Notes: 1) The Zener impedance is derived from the 1KHz AC voltage which results when an AC current having an RMS value equal to 10% of the Zener current (IZT or IZK) is
superimposed on IZT or IZK. Zener impedance is measured at two points to insure a sharp knee on the breakdown curve and to eliminate unstable units.
2) Valid provided that electrodes at a distance of 10mm from case are kept at ambient temperature
3) Measured under thermal equilibrium and DC test conditions.