS technology for optocoupler applications

A high-speed ten-channel optical receiver, integrated in a standard 0.6-mu m CMOS technology, is presented. Each data channel consists of a spatially modulated light detector (SML-detector) and a low-offset receiver. The SML-detector has a much higher intrinsic bandwidth than a conventional photo-diode junction implemented in standard CMOS. One channel of the ten is sacrificed and used as a reference to define the threshold level for the other channels. The optical receiver can handle up to 250 Mb/s of noncoded data (including de) per channel at 20 mu W average light input power (lambda = 860 nm). Power dissipation per channel is only 4 mW. When combined with appropriate light emitters, a compact and low-cost optocoupler can be obtained with improved speed performance compared to existing optocouplers.