[volt-nuts] LTZ1000 at higher currents

[Frank Stellmach]

Hi John,

as far as I remember, higher Zener currents alone (i.e. excluding 
temperature rise effects) let the pn structure age / drift faster 
compared to operation at lower currents.
This might probably be an exponential effect, so I would not increase 
the Zener beyond the given limit of 5mA at all.

Remember, a Zener pn junction is operated in reverse mode, and charge is 
highly accelerated inside the silicon bulk material by the Zener 
potential. Higher currents will therefore interact stronger with the 
silicon crystal structure, than lower ones, that means it will create 
more permament defects on the long run, which gives rise to stronger aging.

Also, this is not a discrete Zener component, but a very delicate 
sub-surface structure, optimized for lowest drift, but presumably not 
for high currents. 10, 20 or even 30mA will for sure damage the Zener.

Frank