Design of a 622Mb/s 16-channel CMOS optical transceiver array

Abstract

We describe design of 622 Mb/s 16-channel CMOS optical transceiver array using the 0.35 micrometers CMOS technology. The transceiver array consists of Laser Diode (LD) driver and limiting amplifier with trans-impedance amplifier. CMOS LD driver offers the capability of independent dc and modulation current adjustments. The dc circuit used to pre- bias LD is adjustable for the dc current at a range of 0~30 mA. Because each amplifier block is dc-coupled, there are several sources of nonlinearity in the amplifier chains. These problems deteriorate the magnitude and timing performance. In order to solve these problems, we employ a compensate circuit which consists of positive and negative peak detectors and decision comparator. This scheme forces the data to be sliced in the middle eliminating timing errors. With this design technique, we have succeeded in developing a CMOS optical transceiver array with a high performance.