BT139-800E is a Thyristor series manufactured by NXP. It is an ultra-fast, symmetrical and sensitive gate silicon controlled rectifier (SCR) specially designed for power switching applications in low-voltage systems up to 800 V. These devices can handle an average on-state current (Iav) of up to 13 A and have a non-repetitive peak on-state current (Ip) up to 50 A. These SCRs are designed to provide excellent thermal shock, conducted emissions and dv/dt noise immunity and have a high surge current capability that extends their lifetime. They include an integrated protection function which limits the anode current to a safe level in the event of a reverse voltage transient. These features make these SCRs well-suited for a variety of applications, such as AC and DC motor control, battery charger, inverter and phase control applications.