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I am somewhat familiar with latchup (parasitic transistors in the body of a CMOS device that are activated by over- or under-voltage conditions). However, I have seen some devices that advertise "Latch-Up Performance Exceeds 250 mA Per JESD 17", while others say "Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II"

What exactly does this mean? Specifically, what is the mA value in reference to?

Which one of these is better? I think the JESD 78 standard is newer, so is it also "better" despite having a lower mA rating?

stevenvh
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ajs410
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2 Answers2

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JESDxxx are standards.
Date does not necessarily indicate goodness.

Currents are what can be injected into pin by voltage outside rails without causing latchup.
100 mA is good,
250 mA is very good.

Russell McMahon
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Both are standsrd tests defined by JEDEC, a member of the Electronic Industries Alliance (EIA).

JESD17 (the document is not available anymore) is an old standard, dated 1988, which has been replaced by the newer JESD78 (you need to register to download the document). So you can consider the performance test with JESD17 "less accurate" for newer devices than the one defined by the newer standard.

From the document:

As these technologies have evolved, it has been necessary to adjust this document to the realities of characterization with limits not imagined when the first latch-up document was generated some 25 years ago.

But if the component you have is older than the latest standard, you can assume that the testing has been made with the newest (at the time) version of the standard, and consider it reliable.

Moreover, the newer one may have a lower rating because, being newer technology, operates at lower current/voltage ratings, or it's just less rough.

clabacchio
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