Chips/parts you hate working with... - Page 1
Forum section: electronics / projects

author: george graves
author_rank: Super Contributor
timestamp: August 12, 2014, 09:12:39 am
content: Name and shame them....What parts always end up biting you in the ass.....Or...What parts have you worked with that ended up causing a problem/re-design/smoke/fire....

author: bwat
author_rank: Frequent Contributor
timestamp: August 12, 2014, 09:28:29 am
content: Quote from: george graves on August 12, 2014, 09:12:39 amI see, this is an intelligence test, one which those that admit to repeated application of duff parts fail.

author: rob77
author_rank: Super Contributor
timestamp: August 12, 2014, 09:44:52 am
content: there is none. all parts are just parts. i use only parts i like and which are available and suitable (hobby projects).but what i really hate is the marketing bullshit on the first page of the datasheet - and that apply for the vast majority of the parts

author: AndyC_772
author_rank: Super Contributor
timestamp: August 12, 2014, 09:47:40 am
content: Quote from: bwat on August 12, 2014, 09:28:29 amWe don't always get the choice. I dislike using anything that comes in a QFN or similar package, because even when manufacturers swear they can handle them with no problems at all, I just know I'll end up looking for open circuits where they've not soldered properly. Not ideal when you're trying to find the *real* bugs on a first prototype.

author: con-f-use
author_rank: Unknown
timestamp: August 12, 2014, 09:49:02 am
content: I ordered vishay VLM#1300 smd LEDs. I swear to god, they are made out of candle wax and spit. No matter how careful I solder them, a few always fall apart or die a heat death.

author: Artlav
author_rank: Frequent Contributor
timestamp: August 12, 2014, 10:24:12 am
content: TQFP and like with 64 and more pins.They are a pain to etch for and solder.

author: deephaven
author_rank: Frequent Contributor
timestamp: August 12, 2014, 10:38:37 am
content: Anything that I've designed in before reading the errata

author: Kjelt
author_rank: Super Contributor
timestamp: August 12, 2014, 11:14:54 am
content: parts where the pins are so close together that even with a pro stainless steel SMD stencil the state/temperature/fluidity of the solderpaste matters if you have a lot of shorts between the legs or a perfect reflowed result.

author: brabus
author_rank: Frequent Contributor
timestamp: August 12, 2014, 11:23:09 am
content: Connectors with unclear mechanical and footprint dimensions on the datasheet.Tremendous afternoons passed with connector, gauge, pencil & paper.

author: Richard Head
author_rank: Frequent Contributor
timestamp: August 12, 2014, 11:44:59 am
content: Any SMD part that doesn't have exposed pins. Can't measure anything, can't remove it (easily) and can't visually inspect the connections.

author: calmtron
author_rank: Regular Contributor
timestamp: August 12, 2014, 01:33:29 pm
content: Cheap chips from eBay with marginal stability (factory rejects / pirate copies / crap). I guess I'll never learnLast time it was a MC34063 which I figured was to cheap to copy, but of course it ended up widlarized together with its cheap brethren.

author: free_electron
author_rank: Super Contributor
timestamp: August 12, 2014, 02:15:42 pm
content: Anythng that looks like a glass balloon with bits of scrap metal in it...

author: Refrigerator
author_rank: Super Contributor
timestamp: August 12, 2014, 02:33:08 pm
content: Parts that don't have datasheets of them.

author: luky315
author_rank: Regular Contributor
timestamp: August 12, 2014, 03:44:32 pm
content: I hate working with Infineon parts. I worked for them and it was a terrible experience. I was glad to get another Job. Using Infineon products brings back bad memorys.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 12, 2014, 07:02:00 pm
content: Marvell and Qualcom parts, for their stance on datasheets and two-row QFN packages that need 3.5 mil t/t on outer layers to route.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 12, 2014, 07:06:22 pm
content: Quote from: brabus on August 12, 2014, 11:23:09 amOMG yes! Hirose parts are terrible for this... I mean they specify the font and embossing depth of the manufacturer logo, but if you want the distance between rows of pins center-to-center, you need to print out the PDF at 12000DPI and look with a microscope.Or they specify so many other dimensions, so that three people arrive at four different results...argh.

author: SirNick
author_rank: Frequent Contributor
timestamp: August 12, 2014, 07:29:49 pm
content: Yep. Molex has that tendency too. A hundred measurements all referencing each other so you have to break out graph paper and an abacus to get the one dimension you care about.The other part (vendor) I hate is E-Switch. They alwayshaveHADexactly the switch I want.

author: Unknown
author_rank: Unknown
timestamp: August 12, 2014, 09:58:37 pm
content: AMD Processors... they are packed full of the magic smoke.

author: Corporate666
author_rank: Unknown
timestamp: August 12, 2014, 10:26:36 pm
content: Quote from: SirNick on August 12, 2014, 07:29:49 pmI hate that also.Datasheet space is free... so why they leave important dimensions to be derived from other dimensions makes no sense. It always reeks to me of an overly eggheaded engineer who abhors redundancy even at the expense of ease of use.

author: wraper
author_rank: Unknown
timestamp: August 12, 2014, 10:35:13 pm
content: Quote from: n45048 on August 12, 2014, 09:58:37 pmWhere did you see at least a single one?Except that 15 years old video on youtube.

author: Unknown
author_rank: Unknown
timestamp: August 12, 2014, 11:41:06 pm
content: Quote from: wraper on August 12, 2014, 10:35:13 pmNothing in the last 5 years since I changed professions (I'd like to think AMD have sorted out their overheating/self-destructivefeaturesproperties). I personally swore off them back when the AMD K6 was around. Since then, I've seen several crispy AMD's first-hand in other machines I've worked on over the course of 10+ years in IT industry.(Although the YouTube videos are amusing too!)

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 13, 2014, 01:03:24 am
content: Chips where the details needed to repurpose or hack the devices containing them are unavailable.FPGAs are my current love/hate. They are really fun to play with, except there are so many rules in how to make a working design. Tiffany Yep makes it all look so easy, except it's not...

author: SL4P
author_rank: Super Contributor
timestamp: August 13, 2014, 01:40:16 am
content: DIN connectors. The type used in 30 year old AV equipment.They short-out/melt and do all the things you don't want - before you try to shoehorn the conductors, insulation and strain relief back into that 1/2-inch cylinder.AArgh

author: SirNick
author_rank: Frequent Contributor
timestamp: August 13, 2014, 03:15:43 am
content: Heh. And what could possibly be the problem with using the same connector for power, serial, and A/V signals?

author: coppice
author_rank: Super Contributor
timestamp: August 13, 2014, 03:35:17 am
content: Quote from: free_electron on August 12, 2014, 02:15:42 pmHow are you going to reheat your pizza without one of those?

author: GK
author_rank: Super Contributor
timestamp: August 13, 2014, 04:08:54 am
content: This part was a nightmare:http://www.analog.com/static/imported-files/data_sheets_obsolete/311507236AD9501.pdfAnalog devices made a series of these programmable delay generators, with either TTL or ECL outputs. They were garbage. They were extraordinarily sensitive to noise onanypin and next to unusable in almost any logic environment. Several 10's of uV on a logic pin and the internal comparator would trigger erratically on the internally generated analogue ramp voltage. The whole series is obsolete now - I think I know why.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 13, 2014, 04:18:08 am
content: Quote from: brabus on August 12, 2014, 11:23:09 amLCD displays (hurray for cheap Chinese drafting labor?) and connectors (FPC and others) seem to be the worst offenders.Regarding redundancy: you're not required to note dimensions that are fully defined elsewhere, and often, you don't want to. However, there is still a recognized method to do so: the measurement is written in parenthesis, indicating a derived value, as a note, not as a design reference. (Thus, the tolerance on that number may be substantially worse than those around it; this isn't necessarily the case, like if you have a row of pins with pin-to-pin spacing "<number> +/- <tol> NON CUM.", then call out the number of pins. The dimension between outermost pins will be both a derived value, and having tolerance exactly <tol> because it's non-cumulative.)Quote from: luky315 on August 12, 2014, 03:44:32 pmMy condolences -- that sucks, from anywhere.That's not what I've heard about them though, at least recently. I've even had a few questions answered reasonably and promptly, at least from those respective departments. Their parts are generally good quality and sufficiently specified.Tim

author: Kjelt
author_rank: Super Contributor
timestamp: August 13, 2014, 06:58:27 am
content: Quote from: T3sl4co1l on August 13, 2014, 04:18:08 amOuch you woke up an very old frustration:Those LCD zebra stripes , if you do not have the perfect 100% balanced mechanical pressure over the entire display some digits will not workAnd those once clipped on connectors are also bad when they are corroded, they can break off when you are only looking at them

author: wraper
author_rank: Unknown
timestamp: August 13, 2014, 07:50:01 am
content: Quote from: n45048 on August 12, 2014, 11:41:06 pmThey have internal thermal protection/throttling since Athlon 64 and that was 10 years ago. Before that they did have a temp sensor but purely relied on motherboard that it will handle overheating correctly (often they did not).

author: poorchava
author_rank: Super Contributor
timestamp: August 13, 2014, 08:57:28 am
content: PIC16, PIC18, dsPIC30 - bugs on bugs chasing bugs which are being fed with bugs. Bastards owe me several weeks of my life which I spent chasing silicon bugs that sometime weren't even in errata sheet.Chinese 'bead' 1W LEDs - i have yet to score a success on reflowing those in an oven without lens melting.

author: Whales
author_rank: Super Contributor
timestamp: August 13, 2014, 09:24:35 am
content: Flat flex and its connectors. I've broken a lot of them when trying to work out how they operate -- every laptop seems to use at least 2 different latch styles. The tiny plastic arms/fingers that hook them into place or guide them commonly can't take a 'normal' opening force if you operate them in the wrong direction.A bright light and a lot of patience pay offCorroded flat-flex is another story. Keep your old electronics dry!

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 13, 2014, 10:53:32 am
content: Quote from: poorchava on August 13, 2014, 08:57:28 amI've done "3W" Chinese LEDs by 'hot stove reflow' on copper clad. Your oven isn't heated from the top by any chance, is it?I've desoldered 7-seg displays before, that kind of gooed to bits trying to pull them out...Tim

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 13, 2014, 11:25:28 am
content: Quote from: free_electron on August 12, 2014, 02:15:42 pmA Hewitt Mercury Arc Rectifier?

author: Gribo
author_rank: Frequent Contributor
timestamp: August 13, 2014, 11:49:17 am
content: I hate Murata's DLW family of common mode chokes. Is it so hard to add an orientation mark to a symmetrical component?

author: void_error
author_rank: Frequent Contributor
timestamp: August 13, 2014, 11:57:22 am
content: LCD displays with M2.5 mounting holes when they have enough room on the PCB to make M3 holes, and parts with unclear pin function descriptions (does that pin have any practical use or not).I also really hate inductors with crap datasheets which doesn't specify the core material and/or operating frequency range. It should be a technical document not marketing crap.QFN packages are also on the list although TQFP are perfectly fine. The only advantage I see in QFN is the small footprint but that is usually outweighed by the difficulty to solder/desolder them. That bloody annoying thermal pad on the bottom ruins everything.

author: MagicSmoker
author_rank: Super Contributor
timestamp: August 13, 2014, 12:34:48 pm
content: I've had good luck with QFN packages, yet seem to always have soldering problems with TQFP's... Guess this is very much a YMMV kind of thing.That said, I also have lots of problems with SMT LEDs... they seem unusually susceptible to damage from reflow soldering, and this is with leaded-solder; I can only imagine how well they do with lead-free soldering.

author: alanambrose
author_rank: Frequent Contributor
timestamp: August 13, 2014, 04:00:51 pm
content: I like the QFN/DFNs- the ones I hate are the ones only available in SOIC.I recently designed in some ADG5412 switches in LFCSP packages from the datasheet only to find when I got the boards back to make up ... that no one actually stocks the LFCSP. My stupidity I guess, but why do they have that package on the datasheet if they don't actually make it available?Alan

author: Corporate666
author_rank: Unknown
timestamp: August 13, 2014, 06:06:01 pm
content: Quote from: alanambrose on August 13, 2014, 04:00:51 pmYES! That is another huge issue I hate dealing with. A lot of companies will have tons of variations and then none of them are ever available. When you inquire, they will tell you that there will be a MOQ of 10,000 or 20,000pcs. Even for large companies - who would commit to 20k of something you can't even get a few of for testing?And actually, Cree is notorious for this with LED's... they will list tons of CRI and flux bins, and they will hype their latest LED to the max about how it produces 200lm/watt at 95CRI or some nonsense. Then you see there are a couple of reels available at the distributors' websites in 80CRI and 90lm/watt flux bins... and the sales droids will tell you they can happily supply the higher flux bins (at triple the price) if you're able to commit to 50k pcs orders. Ridiculous.

author: con-f-use
author_rank: Unknown
timestamp: August 13, 2014, 06:20:38 pm
content: Amen ondiethe Cree thing!

author: SirNick
author_rank: Frequent Contributor
timestamp: August 13, 2014, 07:13:50 pm
content: Minor gripe: TI's TPS54226 switching regulator. There's an Enable pin, and a Vreg pin that supplies 5v for control circuitry. The Enable pin is diagonally opposite from the Vcc pin (with a ground pad between) but in my layout, the Vreg pin was fairly easily accessible, so I thought "OK, I'll tie Enable to Vreg". Predictably, it turns out Vreg is ALSO disabled when Enable is LOW, so my prototype board had a bit of a chicken and egg thing going on.To be fair, I realized this was a possibility, and combed through the datasheet looking for confirmation one way or another -- and therein lies my chief complaint. There isn't one word about this either way. In the block diagram, Enable goes to a single isolated block labelled "Enable Logic". In the application circuits, Enable goes to an external header. In the timing diagrams, the sequencing is shown between Enable, Vout, and PowerGood, but not Vreg. In the text, not even a single paragraph is devoted to Enable's function.For an essential (albeit trivial) signal, there's not much attention given to how it works.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 13, 2014, 07:32:40 pm
content: Quote from: alanambrose on August 13, 2014, 04:00:51 pmAs Long Asyou design the pads to stick out at least 0.5mm from the side of the package, DF/QFns aren't too bad, and are in some respects easier to rework than QFPs - no bent /lifted pins, and no solder wicking up between pins.I don't like the ones that need a die slug soldering down though as this severely limits space for routing tracks

author: coppice
author_rank: Super Contributor
timestamp: August 13, 2014, 07:47:50 pm
content: Quote from: mikeselectricstuff on August 13, 2014, 07:32:40 pmIf you ever worked with LCCs in the 80s you will realise that the die slug is critical for sustained mechanical strength over many temperature cycles with a QFN. For RF parts it is also critical for performance, but I believe its present on most parts for mechanical reasons.

author: Rufus
author_rank: Super Contributor
timestamp: August 13, 2014, 08:02:06 pm
content: Parts with shit datasheets -http://www.st.com/web/catalog/sense_power/FM89/SC444/PF250725for example.Has a nasty 3mm square LGA-16 package to boot.

author: qwaarjet
author_rank: Regular Contributor
timestamp: August 14, 2014, 02:04:44 am
content: LT3652 in 3X3 mm DFN pacakage

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 14, 2014, 02:05:27 am
content: Quote from: Gribo on August 13, 2014, 11:49:17 amSpecifically, the -5BS/BT? That looks terrible...Tim

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 14, 2014, 03:05:07 am
content: Quote from: coppice on August 13, 2014, 03:35:17 amOne of those ceramic or nichrome heating elements.

author: alanambrose
author_rank: Frequent Contributor
timestamp: August 14, 2014, 04:28:46 pm
content: My pet hates right now are diodes that don't have cathode markings, chips where the pin 1 orientation is markedon the bottom of the chip, datasheets which show the pinoutlooking at the chip from below, molexput every component in the same parameterised drawingBS - only to be beaten by datasheets where it isn't possible to tell whether the pinout is shown from the top or the bottom. I'm getting a bit worked up now (!) - you must have touched a nerve...Alan

author: BravoV
author_rank: Super Contributor
timestamp: August 14, 2014, 04:33:18 pm
content: Quote from: alanambrose on August 14, 2014, 04:28:46 pmCurious which chip is that ?

author: c4757p
author_rank: Super Contributor
timestamp: August 14, 2014, 04:38:37 pm
content: Quote from: alanambrose on August 14, 2014, 04:28:46 pmThis is not uncommon with relays - and ought to be punishable by public flogging

author: Sigmoid
author_rank: Frequent Contributor
timestamp: August 14, 2014, 06:37:13 pm
content: Quote from: free_electron on August 12, 2014, 02:15:42 pmAw that was just mean.

author: tszaboo
author_rank: Super Contributor
timestamp: August 14, 2014, 08:30:59 pm
content: Quote from: alanambrose on August 14, 2014, 04:28:46 pmOh yes. Mr Smoke there you go, revision 2 here I come.I also dislike the SOIC, where the orientation is where the mold is thinner (becasue just printing a dot is so 20 century), but my favourite are the ICs where the datecode or some other BS is on the bottom.For the Infineon haters, I totally agree. I refuse to design with anything infineon which has more than 2 PN junction or three pin.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 14, 2014, 09:13:03 pm
content: Chip-like parts with clockwise pin numbering from the top-right.That was a Mini-Circuits part, years ago...

author: wraper
author_rank: Unknown
timestamp: August 14, 2014, 09:33:42 pm
content: Quote from: SirNick on August 13, 2014, 07:13:50 pmActually there is written quite enough. Part of it:QuoteIn the specs max EN voltage = VinAnd how do you imagine that EN would work at all if there is no high voltage on it. Voltage cannot appear on the output in principle with EN disabled.

author: SirNick
author_rank: Frequent Contributor
timestamp: August 14, 2014, 11:03:44 pm
content: Yes, the datasheet at least tells you the acceptable voltage range of En, and that it will disable the output. However, I don't follow how your quoted text defines the relationship between En and Vreg -- being the main point of my gripe. (To be clear, Vo != Vreg. They are two distinct regulators.)On one hand, you might assume Vreg will be disabled -- it's a regulator, and you might want to have control over whether it's enabled.On the other hand, you might assume Vreg will NOT be disabled -- it exists for control of the switching regulator, so it should be available to... control the regulator.It took a failed prototype to determine that Vreg is in fact disabled when Enable it de-asserted. No biggie, but that would have been nice to know before wasting ~$20 on a board and some parts, and a couple weeks for turnaround. In hindsight, I should've just broken out the pins so I didn't have to re-spin the board if I guessed wrong. C'est la vie.

author: wraper
author_rank: Unknown
timestamp: August 14, 2014, 11:26:02 pm
content: Now understood that you talked about separate regulator. The thing is, seems that is not intended to connect anything to it at all except capacitor and PG resistor. Basically it exists as separate pin only because of the capacitor.

author: David Hess
author_rank: Super Contributor
timestamp: August 15, 2014, 12:02:13 am
content: I dislike large lead count parts which do not come in PLCC (J-Lead) packages and anything smaller than small outline packages except for sot-23 style packages.I also dislike the 555 because it suffers from noise induced by cross conduction when switching.

author: alanambrose
author_rank: Frequent Contributor
timestamp: August 15, 2014, 03:42:33 pm
content: >>> Curious which chip is that ?The LT6017 in DFN - theoretically it should have top side marking but even under a microscope you can't see it so you have to look at the copper underneath - where there's a corner cut-off. One of the diodes I was talking about is the ZHCS400 which has BD written on it - B is the anode....A.

author: Odysseus
author_rank: Regular Contributor
timestamp: August 18, 2014, 07:20:42 am
content: When I add a 555 to my breadboard, I always do so begrudgingly. The active-low reset and VCC (often shorted) are at opposite corners, the control and ground (decoupling cap) are at opposite corners, and the trigger and threshold (often shorted) are on different sides. All this means I can never satisfy my desire to make very neat and compact breadboard layouts with a 555. I really wish there was a more breadboard friendly variant.

author: Psi
author_rank: Super Contributor
timestamp: August 18, 2014, 08:11:14 am
content: Quote from: Richard Head on August 12, 2014, 11:44:59 am+1

author: tszaboo
author_rank: Super Contributor
timestamp: August 18, 2014, 09:52:27 pm
content: Quote from: mojo-chan on August 18, 2014, 10:10:14 amI remember once working with an I2C LCD. It had a 16 bit register named as "contrast". After suffering for 2 days, I realised that this register has to be written with the correct value, and that is why nothing else seems to work. Yeah, why would be the reset value useful?So then I started randomly writing numbers to it... nothing. Finally I wrote a code, which incrementally wrote every single value to this 16 bit, and I was sitting there with a stopwatch in my hand to figure it out which value was almost good. Ther was about 30 or so values which made anything visible on the screen.Datasheet is useless chinglish.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 19, 2014, 01:05:58 am
content: Quote from: mojo-chan on August 18, 2014, 10:10:14 amThere isn't even a good hardware spec, I2C is too old to account for all the various voltages used these days so you need I2C level translators liberally spread around your design.

author: daqq
author_rank: Super Contributor
timestamp: August 19, 2014, 08:07:45 am
content: On one side I love STM32xxx processors for their rich features, on the other side I hate them for their pinout from hell - seriously, how can you distribute one ~16 signal interface over THREE sides of a 4 sided 100 pin mixed up pretty much with everything right around the analog pins? There's a fair amount of similar examples - the SDIO interface is on two sides with pins not next to each other... seriously... WTF?

author: Davesaudio
author_rank: Newbie
timestamp: August 19, 2014, 08:19:42 pm
content: Anything small (QFN etc) with a thermal pad

author: Gribo
author_rank: Frequent Contributor
timestamp: August 20, 2014, 05:34:28 am
content: Antennas from reputable manufacturer without at least one radiation pattern in their datasheet.

author: pyrohaz
author_rank: Regular Contributor
timestamp: August 20, 2014, 12:38:24 pm
content: Quote from: daqq on August 19, 2014, 08:07:45 am+1

author: Artraze
author_rank: Contributor
timestamp: August 20, 2014, 02:36:00 pm
content: Quote from: daqq on August 19, 2014, 08:07:45 amI second the sentiment, but will say it's a pretty common problem for the larger microcontrollers... A couple years ago I was working with the LPCxxxx (don't recall) and its external memory bus was almost literally every other pin around the QFP. It's pretty clear the when the manufacturers figure everyone is using a 4+ layer board and will just dump things on their own layer so the pinout isn't that vital. I've actually found the STM32 F0 and F1 to be not that bad, in terms of at least bunching the GPIO in groups of 8 and generally keeping alternate functions close. I've definitely seen much worse.That said, the STM32F030F4P6 is a chip I (love to) hate working with. It's an ARM in a TSSOP20 for ~$1 (esp via AliExpress). The problem: 9 of I/O are basically just GP and all the dedicated functions are grouped on the other 6. To add insult to injury, the bootloader ROM uses the only locations for I2C (and other funcs) for its UART, when the UART could be multiplexed on pins that have no other functions.And with that I will add a more general gripe: datasheets that advertise a lot of functionality without mentioning that not all of it is actually usable, either because of shared resources or because it's simply not present on some versions of the device.

author: SirNick
author_rank: Frequent Contributor
timestamp: August 20, 2014, 07:52:04 pm
content: Quote from: Artraze on August 20, 2014, 02:36:00 pmAgreed! I've been working with a few ICs lately that seem to be designed by people who enjoy making your life difficult. "Keep the Clk pin as far away as possible from analog signals and power planes." That would be the Clk pin between Vcc and A+? Got it. I'll try and steer clear of those twoadjacent pins, then.My previously griped TI switching regulator has this problem too. A much cleaner layout could've been achieved by juggling a few pins around.

author: Prizmatic
author_rank: Regular Contributor
timestamp: August 20, 2014, 10:48:59 pm
content: Toroid/binocular cores. I've noted the number of wire turns achieved before losing count is age related. 1,2,3,4,5,6.... 7,8,9...Balls!

author: microbug
author_rank: Frequent Contributor
timestamp: August 20, 2014, 11:16:11 pm
content: Tiny packages. I just added two ICs to my design which are only available in 1.5mm by 1.5mm WSON6 packages... (2xBQ29700)I haven't tried yet, but I'll probably inhale them before I can solder them.

author: nctnico
author_rank: Super Contributor
timestamp: August 20, 2014, 11:27:19 pm
content: Anything from Atmel. If their datasheet states in bold that a device runs from 3.3V it doesn't. It's more like 3.6V but that is only in the fine print.

author: Whales
author_rank: Super Contributor
timestamp: August 23, 2014, 11:39:53 pm
content: Quote from: nctnico on August 20, 2014, 11:27:19 pmIt can, but at degraded performance/clock?

author: nctnico
author_rank: Super Contributor
timestamp: August 24, 2014, 01:53:43 am
content: Quote from: Whales on August 23, 2014, 11:39:53 pmNot even that.

author: rob77
author_rank: Super Contributor
timestamp: August 24, 2014, 08:39:07 am
content: Quote from: nctnico on August 24, 2014, 01:53:43 amthe whole world is using atmel mcus at 3.3V running at reduced clock of 8 MHz or less... so think about it a bit

author: nctnico
author_rank: Super Contributor
timestamp: August 24, 2014, 09:56:34 am
content: Quote from: rob77 on August 24, 2014, 08:39:07 amYou should read more carefully. I wrote IF an Atmel datasheet says the lowest voltage is 3.3V then you shouldn't run the device at 3.3V or you will get burned sooner or later. It is an example of what you can encounter. Other manufacturers like NXP or TI are way more honest about their devices.

author: Alex30
author_rank: Regular Contributor
timestamp: August 24, 2014, 01:42:26 pm
content: That's interesting, I have always considered Atmel to be pretty good with their datasheets. Very descriptive if you read them thoroughly

author: David Hess
author_rank: Super Contributor
timestamp: August 24, 2014, 08:04:51 pm
content: I have avoided Atmel products in the past because of their poor datasheets. There are examples of even worse datasheets like from Allegro but that does not make Atmel's datasheets any better. TI's datasheets have gotten significantly worse over time but I have other reasons to avoid their parts.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 24, 2014, 11:13:02 pm
content: Atmel's documentation is usually clear, well formatted, sufficiently redundant (similar sections are often near copy-paste -- saves on time having to read through different sections), and well enough explain the code or registers or logic or whatever. They do lack in the implementation / detailed / analog department though. Example: the crappy ADC, BOD and POR in the ATmega series, and good luck finding any guaranteed min/max parameters on them (even a lot of typ are missing).Also the same sorts of things from Altera: good luck finding I/O pin characteristics, power supply specs (bypassing, current consumption..), that sort of thing.Tim

author: Alex30
author_rank: Regular Contributor
timestamp: August 26, 2014, 09:37:04 am
content: Quote from: T3sl4co1l on August 24, 2014, 11:13:02 pmYeah I agree with this. To be honest I suppose it depends on what your expectations are. Any consensus on what microcontroller manufacturer has more detailed datasheets than atmel?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 26, 2014, 02:15:06 pm
content: Not something I've researched thoroughly at all, but I've looked at an MSP430 or two and they seem to document things well enough. They're more powerful (16 bit, and usually faster and more features), and very popular, especially for low current consumption purposes (switchable low power clock options, low operating current in general).Anyone else?Tim

author: suicidaleggroll
author_rank: Super Contributor
timestamp: August 26, 2014, 02:37:11 pm
content: Quote from: T3sl4co1l on August 26, 2014, 02:15:06 pmI've used several MSP430s in different projects, and have never found anything significant lacking in TI's documentation. I find them quite pleasant to work with actually, provided they fit the requirements of the application. I have found a few small bugs in GRACE and of course I hate CCS with a passion and IAR isn't too far behind, but mspgcc works well.

author: made2hack
author_rank: Frequent Contributor
timestamp: August 26, 2014, 03:48:56 pm
content: BNC connectors. I loathe and love them at the same time.I love the fact that a well shielded SDI cable with BNC connectors will pass data at multi-gigabit speed. And I love the fact you twist to close it.I also loathe the fact you twist to close it, and that innevitably the connector on the 10000+ euro broadcast equipment feels incredibly flimsy. And that the slightest pull on the cable (because once you've connecte a bnc cable it can never be disconnected again by twisting... I'm looking at you Sony broadcasting equipment) feels as if the entre socket will pull out.

author: David Hess
author_rank: Super Contributor
timestamp: August 26, 2014, 05:17:07 pm
content: Quote from: trs80 on August 26, 2014, 03:48:56 pmTNC connectors have the solid feel that BNC connectors lack and are easier to use than SMA connectors in test equipment. Since TNC connectors are basically deprecated, I have grown to like SMB connectors in place of SMA connectors.One of the pleasant surprises I had when first working with GR-874 connectors is how solid they felt.

author: Pedram
author_rank: Regular Contributor
timestamp: August 26, 2014, 07:02:38 pm
content: fake/copy chips... i hate theme.

author: asgard
author_rank: Regular Contributor
timestamp: August 26, 2014, 08:58:45 pm
content: Quote from: AndyC_772 on August 12, 2014, 09:47:40 amI would agree wholeheartedly. QFN/DFN parts ( I have been using these for power MOSFET H-bridge drivers, lately) are horrible, when a hobbyist or small-timer like myself doesn't have an X-ray machine to check solder joints. Another horrible part is the SMD HDMI type A connectors I have been forced to use (from Molex). This thing puts all 19 pins in a single row adjacent to the main shell. The clearance is (almost) 0.5mm pitch, and therefore allows at max 6-8mil geometry to run the signals out. Try to hand assemble a board with one of these. Half the time the traces just evaporate before the solder joints are solidified. Next time I am going to try to get connectors from Adam, which just announced double offset rows of through pins on their connector.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 26, 2014, 11:28:59 pm
content: Quote from: asgard on August 26, 2014, 08:58:45 pmSolder iron about... 200C too hot???Tim

author: Gribo
author_rank: Frequent Contributor
timestamp: August 27, 2014, 04:11:25 am
content: Certain MGA series LNAs from Avago. Those are so sensitive to ESD, that a single wrong touch can fry them.

author: mrkev
author_rank: Regular Contributor
timestamp: August 27, 2014, 09:32:24 pm
content: There is nothing worse than fake parts from otherwise (at least we thought) genuine supplier.I've got parts for a school project (power fets) and they were OK, but the next batch were all fakes. Apparently some half-wit in their management thought that they will make more money if they buy from some chinese reseller and didn't even bothered to check if it meets the spec (and it didn't by far)...

author: asgard
author_rank: Regular Contributor
timestamp: August 28, 2014, 04:55:42 am
content: Quote from: T3sl4co1l on August 26, 2014, 11:28:59 pmSMD parts with hot air at 260C and at least 3" distance from the joint to the air tool tip. Effective temp at the copper is about 160C.The Adam parts will allow me to use 10mil traces from the pins, which should improve my disposition something wonderful.

author: poorchava
author_rank: Super Contributor
timestamp: August 28, 2014, 05:50:38 am
content: LCD drivers from Princeton Tech. The serial interface is a bad an sad joke. Total pain in the ass to write software for if that software is to be even remotely efficient. Same thing goed for other chinese products that have derial interfaces.

author: mikerj
author_rank: Super Contributor
timestamp: August 28, 2014, 09:01:55 am
content: Quote from: nctnico on August 24, 2014, 09:56:34 amWhich parts are you referring to specifically?

author: Circlotron
author_rank: Super Contributor
timestamp: August 28, 2014, 01:17:35 pm
content: I hate 27K resistors.Not a technical thing; more like a phobia :-P

author: nctnico
author_rank: Super Contributor
timestamp: August 28, 2014, 01:22:53 pm
content: Quote from: mikerj on August 28, 2014, 09:01:55 amAll digital chips from Atmel.

author: gxti
author_rank: Frequent Contributor
timestamp: August 28, 2014, 02:01:24 pm
content: Quote from: nctnico on August 28, 2014, 01:22:53 pmMany atmega parts go down to 2.7V or even lower. Be more specific.

author: nctnico
author_rank: Super Contributor
timestamp: August 28, 2014, 04:11:21 pm
content: Read more carefully what I wrote before: the 3.3V is just an example. If Atmel says a device will run at X volt then add approx 0.2V/0.3V to X to know at which voltage a device actually works reliable.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 28, 2014, 10:51:01 pm
content: Quote from: Circlotron on August 28, 2014, 01:17:35 pmI have a better one: 15 ohm resistors.Don't get it? Consider this... What color is a 1M resistor?Tim

author: David Hess
author_rank: Super Contributor
timestamp: September 03, 2014, 10:14:07 am
content: Quote from: mojo-chan on September 03, 2014, 08:41:39 amThe PIC instruction set architecture always reminds me of the 6502. A little bit of macro assembler messaging can improve the situation for those not comfortable with accumulator based ISAs.I might prefer Atmel's 8-bit ARV except for the previously mentioned problems with their documentation. I also have concerns about ongoing availability of Atmel parts.

author: coppice
author_rank: Super Contributor
timestamp: September 03, 2014, 10:32:31 am
content: Quote from: David Hess on September 03, 2014, 10:14:07 amWhy do you think a PIC is like a 6502? The PIC is Harvard like. The 6502 has a single address space architecture. I would have thought that gave them a very different feel.

author: djococaud
author_rank: Regular Contributor
timestamp: September 03, 2014, 11:10:35 am
content: Nothigh temperature wire you have to solder to a board...with insulation melting and retracting before you try to solder it !

author: David Hess
author_rank: Super Contributor
timestamp: September 03, 2014, 11:18:23 am
content: Quote from: coppice on September 03, 2014, 10:32:31 amThe separate address spaces hardly make a difference in most microcontroller applications where firmware will be fixed. The PIC still supports immediate operands even though immediate data gets pulled from the program address space instead of the unified address space.The programming environment for a processor with unified address space treats program address space and data address space separately most of the time anyway.

author: dannyf
author_rank: Super Contributor
timestamp: September 03, 2014, 11:21:13 am
content: QuoteEarly Luminary parts fall into that category. Thank God that TI bought them out.

author: dannyf
author_rank: Super Contributor
timestamp: September 03, 2014, 11:25:07 am
content: QuoteThe ADC modules in many Atmel chips are actually quite unique in terms of its differential inputs and user configurable gains. You rarely see that in low-priced chips, even among 32-bit chips.

author: jlmoon
author_rank: Unknown
timestamp: September 03, 2014, 06:19:20 pm
content: Quote from: T3sl4co1l on August 28, 2014, 10:51:01 pmThe last ones I saw didn't have any colors.. but they were RN 55C 's

author: Circlotron
author_rank: Super Contributor
timestamp: September 04, 2014, 05:22:37 am
content: Quote from: T3sl4co1l on August 28, 2014, 10:51:01 pmReminds me of when I was about 14, very early 70's before I had a scope, and I made this valve amplifier and used a 15 ohm resistor from grid to ground instead of a 1M. Eventually gave up on trying to make it work and pulled it all apart again. I think I actually nicked that resistor from the parts shop too.

author: hlokk
author_rank: Contributor
timestamp: September 04, 2014, 05:41:53 am
content: At the moment, panel meters. Trying to get them working when you have one supply can be a PITA especially when you order them, theres no info saying they can't have common ground (or worse, say they can, but turns out its only on a 20V range, not a 200mV range). Then if you get a common ground one you cant sense two parts in series on a loopI don't get why they cant just work properly as differential meters like they should.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 04, 2014, 06:46:38 am
content: Quote from: hlokk on September 04, 2014, 05:41:53 amBecause that would be hard!To be fair, good analog isolation is still a persistent challenge. Your best bet is usually to put in a completely isolated supply and let that be that.Tim

author: LektroiD
author_rank: Frequent Contributor
timestamp: September 04, 2014, 08:13:07 am
content: Never really got a problem with any parts as such, I find that part of electronics fun.I HATE wiring though...I've built amodular synthesizer, and I can tell you the absolute worst part of that is hand wiring all the sockets and switches & LEDs from the panels to the PCB.I've got the solid wire earth loop down to a fine art, but hate, HATE,HATEstranded wires.Ok, another pet hate is lead-free solder... The RoHS crew can go shove their tin-whiskers in their landfill (but that's another rant altogether)...

author: TMM
author_rank: Frequent Contributor
timestamp: September 04, 2014, 08:20:49 am
content: Quote from: void_error on August 13, 2014, 11:57:22 amHeh, definitely this.

author: Circlotron
author_rank: Super Contributor
timestamp: September 04, 2014, 01:34:46 pm
content: I hate working with Teflon insulated wire. It is sooo unbelievably hard to strip. You actually need a heated blade wire stripper to do the job properly. And it feels kind of greasy too.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 04, 2014, 04:20:10 pm
content: You can do a pretty darn good job with a sharp blade, scoring around -- trouble is, nick the wire and it's toast!Tim

author: coppice
author_rank: Super Contributor
timestamp: September 05, 2014, 03:51:48 am
content: Quote from: Circlotron on September 04, 2014, 01:34:46 pmWhat kind of temperature does your heated stripper run at if it melts Teflon? I hope its used with a really efficient extraction system, because things get pretty noxious when you get Teflon that hot.Teflon insulated wire strips very easily with the kind of stripper that brings together two semicircles of just the right size. I used to use tons of the stuff until it was banned from most applications because of the fire hazard. Are you using Teflon insulated wire for RF purposes?