The Voltage-Current characteristic of a POSISTOR® depends primarily on resistance, Curie Point temperature and ambient temperature.   The protective current range will move according to these factors. The “protective threshold current range” chart shows the protective current range (including tolerance) between “hold current range” (normal operation) and the “trip current range” (high impedance operation).  Such charts are provided in the Murata catalog and web site for individual POSISTOR® products.