What You Need to Know about Electronics Datasheets

When shopping for electronics pieces, it is vitally important that engineers and electricians know everything they can about a particular piece. After all, if the piece is not of the correct size, or shape, or if it weighs too much, it may not fit properly in whatever device they are designing. And size, shape, and weight are not the only characteristics to consider. Besides these, designers have to worry about the temperatures the device will endure, what solvents it can be exposed to, how much humidity it can take without being damaged, what resistance it might have, how much voltage it can take, and so on and so forth.

To find this information, designers read what are known as “datasheets.” Almost any electrical component will have a datasheet describing it in great detail, and explaining all of its various attributes and properties. Datasheets also include diagrams and pictures that help designers see exactly what an item looks like. Without datasheets, designing electrical circuits and devices would require an endless process of trial and error, until at last the designers found a configuration of electrical components that meshed seamlessly together. With datasheets—and especially now that datasheets are digitalized and searchable online—designers can say with some certainty that their chosen parts will work, even before a prototype is finished.

Who Creates Datasheets?

In the electronics component industry, a datasheet is effectively the “sales pitch” for an item or a device. By describing all of a product’s attributes, a datasheet lets potential buyers know whether it will work for them. If several products will work, the datasheet helps designers choose amongst them without needing to test them necessarily.

It’s for these reasons that electronics companies create their own datasheets and then make them freely available on their websites. In times past, the datasheets would have been mailed to electronics designers as a “catalog” of sorts, but the internet, email, and other means of electronic distribution have made that unnecessary. Now, designers can go to large databases that compile datasheets from hundreds of different companies, and there search datasheets for every product that is currently on the market. This has saved manufacturers money on the distribution of datasheets, and for designers, it greatly streamlines the process of searching through datasheets.

How Do Datasheets Specify Characteristics?

Datasheets specify the characteristics of a product in a number of different ways. In some cases, they show the shape and dimensions of a product using both tables that list various measurements of the product, and diagrams that indicate the lengths of its various sides and surfaces. For other information, like maximum ambient temperature or maximum voltage, the datasheet simply has rows that list this information.

In some cases, a datasheet will be published that describes several separate but closely related products. When this happens, there will be a table in the data sheet that lists all the areas in which the products differ. For instance, if the products have different resistances, then the table will have a column for resistance in which the resistance of each product is listed.

Typical Datasheet Information

Datasheets have information on a number of different characteristics that are relevant to electronic products and pieces. An overview of some of the most important of these characteristics is included below, along with brief comments on the importance of each characteristic.

Manufacturer’s Name

Every datasheet will include the name of the company that manufacturers the particular piece in question. Though this may seem like an obvious thing to include, it’s actually quite important, as some manufacturers put out similar products with similar or identical names, which nonetheless have somewhat different specifications.

Product Number

Electronic products are often known by a number as much as by their name. This is because names can become long and unwieldy, especially when they have to distinguish between many similar products that have nearly the same specifications, but differ in one small respect. Giving the product a number, and listing that number prominently on datasheets (and in the databases that carry these datasheets) makes it easier for designers to track down the product they are looking for.

Product Name

Besides the number, electronic products are also known by a name, though this typically doesn’t go beyond their generic name; for instance, “resistor,” “transistor,” “capacitor,” and so forth. Some companies do give their products more specific names, like “30 Volt DC Radial Leaded.” However, it is unusual for a company to name their electronic products with anything more than these generic terms that describe the product’s basic characteristics.

Available Package Formats

This describes the ways in which the product can be boxed and sent to the consumer. This is especially important for products that are ordered in quantities. It gives the buyer the option of ordering a box of 25, for instance, or a larger box that contains 100. Generally, a datasheet will list all the box sizes that are available, as well as mentioning whether odd quantities of the product can be shipped, as well.

Notable Device Properties

This is a section of the datasheet in which the manufacturer lists anything that might be unexpected about the product, anything that would explain an unusual price, or anything that would make it compatible or incompatible with other pieces and that a designer would absolutely need to know about. This is also a place to list the most salient qualities of the product. For instance, if it is a 30 volt battery, this is where that would be listed. Information that is basically standard, such as the temperature range in which the product can smoothly function, can be buried lower on the datasheet, but this exceptional information is pulled out and highlighted at the very top. The “notable device properties” section of a datasheet can be likened to a Cliffs Notes on the datasheet, and it is usually the section that designers will look to first when they are trying to pick out a product based on its datasheet descriptions.

Short Functional Description

The short functional description is where the manufacturer gives an overview of what the product does, usually in sentence form. This makes the datasheet more accessible to amateurs, who may not be sure exactly what they are looking at. It also assists those professionals who are branching out from their area of expertise and looking at electrical products they are not especially familiar with. This is commonly an area for manufacturers to “sell” their product and explain how it differs from similar products sold by competitors. For this reason, it is important to compare the claims made in the “short functional description” against the hard data provided in the remainder of the datasheet. The claims will not always match up to the product’s specifications.

Pin Connection Diagram

For keyed devices, a pin connection diagram is essential for showing which other components they can plug into, and which products they simply won’t be compatible with. The pin diagram will show the shape of the pins in the product’s plug. This can be compared to the socket diagram of other products the designer might plug it into, and in this way, the designers can judge the potential compatibility of the products.

Supply Voltage

Supply voltage specifies the parameters for the voltage that can be fed into a device. Typically there will be both a maximum and minimum voltage. When the maximum voltage is exceeded, it is possible that anything above that voltage would fry the internal components of the device, or cause it to slowly degrade. It is also possible that excessive voltage would cause the device to give off too much waste heat, which might lead to it overheating. Minimum voltage is usually related to the voltage drop off that occurs within the device. If the minimum voltage is not reached, then the drop off in voltage within the device would leave the current with zero voltage, and electrical flow through the circuit would be halted.

Power Consumption

These are the power requirements for a device—not the maximums and minimums, but the exact power amount it needs to function. Not all devices or components consume power, and so not all will have a power consumption number listed. However, when this number is listed, it is typically much more specific than supply voltage. Devices typically need a very exact amount of power, and anything more or less than that number will spell trouble.

Storage Temperature

This is essentially what it sounds like. Some electrical products are very sensitive to temperature, and must be kept at more or less ambient temperature at all times, or they will experience a decline in performance. However, most products simply have to be kept within a range of temperatures, and that range is generally quite wide. This is rarely a major concern for those purchasing parts, unless their device will frequently heat up the product while it is not in use.

Operating Temperature

This specifies several things. The first two are the maximum temperature at which the device can operate, and the minimum temperature at which it can. Designers have to be certain that the other operations within their device will not heat or cool the product beyond these parameters. Some electrical components are made in “heat resistant” or “cold resistant” formats, for designers making products that will be used in extreme environments.

The other thing operating temperature specifies is how hot or cold the product gets during operation. In particular, some products heat up very significantly while in use, which could cause problems for the pieces around them in a circuit or electrical device. Designers must be careful not to pick a product that gets too hot to be compatible with their project.

Dimensions

Almost any datasheet will come with a section that shows the dimensions of the product. Usually, this is done by means of a diagram, since that helps product designers envision exactly what they are buying. Dimensions are especially important when shopping for electrical components, because they often have to be crammed into confined spaces, or made to fit amongst many other small pieces. By looking at the product’s dimensions, designers can plan how they will integrate it into their physical design, and how it will sit alongside the other pieces of the product.

Contact Locations

Contact locations show where the product is to be plugged in, or where other products plug into it. This is important, since many products can have plugs in a range of different places or configurations. Sometimes product designers will have to search among otherwise identical products as they look for one that has the correct contact locations for their design. To accommodate such situations, manufacturers will make the same product in a few different shapes, each with its own set of contact locations.

Liability Disclaimer

This is where manufacturers explain under what circumstances or conditions their product should not be used. As one common example, they will point out that their product has some chance of failing, and that it should not be relied upon absolutely in cases of emergency, or when people’s wellbeing is on the line. As a matter of course, almost all datasheets will include a liability disclaimer. Parts meant to be used in hazardous situations or environments are apt to have longer or more involved disclaimers.

Ordering Codes

Similar to a product number, the ordering code is a shorthand way of referring to the product when purchasing it from the manufacturer. Ordering codes, however, should not be confused with product numbers. That is a common mistake that can hamper the process of finding a product that a designer is looking for.

Errata

Finally, this is the section of the datasheet in which the manufacturer notes how the current datasheet is different from earlier version. Mistakes and omissions on earlier datasheets are generally noted here, as are any addendums or clarifications that are needed on top of previous datasheets. Reading the errata section can be a quick way to see how a datasheet has been updated since the last time a designer read it.

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