The final design and results of the ADDAPT VCSEL driver has been accepted for publication in IEEE Journal of Solid-State Circuits. Each lane of the 4-channel TX includes a two-tap feed-forward equalizer and achieves a data rate of 45 Gb/s. It is equipped with rapid-on/off switching capability for burst-mode operation and performance adaptivity. The TX saves 86 % of power in standby mode and can be switched-on in below 10 ns. The total power dissipation at full speed is below 100 mW, providing an energy efficiency of better than 2.11 pJ/bit.