An EPCOS gas-filled surge arrester, which consists of a stack of five individual arresters, offers reliable quenching of an applied dc voltage. It has a rated dc operating voltage of 48 V dc plus 20%, according to IEC 61643-11. Surge current capability measures 20 kA at an impulse wave of 8/20 µs, and 4 kA at an impulse wave of 10/350 µs. The arrester, developed by TDK Corp., corresponds to a climate category of 40/90/21 of IEC 600068-1, and operates from -40 to +90°C. Thanks to a capacitance of less than 1 pF (1 MHz) and insulation resistance of more than 10 GΩ (100 V dc), the RoHS-compatible surface-mount component has negligible parasitic coefficients. It’s specifically designed to protect dc power supplies in telecom equipment. Size is 1.6 by 8.4 by 8.9 mm3.