3.125 Gb/s temperature compensated CMOS optical preamplifier with automatic gain control

This paper presents a low-voltage variable preamplifier with automatic gain control, which works at 3.125 Gb/s in the optical standard 10Gbase-LX4. The system incorporates a circuit that minimizes the temperature effects. The preamplifier achieves adaptive transresistance, 60-74 dBOmega, with an almost constant bandwidth, 2.2 GHz, and with no peaks in the frequency response. The circuit was designed in 0.18 mum CMOS technology with a single 1.8 V supply voltage.