The STMicroelectronics Z0107SN 5AA4 is a logic-level sensitive-gate triac rated for 700 V off-state and 1 A RMS on-state current, housed in a surface-mount SOT-223 package. It is designed for low-power AC switching applications where a microcontroller or logic gate drives the gate directly — the 5 mA maximum gate trigger current keeps the drive circuit simple, no extra transistor stage needed. Typical uses include solid-state relays, small motor controls, lighting dimmers, and valve actuators in industrial and appliance environments.
The Z0107 base number is a long-running ST product, so supply continuity is solid.