1.25 A fast-blow in 1206 — Accu-Guard® F1206A1R25FWTR
The F1206A1R25FWTR is a 1.25 A fast-blow surface-mount fuse from the KYOCERA AVX Accu-Guard® series, housed in a standard 1206 (3216 metric) package. It is rated for 32 VDC and can interrupt fault currents up to 50 A at that voltage, which covers most low-voltage DC rail protection needs in telecom, industrial control, and consumer electronics. The melting I²t of 0.009 is the energy required to open the fuse — a low value that means it responds quickly to short-duration overcurrents, making it suitable for protecting sensitive circuits where fast clearing is needed.
DC cold resistance and operating range
DC cold resistance is 0.15 Ohms, which sets the voltage drop and self-heating under normal load. At 1.25 A, the I²R loss is about 0.23 W — negligible for most boards, but worth checking if the fuse sits in a high-ambient or tightly packed area.