Sensitive-gate SCR for low-drive applications
The STMicroelectronics X0115MUF is a sensitive-gate SCR rated for 1 A RMS on-state current and 600 V off-state blocking, housed in a 3-SMB flat-lead surface-mount package (SMBflat-3L). The 150 µA maximum gate trigger current (Igt) means a low-current signal — from a microcontroller GPIO, a comparator output, or a Hall-effect sensor — can fire the SCR directly without a driver transistor or buffer stage.
1 A RMS / 600 V — sizing the load and the isolation
The 1 A RMS on-state current (It(RMS)) and 640 mA average (It(AV)) define the continuous load this SCR can handle. For a resistive load like a heater or incandescent lamp, the 1 A RMS rating gives headroom for inrush at turn-on. The 600 V off-state voltage (Vdrm/Vrrm) means it blocks mains peaks cleanly in 120 VAC or 277 VAC systems, and with margin for 240 VAC line transients. The 1.4 V maximum on-state voltage (Vtm) at rated current is typical for a 1 A SCR — the conduction loss is about 1.4 W at full load, so the SMBflat-3L package's thermal path to the PCB copper matters for continuous duty above 500 mA.
Active lifecycle, no obsolescence clock
ROHS3 compliance is confirmed.
Package and footprint — SMBflat-3L
The 3-SMB flat-lead package (SMBflat-3L) is a low-profile surface-mount alternative to through-hole SCRs in TO-92 or DPAK. The flat leads sit flush with the PCB, which helps with automated optical inspection and reduces tombstoning risk during reflow.