Electronic Components
Here are things you need to consider when researching electronic components:
- Can you actually get the part? from a distributor (more likely)? from the manufacturer (not as likely)?
- Will the distributor sell you just 1 or 2 of the part or do you have to buy in quantity?
Is in stock or will there be a lead time (which is just an estimate! You've been warned.)
- What is the physical package? DIP? Surface-mount? For hand-soldering, consider:
- DIP packages are easy. They come in 0.3" width (standard) and 0.6" width (big, wide packages).
- SOIC (small-outline integrated circuit) are surface-mount but are solderable with some care.
- PLCC (plastic leaded chip carrier) are surface-mount but can fit in a PLCC socket (expensive!) which are easily solderable.
SSOP/TSOP/TQFP are surface-mount packages that have a lead pitch (spacing between pins) that is too small for most students to solder. Stay away unless you are confident in your skills.
Here is a great site with pictures of lots of package types!
- Does the distributor have a minimum order quantity (usually $25 or so)? Even if they do, they will generally just tack on an extra fee (like $5 or so) for ordering below the minimum order quantity (it's probably better to just order more stuff than to pay the fee!)
- Are you getting a production part? Or has it been marked NRND ("not recommended for new designs"), "lifetime buy", or "end-of-life"?
- How much does it cost? Have you compared the cost of "expensive" items at multiple distributors? Are you paying for a product feature that you don't need, hence incurring unnecessary cost (gold plating? 1000V rating? 0.1% tolerance?)
Distributors
Digi-Key is a reliable, broad-coverage supplier with a very good search engine. Look here first.
Mouser is also a pretty good distributor -- look here second. They have some parts in common with Digi-Key but also distribute from other manufacturers, so you should check both Digi-Key and Mouser. Recently, they seem to be undercutting Digi-Key on prices for many common parts and are stocking some popular chips (like FTDI's USB interface chips) while Digi-Key doesn't. They also have smaller minimum buys for some parts (like resistors, capacitors, etc.) Their search engine isn't as good as Digi-Key's but is getting better.
Newark has some parts that Digi-Key and Mouser don't, but their search engine makes me lose a few hairs every time I (try to) use it.
Allied has a very large catalog, but sometimes has large-ish minimum orders and trouble with actually stocking items. Worth checking out.
Avnet is mostly a distributor for industry clients.
MCM is "an inone company", like Newark...I'm not sure what this means, but it looks like they have a wide variety of parts, including "hot deals", clearance specials, and an e-bay outlet.
Arrow is a distributor with a huge variety of parts, some of which are in stock! Seriously, Arrow is one of the "big boys" of distributors (lots of industrial accounts) that has recently switched to also selling to the low-volume market, so you can actually find parts there that you can buy in single quantities. A good place to check.
NuHorizons is another niche-manufacturer distributor (like Mouser) that is worth a look if you're not having luck finding a part.
Active is a Canadian distributor meaning you may get good deals based on the exchange rate (if you're not in Canada, of course)
onlinecomponents.com -- I don't know much about them
Master Distributors seems to specialize in interconnects, electromechanical, and passive components.
CableWholesale.com sells really cheap computer cables, along with power supplies, fans, power strips, and other miscellaneous consumer goods.
Radio Shack is well known, and I wouldn't recommend it for regular components as they tend to be overpriced. However, their web site has become very useful for finding out if a particular Radio Shack store has a component in stock. For those last minute component needs, being able to find the exact store where your part can be found is very useful. Arrive at the store with very specific part numbers as the salesperson probably won't be able to help.
Fry's Electronics sells mostly consumer electronics but also has some T&M equipment and other components.
Future Electronics is mostly an industry distributor.
Manufacturer web sites will often have a link to distributors that sell their parts. So if you find a great part but can't find it at any distributor, look on the manufacturer's web site for their distributors. Conversely, distributors have a line card which is the list of manufacturers they represent. You might want to check a distributor's line card before wasting time looking for a unique part.
Manufacturers will sometimes also sell you parts directly, but this is not common yet, and sometimes there are minimum buys, dodgy ordering processes, shipping delays, etc. The dedicated distributors (Digi-Key, Mouser, etc.) have got the ordering and delivery processes finely tuned. Sometimes, however, ordering directly from the manufacturer is the only way to get parts.
Free Samples
Some manufacturers are very good about sending free samples of parts to students. Texas Instruments and Maxim are two companies that have been very supportive of our students in the past, sometimes even sending free samples using next-day shipping. Read the fine-print carefully as there may be limitations on which parts can be ordered, lead times, number of samples allowed in a given time period, etc.
Please do not abuse the free sample system. Manufacturers send out free samples because it benefits them to have designers become familiar with their parts, so that eventually they'll order lots more of them. Since you probably won't be doing that, the least you can do is use the system ethically and respect the fact that free samples incur a real cost to the manufacturer:
- Do not order parts that you don't need
- Do not resell free samples
- Do not misrepresent yourself on the free sample order
- Do ensure that your actions reflect well on yourself and the university so that the manufacturers continue to support our students
Smaller Distributors
Some of the distributors below are surplus distributors. Surplus distributors buy excess inventory from companies and sell it for (usually) much less than new parts. There are some great finds out there if you take the time to look, but it's not a good idea to rely on surplus distributors for critical components because once the surplus runs out, the parts are gone.
Marlin P. Jones has a nice selection of motors, LCD's, and lots of other things.
All Electronics is a fairly broad-line surplus distributor with some pretty good prices.
Electronix Express has probably the lowest prices I've found so far (and they've finally added on-line ordering!) The selection is hit-and-miss, but there are some really good deals there.
Herbach & Rademan are a decent broad-line distributor.
Electronic Goldmine is another decent broad-line distributor.
Circuit Specialists is another decent broad-line distributor. They're a good place to go to for non-name-brand test equipment.
Jameco has many products...lots of people use Jameco but I've usually found equivalent stuff elsewhere for less.
eBay has a Business & Industrial > Electronic Components auction section. There are some really good finds in there but, well, it's an auction.
Hobby Engineering focuses on kits, sensors, etc. for mainly robotic applications, though not exclusively so.
Surplus Sales of Nebraska specializes in hard-to-find and obsolete parts. They have other interesting things, too, like Litz wire, high voltage anode cable, regular hookup wire, RF parts, pinball machine spare parts, knobs, etc.
Ocean State Electronics is another decent broad-line distributor.
Mendelson Electronics has a variety of things, including very cheap wire.
B.G. Micro has a variety of random parts. Probably not the first place to look (their catalog is a bit cheesy). Kinda looks like an on-line Radio Shack store.
Alltronics is not All Electronics but both are pretty similar.
Gateway Electronics has a fairly broad collection of stuff.
Hosfelt Electronics also has a variety of components.
HSC Electronic Supply is another distributor with a broad range of components.
Jaycar Electronics is an Australian distributor with a wide variety of components.
JDR Microdevices has mostly computer peripherals but also sells test equipment, cables, etc.
JK Electronics is an old-school distributor that's been around a long time but their web site is a bit tough to navigate.
Maplin Electronics is a UK distributor of mostly consumer electronics, but with some components as well.
Parts Express sells a lot of audio/AV components as well as general electronic components.
Quickar Electronics has a pretty rough web site but a broad range of components.
Skycraft Parts & Surplus has a large selection of surplus components.
Tri-State Electronics has a large array of components and supplies.
Electronics 123 sells components but also modules (camera modules, motor control, micro programming, etc.)
DesignNotes has a large variety of electronic kits, as well as random parts, components, test instruments, etc.
Specialty Distributors
EarthLCD has a very big selection of LCD displays, LCD graphic panels, etc.
411 Technology Systems also has LCD's, along with surplus sales of LCD's for very low prices.
LEDTRONICS, Inc. has a very wide selection of all sorts of LED's. They also seem to have a companion site SurplusLED.
Brigar Electronics has a relatively limited inventory.
Buy LEDs OnLine is a distributor for HB of China and has really good prices.
Surplus Traders deals in high-volume surplus items, both in selling and buying. I doubt you'd get a good deal on a single wall transformer (and they have a bazillion different ones to choose from) but probably a pretty good deal on 100. They will also accept "wanted" ads for components that you're looking for.
Search Engines
There are some search engines available that will search multiple distributors for a given part.
FindChips is the new kid on the block and works really well! No annoying registration or ads.
FreeTradeZone is a fairly good site but they always try to get you to buy from them first (they are also trying to be a distributor). Plus you have to set up an account, give them lots of personal info, etc.
QuestLink is another search engine.
Chip Directory is more of a hobbyist's site but is still useful for finding parts
SpecSearch is a relatively new search engine organized in a directory fashion (like Yahoo!).
Electronic Manufacturers
There are approximately one gazillion manufacturers of electronic and related components. Here are some of them.
Texas Instruments -- everything. 74XX devices, microcontrollers, memories, programmable logic, motor drivers, analog/linear, etc. Like I said: everything.
Microchip is probably most famous for their ["MicrochipPIC"] microcontrollers, but they also have MOSFET drivers, supervisory circuits, memory devices, and some other neat things (like the ultra-cheap-and-tiny MCP6001 op-amp, for example).
Atmel is probably most known for their ["AtmelAVR"] microcontrollers and programmable logic devices.
Linear Technology has lots of linear devices (op-amps, etc.), switching power supply controllers, etc. In an incredibly smart move, they have developed and released a free analog simulator tool called ["SwitcherCAD"] that is much better than PSpice. The smartness of the move comes in the fact that ["SwitcherCAD"] comes complete with Spice simulation models for many of their parts, meaning you can construct some very accurate simulations (as long as you use their parts!)
ON Semi, formerly Motorola, makes "jellybean" parts, interface logic, etc. Most ON Semi parts that I use tend to be discretes like diodes, TVS's, 7805 regulators, etc. as these are well stocked and inexpensive compared to competitors.
ST Microelectronics is also a good source for discretes, linear components, voltage regulators, motor drivers, etc.
Freescale, also formerly Motorola, is probably most useful to you now as the manufacturer of the ["68HC908"] series of microcontrollers but they have lots of other semiconductor products.
Maxim (also Dallas Semiconductor) makes lots of "neat" parts...things you wouldn't have thought of. The venerable MAX232 interface chip is their invention. Just go look at what they've got. You might find yourself finding a solution to a problem you didn't know you had (for example, a D/A converter with built-in amplifier so you can actually drive some current out of this thing).
Analog Devices is the last word in really high quality analog devices (A/D's, D/A's, etc.) These are the guys you go to when quality really matters and price does not. Their on-line store may have unpopular parts (like extended-temperature devices) not stocked by any distributor.
Cypress makes lots of memory devices (SRAM's, FIFO's, etc.) and has recently become known for their EzUSB one-chip ["USB"] solutions, and their PSoC programmable-peripheral-block microcontrollers.
IDT is also known for memory devices.
Intersil (formerly Harris) has interface, power, linear, switches, etc.
AMP has an extremely wide variety of connectors and good mechanical drawings.
National Semiconductor has lots of linear devices.
NXP (formerly Philips) has discrete devices, linear devices, logic, programmable logic.
Fairchild has discrete components, logic devices (with nice datasheets!)
Micrel has linear, ["USB"], RF, Ethernet, and other neat things.
Other Manufacturers
Matrix Orbital makes a wide variety of interesting LCD, PLED, and VFD modules.
Batteries