[volt-nuts] LTZ1000 at higher currents

John Devereux john at devereux.me.uk
Wed Oct 19 13:14:45 UTC 2011

Hello everyone,

Is there some reason why LTZ1000s are not run at a lot higher current
than 5mA?

Thermal resistance is 80'C/W, or ~0.5'C/mA. So it would seem OK to run
it at 10, 20, 30mA before seeing serious problems due to raising the
temperature too high. 

The datasheet noise graph shows a big fall in noise level between 1 and
5mA, so this ought to reduce the noise further. I am not sure how far
down in frequency this improvement continues. On the datasheet the
"noise gap" widens more and more with lower frequency, does this extend
to frequencies so low they would be regarded as long term drift? 

There is no current limit for the zener that I can see (of course there
will be one eventually). 

The "Pickering patent" uses pulsing to achieve a high current in what is
obviously a LTZ1000, the stated reason being to minimise "VLF and long
term instability".

But it seems like even a higher DC current could be of benefit.


John Devereux

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