A Sub-Nanosecond Pulsed VCSEL Driver With PVT-Compensated Constant Current, Integrated Boost Switching Regulator and Class-1 Laser Eye Safety

This article presents a sub-nanoseconds pulsed laser diode (LD) driver IC for multi-junction (MJ-) vertical-cavity surface-emitting laser (VCSEL) arrays. An embedded real-time current control loop keeps the error of laser current amplitude within ±3% for 900 ps~32 ns pulses, even with process, voltage and temperature (PVT) variations of the VCSEL and the driver. With real-time PVT-compensation techniques, the variation of pulsewidth and propagation delay is below 140 ps for different chips under varying supply. A boost switching regulator is integrated into the IC to convert a low supply voltage into the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5\sim 8.5$ </tex-math></inline-formula>-V laser anode supply. A complete set of laser safety check blocks is integrated to guarantee class-1 eye safety, as the driver IC can stop emitting and cutoff the laser supply when a laser safety hazard is detected.