A 25Gb/s Common-Cathode VCSEL Driver

A common-cathode VCSEL driver is presented in this paper. Overcoming the large parasitics introduced by the current source at the output node, this VCSEL driver is able to operate at data rate of 25Gb/s. With different rising/falling edge speed, it is able to address the non-linear issues of VCSEL diode. The VCSEL driver was fabricated using IBM8HP BiCMOS technology, dissipating less than 60mW and featuring a core area of 0.45mmX200mm.