TBU-RS085-300-WH is an integrated dual channel Transient Blocking Unit (TBU) overcurrent device with TVS overvoltage protector designed for RS-485 communications interface protection. It features a peak impulse voltage withstand of 850 V, continuous AC RMS voltage rating of 425 V, and a fast protection response time of 1 µs. The device has a trigger current range of 300-600 mA, on-resistance of 15-26 O, and operates over a temperature range of -55°C to +125°C. When coupled with external overvoltage protectors like GDTs or thyristors, it aids compliance to IEC 61000-4-2 (ESD), IEC 61000-4-4 (EFT), and IEC 61000-4-5 (Surge) standards up to Class 4 protection levels. The device is available in a DFN package and is ideal for RS-485 interface surge protection and AISG modem protection applications.