600 V sensitive-gate SCR for low-power AC/DC switching
The STMicroelectronics X00619MA1AA2 is a sensitive-gate silicon controlled rectifier (SCR) in a TO-92-3 through-hole package, rated for 600 V off-state voltage and 800 mA RMS on-state current. The 200 µA maximum gate trigger current (Igt) classifies it as a sensitive-gate device, meaning a low-power signal from a microcontroller or logic gate can fire it without an intermediate driver transistor.
With an average on-state current of 500 mA and an RMS rating of 800 mA, this SCR is sized for loads like small solenoids, indicator lamps, or low-power heating elements. The non-repetitive surge current of 9 A at 50 Hz and 10 A at 60 Hz gives a reasonable margin for capacitor inrush or brief fault events — enough for many appliance and industrial control boards, but not a heavy motor-drive application. The maximum on-state voltage of 1.35 V at rated current means you should budget roughly 1.5 V drop across the device when calculating the minimum supply voltage for the load.
Holding current and off-state leakage
The maximum holding current (Ih) is 5 mA, which sets the minimum load current needed to keep the SCR latched once triggered. Below that level the device will drop out of conduction — useful for self-resetting circuits, but worth checking if the load current varies or is pulsed. Off-state leakage is specified at a maximum 1 µA, which is low enough to avoid wasting power in standby or when the SCR is blocking the line.
The TO-92-3 package is a standard three-lead through-hole footprint.