Design Con 2015
Breaking News
Comments
Newest First | Oldest First | Threaded View
Sanjib.A
User Rank
CEO
re: Controller PCB problem solved
Sanjib.A   2/26/2012 8:04:58 AM
NO RATINGS
Yes, such a small die shrink should not matter. So I guess it was a pre-existing quality issue, which was missed from previous qualification testing?

pangliuliu
User Rank
Rookie
re: Controller PCB problem solved
pangliuliu   2/20/2012 6:59:29 AM
NO RATINGS
I'm wondering if a small die shrink: from 50nm to 40nm for the memory chip would lead to EMC issues (Radiated Emission?) The specification sheets are exactly same from the manufacturer.

Sanjib.A
User Rank
CEO
re: Controller PCB problem solved
Sanjib.A   1/29/2012 2:57:05 PM
NO RATINGS
If the manufacturer has not informed the change to a die-shrink part, I guess the chip specifications (mostly the timing specs) published in datasheet has not changed. In that case the only change was in the impedance (especially the inductance) of the package pins. Would this make such a huge impact on the board performance unless there was inherent design issue on board, which was on the border line?

sharps_eng
User Rank
Rookie
re: Controller PCB problem solved
sharps_eng   1/29/2012 9:28:30 AM
NO RATINGS
@AussieNeil: 'a non-inverting input track ran parallel to an output track for perhaps a couple of _centimetres_' ; doesn't seem like a die SHRINK to me...!?

AussieNeil
User Rank
Rookie
re: Controller PCB problem solved
AussieNeil   1/28/2012 3:14:42 AM
NO RATINGS
I've seen the same problem with a LM324 op amp die shrink. Reduced yield problems were directly correlated with a die shrink (and no, we weren't informed of the change). In this case, the die shrink was physically obvious (even if the electrical performance change wasn't immediately so) as the IC was bought in slice form and cut, glued and wire bonded into the module. In this case, poor layout practice was a factor (a non-inverting input track ran parallel to an output track for perhaps a couple of centimetres), but modules using the larger die didn't break into oscillation. Obviously the smaller transistors in the shrunk die had a higher cut-off frequency and the internal compensation probably didn't work with as much margin as in the larger, "electrically equivalent" IC. I can understand the op amp manufacturer's point of view in not informing us of the change given the part was electrically equivalent and the die shrink part would probably have been approved on the basis of a desktop review anyway...

WKetel
User Rank
Rookie
re: Controller PCB problem solved
WKetel   1/28/2012 1:03:37 AM
NO RATINGS
When everything else checks out right, then you look for noise, and often that noise is RFI. I wonder if his employers purchasing people approved the substitution of the "die-shrunk" parts as part of a cost reduction, or if the supplier just made the change to improve their profits. IN many cases it happens that "equivalent parts" are not close enough to function as required, and so problems arise when they are used. It was good detective work indeed.

Simplifried
User Rank
Rookie
re: Controller PCB problem solved
Simplifried   1/25/2012 8:55:14 AM
NO RATINGS
Ravender, what prompted you to look for EMI?



Top Comments of the Week
Flash Poll
Like Us on Facebook

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
EE Life
Frankenstein's Fix, Teardowns, Sideshows, Design Contests, Reader Content & More
Max Maxfield

Recommended Reads From the Engineer's Bookshelf
Max Maxfield
2 comments
I'm not sure if I read more than most folks or not, but I do I know that I spend quite a lot of time reading. I hate to be idle, so I always have a book or two somewhere about my person -- ...

Aubrey Kagan

Have You Ever Been Blindsided by Your Own Design?
Aubrey Kagan
37 comments
I recently read GCHQ: The uncensored story of Britain's most sensitive intelligence agency by Richard J. Aldrich. The Government Communication Headquarters (GCHQ), Britain's equivalent of ...

Martin Rowe

No 2014 Punkin Chunkin, What Will You Do?
Martin Rowe
2 comments
American Thanksgiving is next week, and while some people watch (American) football all day, the real competition on TV has become Punkin Chunkin. But there will be no Punkin Chunkin on TV ...

Rich Quinnell

Making the Grade in Industrial Design
Rich Quinnell
15 comments
As every developer knows, there are the paper specifications for a product design, and then there are the real requirements. The paper specs are dry, bland, and rigidly numeric, making ...

Special Video Section
The LT8640 is a 42V, 5A synchronous step-down regulator ...
The LTC2000 high-speed DAC has low noise and excellent ...
How do you protect the load and ensure output continues to ...
General-purpose DACs have applications in instrumentation, ...
Linear Technology demonstrates its latest measurement ...
10:29
Demos from Maxim Integrated at Electronica 2014 show ...
Bosch CEO Stefan Finkbeiner shows off latest combo and ...
STMicroelectronics demoed this simple gesture control ...
Keysight shows you what signals lurk in real-time at 510MHz ...
TE Connectivity's clear-plastic, full-size model car shows ...
Why culture makes Linear Tech a winner.
Recently formed Architects of Modern Power consortium ...
Specially modified Corvette C7 Stingray responds to ex Indy ...
Avago’s ACPL-K30T is the first solid-state driver qualified ...
NXP launches its line of multi-gate, multifunction, ...
Doug Bailey, VP of marketing at Power Integrations, gives a ...
See how to ease software bring-up with DesignWare IP ...
DesignWare IP Prototyping Kits enable fast software ...
This video explores the LT3086, a new member of our LDO+ ...
In today’s modern electronic systems, the need for power ...