3.3 V, 5O Mb/s CMOS transceiver for optical burst-mode communication

An instantaneous-response CMOS amplifier uses feed-forward. As the LD driver can be realized with CMOS technology more easily than the amplifier, both the AGC amplifier and the LD driver can be integrated in a chip. A 0.8/spl mu/m CMOS process for mass production reduces chip cost. To further reduce cost, it is important to shorten the adjustment time by decreasing the number of circuits requiring adjustment. Conventionally, more than four adjustments are necessary: offset canceling, reference level setting for AGC and comparator and optical output level setting. This problem can be solved by using a CMOS adjustment-free amplifier. The operating margin against process variation is increased by multistage automatic offset canceling (AOC). AOC reduces test time and makes 3.3V operation possible because of the large operation margin.