What happend to 320K resistors ?

[james_s]

With SMD you are no hobbyist i think.

I've been using SMD as a hobbyist for at least 15 years. 10 years ago I was etching my own PCBs using toner transfer and routinely using 0603 passives and SOIC chips. I was even able to achieve 0.5mm pitch ICs on self etched boards but that was pushing the process to the limit and was difficult. SOIC though was easy. I can also prototype with SOIC and 0805 passives "Manhattan" style on bare copperclad, and the passives fit nicely soldered between two pads of a normal 0.1" protoboard.

I don't understand the comments about investment, what do you need to invest in? The components are cheap as dirt, you can buy 100 SMD resistors for under $1, they're significantly cheaper than through hole. You don't need much in the way of special tools, I use a $3 set of tweezers and my regular soldering iron. A syringe of liquid flux is helpful at times too.

I remember many years ago people moaning that SMT had killed the electronics hobby. I thought it strange because I never noticed, the transition was almost painless, I didn't throw out my through-hole stuff, I just gradually incorporated more and more SMD as time went on and that's what was available. It wasn't hard, I didn't need any special skills or training, just a few new techniques. It didn't take long for me to prefer SMT because it saved having to drill all those holes.

[floobydust]

The EE generation following us can't use a breadboard anymore, they are obsolete. Through-hole is dying out it was King for experimenting and learning electronics. Now, getting a pcb made, unsoldering a SMT part and flicking it across the bench and putting in a new one, well- not so much fun. And I need a magnifying lens now with old eyes.

For hobby/home products, personal preference, I use through-hole for power stuff, it's not yet a crime. Just easier to work with.
SMT is when a design is stable and I'm able to solder in the IC's. They are constantly getting smaller, no pins, finer pitch. Soon it will be machine assembly only.

But audio can get a bit weird with people discussing "the sound of resistors" in stepped attenuators and DACs, some prefer through-hole i.e. Holco "... original Meggitt Holsworthy, UK made resistors. They give a crisp, full sound, superb."

I just think it's psycho-acoustics or the RF properties (greater self-inductance), big metal film through-hole has a following it seems.

[John B]

Seems like hobbyists have the best of both worlds, where you can utilise SMD for compactness, lower cost and better preservation of a ground plane, while still not being constrained by manufacturing labour costs that would prohibit manual installation of through hole stuff. I still prefer TO-220 devices on heatsinks, and even use *gasp* the odd high current jumper.

[ogden]

The EE generation following us can't use a breadboard anymore, they are obsolete. Through-hole is dying out it was King for experimenting and learning electronics.

It's like saying that computer music will obsolete piano play and 3d printers will obsolete LEGO Just one of many examples why breadboard is far from dying and next generations will use such or alike:

https://www.amazon.com/s?k=arduino+starter+kit

[srb1954]

SMD may have some advantages for non-critical applications but it has some severe disadvantages in high power circuitry:

• The power handling capability for pulse loads for most types of SMD resistors is abysmal
• The ability of SMD resistors to withstand high peak voltages is poor
• The ability to withstand thermal cycling stress with pulsed loads is poor, especially when using lead-free solder
• If the application requires power dissipations more than several watts the heating of the PCB material and surrounding components becomes excessive with SMD parts

If any of the above situations applies the best option is often to stick with leaded parts.

Limiting factor is PCB heat handling properties, not SMT resisors as such. 35W SMT resistor for example: RHFH4Q050R0FE. If you need smaller heater on your PCB, then consider Vishay RCP series or similar.

Of course the limiting factor is the ability for the PCB to handle the heat but by just blindly insisting on using SMT resistors isn't going to suddenly make the PCB perform better; it will just make the problem worse. Just because the letters SMT appear on the datasheet it it doesn't mean you can magically bypass the laws of physics.

If you actually read the datasheet for the suggested RHFH4Q050R0FE resistor you will see that it needs a heatsink to dissipate its rated power. In fact it needs a massive heatsink of 0.4degC/W to achieve its rated power even if you limit the maximum ambient temperature to a paltry 25C. Without the heatsink, and mounted on the recommended PCB footprint, this resistor is only good for 2W dissipation and should have been advertised as such rather than the practically unobtainable figure of 35W.

Similar comments apply to the suggested Vishay RCP parts. These are also heavily reliant on the heatsinking effect of the PCB to achieve their apparent high power ratings. Just sticking the part down on a bit of FR4 is not going to led to success. Unfortunately the datasheet offers no guidance on how to heatsink these resistors and it is left to the circuit designer to sort out the thermal engineering issues

The advantage of using leaded components in these situations is that the component manufacturer has already done most of the thermal engineering work for you. If you mount the leaded component in accordance with the manufacturer's  recommendations and not restrict the air flow around it you can pretty much expect it to perform as advertised without having to put in a lot of effort into thermal engineering issues. With leaded components quite a bit of the heat is taken away by convection before it reaches the PCB so the PCB material and surrounding components run cooler.

Thermal engineering can be one of the most difficult aspects of product design and unfortunately most circuit engineers neither have the knowledge or experience to be proficient in thermal engineering issues. If this thermal engineering it not done properly the product can fail on the market due to unreliability, short lifetime or product warranty costs. Even with an experienced designer thermal engineering can be very expensive in terms of the engineering time and product development timetable.

Low voltage rating of small SMT resistors is due to their (surprise surprise!) size. Simple solution - put multiple resistors in series or use higher voltage rating SMT resistors, usually both. Open parametric search of your parts distributor and see for yourself - plenty of choices.

It's not that simple.

If your circuitry using using fast pulse waveforms then you have to be very concerned about unequal voltage sharing across a string of resistors due to circuit parasitic capacitances and inductances. In some cases you even have to put balancing capacitors across each resistor to force equal sharing of pulse voltages. This requires extra engineering time not to mention the extra cost of additional BOM items, assembly and test time and additional PCB area.

Again, using a single leaded part is often a much better solution. The component manufacturer has done all the hard work of characterising the component under the pulse operating conditions and all the circuit designer has to do is follow the manufacturer's mounting recommendations to successfully use the product.

[floobydust]

The EE generation following us can't use a breadboard anymore, they are obsolete. Through-hole is dying out it was King for experimenting and learning electronics.

It's like saying that computer music will obsolete piano play and 3d printers will obsolete LEGO Just one of many examples why breadboard is far from dying and next generations will use such or alike:

https://www.amazon.com/s?k=arduino+starter+kit

The piano is getting smaller every day but our fingers are the same size. It's the workability of SMT that make it difficult and new parts are not offered in anything but through-hole, for years now.

[coppercone2]

and.. probes cost how much? Dip clip, wonderful. You can do soic but its a little janky, but any resistor or whatever is a total pain in the ass requiring new equipment that takes up alot of room (positioning arms etc)

[ogden]

The advantage of using leaded components in these situations is that the component manufacturer has already done most of the thermal engineering work for you.

Your claim is true for leaded resistors up-to certain power level only. Show me "already done thermal enginering" of this 35W through-hole resistor: PWR220T-35-50R0J  It is not fault of SMT resistor that some can't do thermal engineering If you actually look for it, you can find pre-existing thermal engineering (appnotes) for SMT power resistors. Just an example:  https://www.vishay.com/docs/53047/pra-appn.pdf, https://www.vishay.com/docs/53048/pprachp.pdf

If your circuitry using using fast pulse waveforms then you have to be very concerned about unequal voltage sharing across a string of resistors due to circuit parasitic capacitances and inductances. In some cases you even have to put balancing capacitors across each resistor to force equal sharing of pulse voltages. This requires extra engineering time not to mention the extra cost of additional BOM items, assembly and test time and additional PCB area.

Again, using a single leaded part is often a much better solution.

Just search and you will find 10KV SMT resistors. Even precision low TC parts if needed. Argument could be price, but not as you say "use leaded parts. period."

Fact that you can think of >1KV edge case where even leaded components require careful engineering does not prove your initial blanket statement. Most of applications where one shall start to think about SMT resistor voltage rating and chaining are AC mains. SMT resistors are fine and widely used in such.

[ogden]

The piano is getting smaller every day but our fingers are the same size. It's the workability of SMT that make it difficult and new parts are not offered in anything but through-hole, for years now.

If you want to use modern, highly integrated ICs then be ready to face consequences. When you introduce modern IC, you have to introduce modern way of engineering too. Other option - use old parts or 3rd party DIP conversion adapters/modules.

[GlennSprigg]

All this reminds me of my Security Systems days, where there are EOL (End Of Line) Resistors, next to
the field sensors / reed switches etc., and the electronic control system needed to  see a VERY specific
resistive value, that was not only uncommon, (like 273k or what ever, made up!), but very difficult to even simulate
with a bunch of series/parallel resistors!   
Most (lazy) installers often put them in the control panel!! so totally negating their use!!   

For interest... All higher level systems (Govt places, prisons etc.) utilize a "1-pair-in-the-world" IC Chip
epoxy-moulded into the field 'sensor/etc), and the other sole matching IC in the master control panel,
just for that individual zone/sector.  There's no way to fool them in the field!!   

[Siwastaja]

If you want to use modern, highly integrated ICs then be ready to face consequences. When you introduce modern IC, you have to introduce modern way of engineering too. Other option - use old parts or 3rd party DIP conversion adapters/modules.

In general, modern parts are so much better and so much easier to use. With external component count going down and integration level going up, there is often much less soldering to do with modern parts. So the "consequence" is often positive despite the initial "this must be hard" attitude.

The sweet spot is finding what you need in relatively "easy" SMD packages like SOIC, SOT-23 etc. QFN, BGA, CSP suck with no-PCB prototyping but still, if a really good and otherwise easy-to-use part is available only in such packages, I wouldn't be afraid of using them, just bite the bullet.

It's really strange to see this "SMD is not for hobbyists" discussion in 2021! This was a common theme back some 10-20 years ago, and all but gone for the last 5 years or so.

[Jan Audio]

I am sorry to say the SOIC parts are almost obsolete already.

[Jan Audio]

I always imagine what kind of super chip a 40-pin 8-bitter could be in all that space compared to the smallest part available that is the same.

[Jan Audio]

The EE generation following us can't use a breadboard anymore, they are obsolete. Through-hole is dying out it was King for experimenting and learning electronics.

They need to invent a magnetic-breadboard somehow.

I do agree with you, all those "breadboard-less people" have a windows 10 spyware computer with the latest simulators that i dont trust somehow.

[JohnnyMalaria]

I do agree with you, all those "breadboard-less people" have a windows 10 spyware computer with the latest simulators that i dont trust somehow.

Which don't you trust? The "breadboardless-people", Windows 10 or the latest simulators?

[Jan Audio]

The magnetic-breadboard.

[Siwastaja]

I am sorry to say the SOIC parts are almost obsolete already.

No! SOIC packages are widely used in analog (opamps, comparators), logic gates, ADCs/DACs, gate drivers, SMPS controllers and regulators, and so on...

Modern microcontrollers tend to use packages which give larger number of pins in smaller space, though. While SOIC is quite a miniaturization compared to DIP, it's still huge on today's terms.

[Siwastaja]

I do agree with you, all those "breadboard-less people" have a windows 10 spyware computer with the latest simulators that i dont trust somehow.

Don't want to sound harsh, but are you on drugs?

[Jan Audio]

No! SOIC packages are widely used in analog (opamps, comparators), logic gates, ADCs/DACs,

I could only find some EOL audio DACs in SOIC.

[Jan Audio]

Don't want to sound harsh, but are you on drugs?

Maybe to strong weed, no drugs.
What did you not take serious ?

You trust simulators ?
You say win10 is not spyware ?
You say breadboardless people dont exist ?
All together ?

[Monkeh]

Don't want to sound harsh, but are you on drugs?

Maybe to strong weed, no drugs.

Because THC isn't a drug, just like ethanol and caffeine.

You trust simulators ?

Those who understand their usage and limitations trust them within those confines.

[Siwastaja]

I just don't see the connection from SMD components to Windows 10, but I'm a boring engineer not on drugs. Maybe THC helps creating such interesting connections. I don't say this is a bad thing .

And yes, I "trust" simulators. Just don't blindly. They are tools you need to understand. Really helpful  tools. Designing without one is also a masochistic act.

[Jan Audio]

So you simulate and send to factory ?
Sounds breadboardless.

I agree that my designs take at least a full year to complete, i better call it patience.

[Siwastaja]

Prototyping highly recommended. Fully simulating for all aspects takes more time than using the best tool for the job, which often is a physical prototype.

I personally do not like solderless breadboards, they are source of extra problems I don't want; even if you use highest-quality 3M breadboards and be careful not to damage them, they greatly limit the types of components you can insert. Instead, learn to be proficient with soldering iron, then you can quickly prototype any types of parts, SMD and THT included, without wonky and unreliable connections. Google "Manhattan style prototyping" for pictures.

Sometimes there is no work for a SPICE simulator. For example, a circuit running an MCU interfacing a digital temperature sensor and showing the number on 7-segment display, nothing interesting in analog domain going on you would want to simulate. With such simple example, if you are even a bit experienced, you won't need to Manhattan prototype it, just draw and order 5pcs PCBs, 90% chances you can just start producing it as-is, 10% you made some stupid mistake which you'll fix to the final revision.

Patience is good. Quick iteration cycle is still good even if you have a lot of time in your hands - you can run more cycles and get even better product.

[ebastler]

I could only find some EOL audio DACs in SOIC.

Mouser shows me 27 different audio DACs in SOIC packages which (according to their database) are active products. Quite a few different types are in stock.

Not sure how long-lived the link to the search results will be, but here it is: https://www.mouser.de/Semiconductors/Integrated-Circuits-ICs/Audio-ICs/Audio-D-A-Converter-ICs/_/N-6j741Zgjdhub?P=1z0yhi1Z1z0z5fdZ1z0z7v5

Edit: Oh, and did I mention 130 audio DACs in SSOP/TSSOP packages, which can be drag-soldered by hand with a regular iron as well?