The FIS121NL is a current sense inductor that serves as a feedback element linking the output and pulse control circuitry in power supplies. It features a primary-to-secondary turns ratio of 1/200, a minimum secondary inductance of 94.5 mH, and a maximum secondary DC resistance of 4.50 Ω. This inductor is rated for a maximum primary current of 15 A and provides 2500 Vac of isolation between the primary and secondary windings. Designed for a maximum frequency of 200 kHz and an operating temperature range of -40°C to +125°C, the FIS121NL is a reliable component for current regulation applications.