The LT1680CSW#PBF is a current-mode PWM controller from Analog Devices built for boost and forward converter topologies. It drives an external transistor switch — no synchronous rectifier on-chip — and handles a supply rail from 9V to 60V. The 90% maximum duty cycle gives headroom for high step-up ratios in boost stages. Output is a single positive rail, controlled via enable and soft-start pins.
That means this part belongs in a controlled indoor environment: bench supplies, server PSUs, telecom racks with forced air, or lab equipment. Not the part you spec for an engine bay or a rooftop radio without derating or active cooling. Storage temperature exceeds the operating range, but the running limit is what governs the thermal design.
Supplied in a tube, 16-SOIC wide-body (7.50 mm width). The 0.295" body width is the wider SOIC variant — verify the PCB footprint matches the wide-body land pattern, not the narrow SOIC.