3. SURGE CURRENT (Ir) - Surge current is specified as the maximum allowable peak, non-recurrent square-wave

current with a pulse width, PW, of 8.3 ms. The data given in Figure 5 may be used to find the maximum surge

current for a quare wave of any pulse width between 1 ms and 1000ms by plotting the applicable points on

logarithmic paper. Examples of this, using the 6.8v ,

is shown in Figure 6. Mounting

).

4. VOLTAGE REGULATION (Vz) - Test conditions for voltage regulation are as follows: Vz measurements are made

at 10% and then at 50% of the Iz max value listed in the electrical characteristics table. The test currents are the

same for the 5% and 10% tolerance devices. The test current time druation for each Vz measurement is 40+/- 10 ms.

APPLICATION NOTE:

1N5338B THRU 1N5388B

Since the actual voltage available from a given Zener

diode is temperature dependent, it is necessary to determine

junction temperature under any set of operating conditions

in order to calculate its value. The following procedure is

recommended:

power dissipation.

temperature and may be found from Figure 4 for a train of

power pulses or from Figure 1 for dc power.

from Figures 2 and 3.

Under high power‐pulse operation, the Zener voltage will

vary with time and may also be affected significantly by the

zener resistance. For best regulation, keep current

excursions as low as possible.

Data of Figure 4 should not be used to compute surge

capability. Surge limitations are given in Figure 5. They are

lower than would be expected by considering only junction

temperature, as current crowding effects cause temperatures

to be extremely high in small spots resulting in device

degradation should the limits of Figure 5 be exceeded.

KI SEMICONDUCTOR