[volt-nuts] LTZ1000 at higher currents

m k m1k3k1 at hotmail.com
Wed Oct 19 18:41:14 UTC 2011

Hi John,

The LTZ1000 can be run much harder, but the LTZ1000a can only be run upto about 40-45 mA before the chip temp is up to 125C where the dift is going to be much higher.

I am assuming a 20C lab environment for homebrew kit with decent cooling. But to stop thermal drift you really have to give the chip and pcb poor cooling or dip in parrafin oil.



> From: john at devereux.me.uk
> To: volt-nuts at febo.com
> Date: Wed, 19 Oct 2011 14:14:45 +0100
> Subject: [volt-nuts] LTZ1000 at higher currents
> 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
> _______________________________________________
> volt-nuts mailing list -- volt-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
> and follow the instructions there.

More information about the volt-nuts mailing list