How to Find Alternates for MLCCs Not on Digi-Key's Site

[Kaleb_Kohlhase]

We are often asked for Multi-Layer Ceramic Capacitors (MLCC) that we do not currently list on our site. In many cases, we may carry the same manufacturer or may not, but in general, as long as you match the most important specifications, it won’t matter what manufacturer you get a comparable product from. For example, we don’t currently carry 04023D105KAT2A from AVX which is a manufacturer that we currently offer. Here is a pdf datasheet for relevant specifications: avxCap.pdf (439.4 KB)

Recommended Steps for Crossing MLCCs

1. Find Specifications:
The first step is to find a complete list of specifications if you prefer buying from Digi-Key. It does matter on an individual level at times which specifications matter based on the application the capacitor is used in, but you can always filter out most of these specifications on our site. The best thing to find is a datasheet as it will tell you what all the numbers and letters mean in a part number usually. That is why I put a file of the datasheet for the AVX part number above.
2. Determine Which Specifications Matter:
When we are asked for a generic cross for an MLCC and aren't given much more context, we assume the following: match every specification as close as we can. Here is a link to the category where these are found: https://www.digikey.com/short/z0ft91

We do have precedent on certain values, here is what I think matters:

• Capacitance has to be the same or within a small enough tolerance in the worst-case scenario. We avoid changing the Capacitance value as that may critically impact design behavior.
• Capacitance Tolerance has to be the same or less than the original value. In the worst-case scenario we may increase this value, but try to avoid this situation.
• Voltage has to be the same or greater than the original value. We do not go with less voltage in any case. This has a high probability of destroying the caps in most applications as voltage ratings are maximum.
• Temperature coefficient is a little more complicated as a lot of data is not publicly available on certain ratings when it comes to temperature response. Usually, we get requests with pretty common values like X7R, X5R, C0G (NP0), X5F, X6S, X7S, X7T, and more as these have pretty well-known responses. In most cases we try to keep this value the same, however, some coefficients do behave better over a large temperature range compared to other values. We highly encourage that you look for specific responses if possible and compare them to see what would be a decent pick if you can't match the original when there are no results.
• Operating Temperature should be the same or have a larger, similar range.
• Ratings (automotive and other important ratings) should be matched if this matters to the application, we often ignore this value if the original doesn't have specific ratings.
• Mounting type has to match no matter what.
• Package/Case has to match in most cases unless specified that the pads may accept a slightly different size. Some solder pads on some sizes may actually be cross-compatible depending on the solder pad tolerance on the printed circuit board.

All the other filters we tend to think are more insignificant than the ones mentioned above since MLCCs are so small and some specs just don’t matter to some applications. If they matter to you, the best practice is to match the same specification or get within an amount of tolerance you are okay with.

Apply the Filters One at a Time:

It is critical that you go through each filter category one at a time and select one or several values depending on the specification. If you try to apply all the filters at once, it is very likely you may get no results depending on the values you selected. We always click the "Apply Filters" button after selecting values in one category as some values in other filter categories may disappear as things become unavailable.

Example: Crossing 04023D105KAT2A

First here are the relevant specifications:

Specification Name	Value
Capacitance	1uF
Tolerance	+/-10%
Voltage	25V
Temperature Coefficient	X5R
Operating Temperature	-55C to 85C
Special Ratings	Standard(no special ratings)
Mounting Type	Surface Mount
Package/Case	0402
The first thing I do is apply the part status filter to Active and Not For New Designs (usually newest designs don’t matter too much and this produces more potential stock). Exclude “Not For New Designs” if you don’t want parts that may go obsolete at some point. I also make sure I select the checkboxes under the filters for Stocking Options: In Stock and Marketplace Product: Include.
The next thing I do is select the exact capacitance and apply filters.
The next step is to select 10% and below for tolerance and apply filters.
Then I select voltages from 25V up to the absolute maximum, even if it’s not possible for some voltages to be built into a 0402 package. Then I click apply filters.
If the original temperature coefficient is listed in the resulting filters, I apply that selection. If not, I would probably swap out X5R for X6S or any form of X7R. I apply filters again.
Here is where I would apply filters for package size if 0402 is on the list and apply filters.
The last thing I do is double-check the Operating Temperature to see if anything changed significantly. Since this hasn’t changed in this case, I’d consider all the part numbers below the filters as adequate replacements: https://www.digikey.com/short/z0f8b2 Some may even have special ratings such as AEC-Q200, an automotive specification. These won’t have a significant effect on most applications, so I include those in the search. At this point in the search, you can apply more filters if special specifications matter such as “Features” or “Thickness” or anything else on this picture: