Obsolete — last-time-buy sourcing
Littelfuse has marked the 1206SFS500F/32-2 as obsolete.
5 A slow-blow — what the ratings mean for fit
Rated 5 A continuous at 32 V DC, this is a board-mount slow-blow fuse in the 1206 (3216 metric) package. The slow-blow response means it tolerates brief inrush current spikes — think capacitive loads on a power input or motor start — without nuisance opening, while still clearing sustained overcurrents. The 50 A breaking capacity at rated voltage is the maximum fault current it can safely interrupt. In a 32 V DC circuit, that covers most secondary-side power rails in telecom, industrial control, and automotive auxiliary loads — but not a direct battery-line fault where available short-circuit current exceeds 50 A. Melting I²t of 5.3 quantifies the energy needed to open the fuse element. This is the number you compare against the I²t of the downstream components (diode, FET, capacitor) to ensure the fuse clears before they fail short.
Surface-mount deployment and temperature range
DC cold resistance is 0.016 Ω — negligible voltage drop at rated current (80 mV at 5 A), but the resistance rises as the element heats under load, so derate for ambient temperature. The UL recognition means it has passed UL 248-14 testing for branch-circuit protection — a common requirement in North American industrial equipment.