We've put together some commonly asked questions to give you more information about the services and products we offer.
Coilcraft reel labels contain a manufacturing date code embedded in the first six characters of the "LOT CODE" field.
The date is in MMDDYY format. In the example below, the code 101314 = October 13, 2014.
While Coilcraft has discontinued a small number of series, we will, when feasible, continue to support existing customers with previous order history for this series. For many of these parts, we have developed a newer series that surpasses the performance of the discontinued part. If you search for the discontinued part on our site, you will be guided to the replacement part.
Coilcraft can notify your company when products that you purchase are changed (Product Change Notice) or discontinued (Product Discontinuation Notice). Sign up for PCN and PDN emails here.
The effects of ground plane proximity depend on inductor geometry and test frequency, along with substrate thickness and dielectric constant. In many cases, the effect is small, but it can be significant in very tight-tolerance applications. The interaction of the magnetic field of an inductor with a metal ground plane is a complicated 3D E/M problem that requires careful measurement or simulation under specific application conditions. For this reason, Coilcraft cannot quantify these effects in general.
Power inductors, except for our smallest series, are commonly marked with a three-digit code that corresponds to the three numbers that follow the dash in the part number. This code refers to the value in nanoHenries, where the first two digits are the value and the last digit is the multiplier (10^x) or number of zeroes that follow. Therefore, 103 would be 10 × 10^3 (or 10 followed by three zeroes), which equals 10,000 nH, equivalent to 10 µH. Other examples:
The reason that we don't specify power ratings for our inductors is that the more meaningful rating is the rms current rating. Inductor rms current ratings are derived by applying dc or low frequency ac current and measuring the resultant temperature rise. This allows for an accurate determination of temperature rise vs. rms current, which can easily be related to temperature rise vs. power loss: Power Loss = Irms2 × DCR.
In practice, inductor losses can include high-frequency core loss, skin effect and proximity effect, which can add to the temperature rise. While these losses are application-dependent and should be verified in situ, Coilcraft offers tools for predicting frequency effects. To estimate core loss, conductor loss, and temperature rise of our power inductors, use the Core & Winding Loss Calculator.
ESR vs. frequency for chip inductors can be graphed using the RF Inductor Comparison Tool.
|Current||Current and Temperature Ratings|
|Inductance||Testing Inductors at Application Frequencies, Calibration, Compensation and Correlation|
|Quality factor (Q)||Key Parameters for Selecting RF Inductors, Measuring Self Resonant Frequency,
Testing Inductors at Application Frequencies
|SRF||Measuring Self Resonant Frequency, Testing Inductors at Application Frequencies|
|Temperature||Current and Temperature Ratings|
|Voltage||Working Voltage Ratings Applied to Inductors|
Yes, we provide many web-based tools and application notes to help you select the correct part.
Design Support Tools page Quickly zero in on the optimal part with these easy-to-use tools.
RF inductor finder Find every RF inductor that meets your specific requirements.
Power inductor finder View a sortable list of products that fit your application.
Converter inductor selector Input your parameters and get detailed inductor specifications.
Flyback transformer selector View a structured list of Coilcraft off-the-shelf flyback transformers.
We also provide cross references to IC applications and competitor parts:
IC / Inductor matching tool Get a list of Coilcraft parts suitable for 1000s of IC reference designs.
Competitor cross-reference Find Coilcraft alternatives to other manufacturers’ part numbers.
Our Application Notes page contains valuable information for selecting the right component for many applications.
$5.00 per reel Cover tape extender (no empty pockets or trailer)
$25.00 per reel Leader and trailer added
Thermal resistance is not specified for Coilcraft inductors and transformers because they are mostly open-frame style and not solid, homogeneous bodies like molded IC packages. These body styles have a variety of thermal flow paths and multiple heat sources (winding and core), as opposed to an IC that may generate heat in a specific junction and conduct heat consistently throughout a solid body.
To calculate an approximate thermal resistance, divide the temperature rise due to Irms current (e.g., 40°C rise) by the power required to generate that rise (Power = DCR × Irms2) .
Rth (in °C/W) = 40°C ÷ (DCR × Irms2) where DCR is in Ohms and Irms is in Amps.