The TN1215-800H is a type of SCR (Silicon Controlled Rectifier) manufactured by STMicroelectronics. It is a standard 12A SCR rated for an on-state current of 12A and an off-state voltage of 800V. It features a four-terminal design with a highly efficient control gate design for energy savings and reliability. It comes in a TO-220 package with a lead frame for increased heat dissipation. The TN1215-800H provides a high degree of circuit protection and reliability, making it well suited for use in high power applications, such as motor control, power switching, motor speed control, DC-DC converters, and rectifier circuits.