Current/Voltage Mode VCSEL Drivers with Tunable Pre-emphasis for Large Temperature Range

Paper in proceeding, 2025

We present two NRZ VCSEL (vertical-cavity surface-emitting laser) driver circuits, designed for extended temperature range. The drivers operate in current and voltage mode, with 3-tap analog-controlled continuous-time linear equalizer (CTLE) pre-emphasis. The two designs offer different trade-offs in terms of bandwidth and thermal performance. Open electrical eyes are shown at 50 Gbps and 40 Gbps respectively for voltage-mode and current-mode drivers, across an extended temperature range from 25 °C to 125 °C. The energy efficiency at 125 °C at 40 Gbps is 5.03pJ/b for the current-mode and 6.48pJ/b at 50 Gbps for the voltage-mode driver.