A 10 Gb/s, 150 mA Laser Diode Driver with Active Back-Termination in 0.13-µm SOI CMOS Technology

The design of a 10 Gb/s laser diode driver (LDD) in 0.13-μm SOI CMOS technology is described. The driver utilizes cross-coupled neutralization capacitors and integrates a tunable negative capacitance circuit to extend the bandwidth. Loading reflections due to the imperfect matching at the laser side are absorbed by an active back termination (ABT) circuit. Compared to a driver with a resistive termination, the proposed driver reduces the power dissipation by 40%. The LDD can deliver a modulation current ranges from 10 to 150 mA to 25-Ω lasers with a preserved dynamic performance due to the usage of a segmented output driver scheme. Post-layout simulation results show that the proposed driver has a bandwidth of 7 GHz, and the return loss is better than 8.6 dB in the frequency band of interest. The driver supports DC and AC coupling to 25-Ω lasers with a total power dissipation of 1.06 and 0.72 W, respectively at maximum output current. The physical layout occupies an area of 0.84 × 0.9 mm
²
.