Digital Potentiometer Arduino

I found the AD5171 Digital Potentiometer project: https://www.arduino.cc/en/Tutorial/DigitalPotentiometer

I ordered the parts necessary for incorporating this application for periodic error control in my star tracking device for long exposure tracked star photography (the programmable pot will regulate motor speed in a repetitive pattern).

But now my problem: I can only find the AD5171 in SOT-23-8 casing. That means it is infinitesimal small by my standard, approx 3x3 mm, with 8 legs to solder...

It does not at all look like on the image in the above linked project: https://www.arduino.cc/en/uploads/Tutorial/AD5171_bb.png - It is a lot, lot smaller.

Is there an AD5171BRJZ10-R7 in a bigger casing, suitable for a breadboard, to find somewhere?

If not, I have found this adapter: http://www.proto-advantage.com/store/product_info.php?products_id=2200100

Still the 8 microscopic legs has to be soldered on to this little board.

  • Is this possible with a soldering iron and normal soldering skills?

Advice on soldering technic (I have googled some, but found no video with someone actually soldering an IC this small)?

Any better solution to my problem?

Regards Nokturner

AD5171 SOT-23-8 measures (on page 22): http://datasheet.octopart.com/AD5171BRJZ10-R2-Analog-Devices-datasheet-8546.pdf

Youtube "drag soldering" - you tack one pin down, put flux on, and it's like magic. First time doing drag solder was better than I'd ever done without knowing that trick. Lots of videos and demos online. Use leaded (63/37) solder, not the unleaded shit - lead free solder is much harder to work with. SOT-23-8 is do-able, but it's unpleasant. SOT-23-6 was already a bit annoying without squeezing another set of pins in there.

Frankly, I avoided the analog devices digipots partly for that reason! Microchip has a really nice line of digipots, with a more sensible protocol than the analog devices ones, in packages that are easier to solder, and (at least when I was looking) at generally better price point than comparable digipots from AD. They've got ones in SOIC (trivial to solder to breakouts using drag soldering - I prefer soldering SOIC over DIP now), and even some in DIP packages.

Thank's for your fast reply. Then I know that drag soldering maybe is doable. I will give it a try, got three IC:s to experiment with and I only ned one functioning...

Also thanks for the advise on leaded solder. Found solder paste on AliExpress to go with 63/67 solder.

Microchips digipots sounds nice, especially when they go in more solder friendly casings. Unfortunatelly this is my first Arduino project and my knowledge in programming and electronics are limited. Guess I have to stick to the description in the Arduino project I linked with the AD5171. That is unless there are a good description on the net somewhere how to use a Microchip digipot the same way with an Arduino.

Why don’t you use a SURFBOARD ?

A surfboard looks nice, didn't know they existed. But I don't seem to find a place to purchase? Find them neither on AliExpress or ebay. No where else either where I can order (live in Sweden). Must be dumb in finding them, this little thingy cant be that rare?

Edit: I found this on ebay: http://www.ebay.com/itm/5-Pcs-SSOP8-SOT23-to-DIP8-adapter-PCB-SMD-Convertor-/291647989662?hash=item43e793279e:g:c8gAAOxyOM9R6d93

Looks good?

No, not solder paste - solder paste is awful for hand soldering. It's for reflow oven soldering.

For hand soldering, get some "no clean gel flux" and some 63/37 rosin core solder.

I have a lot of fairly nice (if I do say so myself) breakout boards for SMD parts which I ship internationally - but none for SOT-23-8. That's a pretty uncommon one; most manufacturers use MSOP or something like that. Analog Devices just seems to do things their own way. I'm sure there are some breakout boards available - low-grade breakout boards from china are available for almost every package.

DrAzzy: No, not solder paste - solder paste is awful for hand soldering. It's for reflow oven soldering.

For hand soldering, get some "no clean gel flux" and some 63/37 rosin core solder.

I have a lot of fairly nice (if I do say so myself) breakout boards for SMD parts which I ship internationally - but none for SOT-23-8. That's a pretty uncommon one; most manufacturers use MSOP or something like that. Analog Devices just seems to do things their own way. I'm sure there are some breakout boards available - low-grade breakout boards from china are available for almost every package.

I am most greatful for help in this, for to be able to drag solder this IC I feel that I need all the advice I can get in the right soldering materials.

I think I found the solder: http://www.aliexpress.com/item/New-Welding-Iron-Wire-Reel-100g-3-5oz-FLUX-2-0-1mm-63-37-45FT-Tin/32583004483.html?spm=2114.01010208.3.2.VIIbdb&ws_ab_test=searchweb201556_7,searchweb201602_5_10057_10056_10055_10037_10049_10059_10032_10058_10017_10060_10061_10062_10063_412,searchweb201603_6&btsid=de2f085c-9de3-44bc-a97d-b11cf6d4cc01

But the "no clean gel flux" I find is for lead free soldering? It's also quite expensive: http://uk.farnell.com/cif/f42202/flux-no-clean-gel-syringe-of-10/dp/1643121

I would be most greatful if someone could give a link to suitable flux where I can buy it, not robbing the bank.

I use this stuff - https://www.amazon.com/QuickAlloy-Flux-30cc-Syringe-Nozzle/dp/B00DAN3XHQ/ref=sr_1_1?ie=UTF8&qid=1470255555&sr=8-1&keywords=no+clean+gel+flux (that is several lifetime supplies for a hobbyist) - search "no clean gel flux" on ebay/amazon - "reputable" vendors like Farnell charge through the nose for solder and flux, just crazy prices.

That solder looks right, though I find 1mm a little thin for most work. Maybe not this task, but in general.

Thank's for the link. Unfortunatelly they don't ship to Sweden. What about this flux? If one read the label on the picture it sounds poisonus, but it's them only thing resembling "no clean gel flux" I found.

Ya, that stuff looks fine.

Everything is "known" to the state of california to cause cancer, they have wacky rules there. And who the hell cares if your flux contains lead, you're using it with leaded solder!

Ok, I think I will be set for this :slight_smile: Report back here how it all went with the soldering in maybe a month. The items have to arriwe first, and then I to get the soldering done. Thank’s for the help!

Just a comment of smd stuff with paste ..

I've made quite a few protypes by dotting pads with a paste from a syringe, place components with tweezers, heating board on a hotplate to about 150C , then gentle hot air work to finally melt the solder.

Does a lovely job

regards

Allan.