AN315 Datasheet | Silicon Labs

Description of Si3400 Protection Si3400 and Si3401 protection consists of a stack of ten, high-current 6.2 V Zener diodes. These lower-voltage Zener diodes have a lower temperature and process variation than a higher voltage Zener clamp, such as an SMAJ58A. Consequently, the range of initial breakdown for the plete stack is much tighter: typically <1 V variation at room temperature (as pared to 6.8 V for the SMAJ58A) and <4 V variation over - 40 to +85 °C. Due to the incremental resistance of the Zener diode stack, the voltage at 0.5 A current typically increases to 73 V, and the voltage at 5 A current is less than 79 V for the Si3400's on-chip protector. As a result, the Si3400's maximum clamping voltage of 79 V is considerably lower than the 90 to 100 V range of a typical SMAJ58A TVS protector. Because the Zener stack is part of the Si3400's internal circuitry, it bees straightforward to...