Capacitors

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I will approach my capacitor selection similarly as to that for my Resistors—I will use a DigiKey parametric search.

I know that the primary application in this project will be for decoupling capacitors, and not much filtering/analogue. Consequently, I expect that my requirements are fairly relaxed, as I do not require extreme tolerances/stability/accuracy.

I would also expect the operating profile to be fairly low-calibre, as I do not expect this board to be used in extreme temperatures or otherwise demanding environments. With that said however, I will likely still need to consider operating temperatures due to the power dissipation of the components on the board.

With this considerations in mind, I will primarily focus on Class II MLCC capacitors, and specifically X7R type MLCCs. Due to the nature of my application, I will need to carefully consider capacitance degradation with respect to the applied DC bias voltage. For any filters/oscillator load capacitances, I will look at Class I C0G or NP0 capacitors for their constant DC voltage and temperature response.

Unlike my search for Resistors however, in this case I will place less direct emphasis on a specific family of devices, in order to facilitate more application-specific decisions.

Applying a basic search filter to only parts that are:

1. surface mount,
2. in stock,
3. available as Cut Tape,
4. active product status, and
5. have a datasheet,
   I narrow down the product selection from over 800 thousand to 36 thousand.

Sorting by stock quantity in descending order, I see that the most stocked manufacturers are:

• Murata
• Samsung
• YAGEO
• KYOCERA AVX
• Walsin

I see that the YAGEO Commodity Multilayer Ceramic Capacitor series includes NP0, X7R, X5R, and Y5V type capacitors, such that I may just be able to stay within this one family. For purely aesthetic reasons, I also note that these YAGEO capacitors are the only black/grey devices compared to the typical brown/orange of the other manufacturers, which may look better on my black PCB, and also means that I can have all my resistors/capacitors from one manufacturer.

Looking at Samsung's line of [MLCCs](Multi-Layer Capacitors - Samsung Electro-Mechanics | DigiKey), I see that this series only includes Class II type capacitors, and no Class I offerings—unlike the YAGEO series—but does include capacitances up to µ, unlike the maximum capacitance of µfrom YAGEO—but I do not expect this to be a problem as I do not expect to need capacitances this high (at least from an MLCC).