TISP4040H1BJR-S is a very low voltage bidirectional thyristor overvoltage protector designed for digital line signal level protection in ISDN and xDSL applications. The device features a symmetrical voltage-triggered thyristor architecture with a repetitive peak off-state voltage (VDRM) of ±25 V and a breakover voltage (V(BO)) of ±40 V, providing robust protection against transient overvoltages. It exhibits low capacitance of 59 pF at 1 MHz, minimizing signal distortion in high-frequency circuits, and operates with a maximum on-state voltage of ±3 V and holding current of ±50 mA. The device is packaged in SMB (DO-214AA) format, RoHS compliant, and rated for 100 A surge current per ITU-T recommendations K.20, K.45, and K.21, making it ideal for transformer winding protection and low-voltage electronics in telecommunications and data communication systems.