A 15Gb/s AC-Coupled VCSEL Driver with Waveform Shaping in 65nm CMOS

A Vertical Cavity Surface Emitting Laser (VCSEL) driver in 65nm CMOS selectively-enables parallel low-power CMOS drivers to shape the output current waveforms and compensate VCSEL nonlinearities. The CMOS waveform-shaping drivers are AC-coupled allowing them to operate from a 1-V supply to save power, while parallel low-frequency paths provide programmable DC biasing from a 3-V supply. The measured VCSEL driver is able to achieve 15Gb/s with up to 5.1dBm OMA at a total power dissipation of 60mW, or 2.1dBm OMA at 28mW corresponding to 1.9pJ/bit. The driver occupies 250 × 160μm including the on-die AC-coupling.