Protection envelope and board-fit note
The Littelfuse 0603SFV350F/32-2 is a 3.5 A, 32 VDC fast-blow board mount fuse in the SFV series, housed in a 0603 (1608 Metric) surface-mount package. Its 35 A breaking capacity at rated voltage means it can safely interrupt a fault current up to that level without rupturing the package — critical for secondary-side protection in DC power rails where the available fault current stays below that ceiling.
Energy let-through and coordination
With a melting I²t of 0.73 A²s, this fuse lets through a defined amount of energy before opening. Downstream components — traces, connectors, semiconductors — must survive that pulse without damage; the I²t value feeds directly into the coordination math for a DC supply rail. The DC cold resistance of 0.028 Ohms sets the voltage drop at rated current at roughly 98 mV — negligible in a 32 V rail, but worth confirming against the minimum operating voltage of the load at the end of the trace.
The UL approval certifies the safety compliance for the rated interrupting capacity — a requirement for passing the end-equipment safety certification in most jurisdictions.
Lifecycle reality and sourcing posture
Littelfuse has marked the 0603SFV350F/32-2 as obsolete.