From: Fred Bloggs
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Subject: Re: WTD SOT23 Low Current Zeners - 50k pcs required
Date: Tue, 05 Nov 2002 13:29:05 GMT
NNTP-Posting-Date: Tue, 05 Nov 2002 05:29:05 PST
Organization: EarthLink Inc. -- http://www.EarthLink.net
Winfield Hill wrote:
> Winfield wrote...
>>Joseph Goldburg firstname.lastname@example.org wrote...
>>>I am looking for the following Philips obsolete parts
>>>BZX99 or BZX399 low current zeners (graded at 50uA)
>>> Voltage 6v2
>>>Data sheets available from
>>Nobody is stepping forward, so I'll try to answer. It's
>>sad to see the BZX99 discontinued, the 50uA grading was
>>very nice compared to the 5mA, etc., for more common
>>parts like the BZX84. Offhand I can't think of an exact
>>replacement part. But fortunately your need is for 6.2-
>>volt zeners, because zener diodes in the 5.1 to 6.8-volt
>>region have much better voltage regulation than at other
>>voltages (see the curves in AoE page 332). They get down
>>to under 100mV/decade, which means that the change for
>>5mA parts being used at 50uA will probably be less than
>>the 5% zener tolerance. Futhermore, you can assume the
>>BZX84 types will be say 3 to 4% lower voltage than BZX99
>>and adjust another component value appropriately to be
>>even closer in your circuit's overall parameter spread.
> Hmm, it'll likely be much less than 150-250mV... But if
> it's an issue for you, consider a Zetex ZRT062 regulator,
> acts like a 2% 6.2V zener above 150uA, $1.39 from DigiKey.
> - Win
Diodes, Inc. has a line with 1% and 500uA in surface mount.