Active and future availability of thru-hole parts.

[TurboBob]

I have a number of products/gadgets that I manufacture that are based on the NXP 8051 FA/RC 8 bit parts. They are manufactured in house using thru-hole methods. NXP just EOL'd a bunch of stuff and I seem to be forced to re-design several of these. Since I have reasonably modern, and reasonably well supported development tools for the Freescale stuff ("reasonably" can be debated in another thread) Since I don't want to be in this predicament in the near to medium future, what are the predicted futures for the HC08JK/JL parts? Does anyone have any suggestions other than these parts? I am replacing 40 pin DIP and 44 pin PLCC parts. My other options are the PIC's I think, and/or Atmel/Arduino. Thanks! Bob

[RandyD_]

Turbo_Bob,

Microchip Tehcnology Inc. had acquired some 8051 products with the acquisition of Silicon Storage Technology (SST) in 2010.

They include RB, RC, and RD devices, some in PDIP, that are compatible with some of the EOL NXP parts. 

See cross reference here:

http://microchip-dev/pagehandler/en-us/family/8051legacy/products/home.html

There are others in the family that are not 100% compatible also on this page under the family tabs, but may be close enough for your needs.

Regards, Randy D.

[TurboBob]

wow, excellent!!! this will probably keep me out of trouble Thanks Bob

[tetsu_jp]

There are different SMD systems:

SOIC - Fairly easy to solder using a broad tip, faster than DIL (8 pins to 28 pins)

TQFP - you need flux and desoldering pump or reflow, TQFP44 is easy

leadless QFP, ball grid (BGA) - pick'n'place machine, not designed for manual mounting

TSSOP (0.5 or 0.4mm pitch) - can be soldered manually if need be I would only recommend for prototype

It is possible to do it manually but the part must become aligned nearly 100% or it's very difficult to take out

the extra solder using row soldering. 

If you already have DIL based design use adapter PCBs? There is different pricing,

if you produce them yourself they cost a dollar or less

DIL packaging also is quite bulky compared to SOIC or TQFP (thinking of the waste).

You don't need special soldering tip or extra tin soldering wire.

Reflow depends if you do it professionally for instance use a printer for the solder paste,

a stencil or if you apply it manually. I have good success with small SOT23 (6 lead) parts,

they need rework but the placing is correct using "homegrown" reflow. And I use lead-based

solder for rework the surface tension seems to be higher.

SOIC also aligns correct but always needs rework. Using a broad tip it's fairly easy to pull solder

ball along the pins you don't even need flux.

Maybe you don't want to redesign boards completely to SMD, using adapter PCB might be an option. 

[tetsu_jp]

the pro knows it can have corosion and whiskers. so if you embedd the pickup PCB in epoxy you get rid of the whiskers.

[bigmac · Accepted solution]

Hello Bob,

I might assume that the HC908 device family is probably "not recommended for new design".

For the more recent MC9S08 family, there are very few devices that have a through-hole package option, as you are probably already aware.  For packages with more than 16 pins, we seem to be limited to the following devices.

'GT60  42-pin SDIP

''FL16  32-pin SDIP

'SV16  32-pin SDIP

'SE8    28-pin PDIP

The 'GT60 was one of the early devices released for this family, so may have a more limited life expectancy.  The other devices have a much lower flash memory (and RAM) capacity, but would be comparable with the '908JL devices that you were considering.

Regards,

Mac

[TurboBob]

the SE8 looks interesting for a couple things I have in mind...

Thanks guys

Bob

[RogerSchaefer]

I've used the SE8 with no problems but consider the SV16.

It has twice the memory and has a SPI which the SE8 does not

Here is a project board good for testing

 http://www.batchpcb.com/index.php/Products/55851

Roger

---

[donw]

hi Bob

          I was in the same place a copule of years ago. Rather than go to JK8, etc which I guess will be EOL'd before long, I moved to one SMT micro part (S908JM60) & hand solder it for small runs. Its leg spacing is wide enough for hand soldering under a magnifing glass (operator age dependant!). The most important trick was to use a small gauge solder, to stop solder bridges.

I worry about young engineers in a few years time when only narrow spacing SMT parts are available....

[TurboBob]

as it turns out, Atmel still makes thruhole parts in this "series" which should be compatible with minor software tweaks. So, as long as they stay available, I'm ok for now. The magnifying glass idea will not work, the volumes are high enough that its not practical, and my 'assembler' is no spring chicken.... But, future products are all going SMT (because my assembler is "no spring chicken"...... I agree that the hobbyist has little recourse nowadays, other than Arduino / Basic Stamp / etc. style modules. Bob

[rocco]

Hi Bob and Don,

I made the switch to surface-mount, and found it to be quicker and (somewhat) easier than through hole. It does cost a little more, because you need to buy a paste-mask.

When I order PCBs, I order them with a solder-paste mask. So it takes me about 30 seconds per board to screen the solder-paste on all of the pads. But you can be confident that the right amount of solder is in place.

Then I place the components, which is a little trickier if they are very fine pitched. I use a lot of .5mm pitched, large pin-count (up to 208) ICs, so I use magnifiers to place them. The other parts, especially the caps and resistors, are pretty easy. Once placed, the paste holds the components in place, even if you turn the board upside down (which I don't recommend).

I then pop the board into a toaster-oven to reflow the solder. It takes about 5 minutes to reflow. No soldering iron needed.

So both placing the solder and reflowing the solder takes place in one swell-foop. Placing the components is the only time-consuming part, but no more time-consuming than through-hole parts.

A side note: I like to use through-hole connectors, for a couple of reasons. So I skip all through-hole parts until the board is out of the toaster-oven, and then add them by hand, the same way you do now. So through-hole parts actually become an extra assembly burden.

It is so worth it, to be able to use almost any component made (although I still won't use ball-grid arrays).