3 A fast-blow fuse for 63 V DC rails
The F1206B3R00FWTR is a 3 A fast-blow surface-mount fuse from the KYOCERA AVX Accu-Guard® II series, rated for 63 V DC and housed in a 1206 (3216 metric) package. Its 50 A breaking capacity at rated voltage means it can safely interrupt a short-circuit fault up to 50 A without sustaining an arc — a key parameter for DC power rail protection in industrial and telecom equipment. With a DC cold resistance of 0.05 Ohms, the voltage drop at rated current is about 150 mV, which is negligible for most 5 V or 12 V rails but worth checking on a 3.3 V supply where every millivolt of headroom matters.
Melting I²t and response time
The melting I²t of 0.1 A²s tells the fuse will open quickly on a high overcurrent — the fast-blow characteristic suits loads with minimal inrush, such as sensor modules, logic power inputs, or DC-DC converter input protection. If your circuit has a capacitive input filter that draws a surge at power-up, compare the I²t of the surge against this 0.1 A²s value; a fast-blow fuse may nuisance-open on that inrush, and a slow-blow alternative would be a better fit.
CT suits prototype or low-volume builds.
Temperature range and approvals
It carries cUL and UL approval, which simplifies compliance for equipment sold into North American markets.