ATOP 50G QSFP28 PAM4 module is designed for 50G Ethernet links over 40km single mode fiber with a single power supply of 3.3V and power dissipation < 4.5W, supporting 2×26.5625Gbps electrical interface. Digital diagnostics functions are available via an I2C interface, as specified by the QSFP MSA and fully compliant with RoHS-6 (lead free).