A CMOS Bandgap-Based VCSEL Driver for Temperature-Robust Optical Applications

Abstract

This paper presents a temperature-robust current-mode vertical-cavity surface-emitting laser (VCSEL) driver (or CMVD) fabricated in a standard 180 nm CMOS process. While prior art relies on conventional current-mirror circuits for bias generation, the proposed CMVD integrates a bandgap-based biasing architecture to achieve high thermal stability and process insensitivity. The bandgap core yields a temperature-compensated reference voltage and is then converted into both stable bias and modulation currents through a cascode current-mirror and switching logic. Post-layout simulations of the proposed CMVD show that the reference voltage variation remains within +/- 2%, and the bias current deviation is under 10% across full PVT conditions. Furthermore, the output current variation is limited to 7.4%, even under the worst-case corners (SS, 125 degrees C), demonstrating the reliability of the proposed architecture. The implemented chip occupies a compact core area of 0.0623 mm2 and consumes an average power of 18 mW from a single 3.3 V supply, suggesting that the bandgap-stabilized CMVD is a promising candidate for compact, power-sensitive optical systems requiring reliable and temperature-stable performance.