S12G in 48-QFN

[vpgusiatnikov]

I happen to like the QFN. It takes less room (per unit of functionality). I designed a S12GN...FT into a new design for a startup, making sure that parts were in stock.

Now a month later, when it's time for prototype build, they aren't. And when I asked Avnet, here's the answer I got in its almost complete entirety:

"This is a non-stocking item with high min order quantities no recommend for new designs."

Can someone from Freescale possibly comment? In particular, the "no recommend" is truly scary, as it contradicts the celebrated 10-year life program. I very much hope the Avnet rep didn't know what she was talking about, but maybe she did.

Are the GNs not fully rolled out yet? Or is it possibly a packaging-related issue similar to the ITC dispute of 2009/2010, possibly also affecting other parts in QFNs? I have a number of other designs that use the S12P in QFN and would like to know.

I lost my FAE contacts when changing jobs, so can't readily call up someone and try to get an answer.

[iggi]

Hi,

I think the lady at Avnet knows what she talks about.

The true is that the parts in QFN package are no longer manufactured. But, there are active parts in the QFN package with exposed pad (QFN-EP). These are S12GN32 derivatives.
Family 16-bit MCU|Freescale

However, the parts seems not to be available on disties stock. I suppose you would need to order high quantity which will be manufactured and delivered to you.

About the fact 'no recommend for new designs' the Avnet said, well i am not sure about that. It crosslines with the Freescale product longevity program where S12G availability as Auto MCU is guaranteed for 15years starting 2010.

Still, there are several S12G derivatives and dozens of variants (depending on flash size, package size, temp range) active and available, so in case some are discontinued there are direct replacements (QFP packages)

Regards,

iggi

[vpgusiatnikov]

Thank you iggi! I tried to be specific in my original message: "S12GN...FT", indicating QFN-EP package, but I guess not specific enough. I am aware that the non-EP QFN is discontinued.

So, my question remains:

Is the QFN-EP (-FT package suffix) a good package to use? Will it suddenly go away?

Do I understand your answer correctly that a specific part in a specific package is not guaranteed for longevity, only a class of parts (such as the whole class of S12GN) is, and the replacement parts may not be pin compatible nor function compatible with already designed in parts? This complicates life significantly, and I think this is not how many engineers understand the longevity program. It's not really a longevity program any longer. Freescale indicates the following:

"A migration to a product that is form, fit and function compatible may be required".

However, your reply seems to indicate that one may have to switch from a QFN to a QFP, that is to a part in a different package and possibly with a different pinout---no longer "fit compatible"!

I was hoping longevity means that a specific part number, such as S9S12GN32F0CFT, or an exact package and functional replacement (e.g. MC9S12GN32MFT, should MC- parts be introduced on the GN), is guaranteed available, but your answer seems to strongly indicate otherwise.

After my original message, I also looked for availability on the S12P in the QFN-EP package, which I designed on another product several years ago, and it looks grim. Can you confirm or deny that the QFN-EP is going away?

[iggi · Accepted solution]

I understand you want to be 100% sure about the S12GN32 (in QFN-EP) longevity.

Since the entire S12G family is included in the longevity program, this is valid for all derivatives.

Here is the screenshot from the FSL webpage clearly indicating the product life:

I cannot confirn neither deny anything about the mentioned package.

The only thing is sure. If you want the parts in this package, you would need to order high quantity.

Btw, 48-pin LQFP/QFN packages for S12GN16 and S12GN32 have the same pinout (see MC9S12G ref. manual).

Regards,

Ivan

[vpgusiatnikov]

Thank you Ivan, the question in answered.

BTW, a 1000-piece buy of a $2 part is far less of a problem than a 16-week lead time in almost all environments save a hobbyist. And although the LQFP and the QFN-EP have the same pin numbering, pitch, and plastic size, the LQFP has an about 10 mm square footprint and the QFN, about 8 mm, that's 36% of board area that is better used for other purposes. The LQFP does not fit into the QFN-EP footprint and is also taller.