Searching some BZX884 2V4 & 3V6 zeners for test

Can't you get samples from a rep?

John

Unless it's a boutique value and only produced when a large enough order comes in.

That's what they make TL431's for... sharp "knees". ...Jim Thompson

I know that, and that's why I need some to measure and make a test. I'm not terribly exigent for the reg and the circuit will withstand that, but depending on it's real curves it might pose a startup problem I want to check. Fairchild has some interesting curves in

Why try to use it? Because it's the tiniest reference I've found, even if crappy. Only 0.6x1mm, with leads under the body. I'll have to cram 27 components on a 7mm diameter pcb, plus 4 connect pads. (4 layers, microvia in pad) Some others are available in a frighteningly huge SOD523/SC79 0.9x1.7mm but I'm afraid I can't afford the 2.5 area.

I've checked the usual suspects and none have stock, so back to square one.

Oh, and reps, here in France, are really unhelpful. Yeah, I'm a just a (no, not a gigolo) consultant (a pretty rare species here), and the customer will be delighted to use half a wheel a year, so nothing to dream about for the reps.

If you can let off a little more about your circuit maybe there are other options. For example the LT6700 comes in a 2mm by 3mm pack, contact pads underneath, and in it you get two comparators plus a nice

But if you consider it write me an email. It has an IMHO nasty bug during startup that might trip you up (it almost did in my case).

From past experience I can only tell you that measuring a few samples guarantees nothing with low voltage zeners. The shipped reel might be different. You really need to get the quality control limit sheets from the manufacturer. Done it several times, they usually give that to you but sometimes you have to sign an NDA. Otherwise you may end up with a product that runs fine, suddenly your client sells more than anticipated, another reel is purchased and ... boink ... game over. And then they all look at Monsieur le consultant :-)

It is also not guaranteed that all the zeners on one reel are from the same wafer or even the same production week.

Isn't it sort of idiotic to look at zeners below ~5V, when there's the TL431, even CMOS versions? ...Jim Thompson

Jim Thompson a écrit :

Have one in under a 1mmx1mm area, pads included package?

I of course have looked that path. But you've made the die too big :-)

I didn't design that particular circuit. It dates to the early '70's when I was making switchers for GenRad. I design similar structures into my custom chips... almost monthly ;-)

Have you pursued the CMOS version? It should be available in a small package. ...Jim Thompson

IIRC, I did look at some CMOS version, because I could have used it as an opamp with offseted input, which is almost what I'm doing, but I think I came with nothing. He he... Have a reference?

one.

Look at TLV431 and TLC431. ...Jim Thompson

one.

Smallest is SC70 or you have to use die and tar blob :-(