General Purpose MLCC Selection: 145 of 841 Capacitance-Voltage Cells Have Exactly One Part

General purpose MLCC selection is not as deep as 8,467 rows suggests. We built the full capacitance-by-voltage grid from Walsin’s export: 221 capacitance values by 11 voltages makes 2,431 possible positions, only 841 are populated, and 145 of those 841 have exactly one part number behind them.

Venatech Limited, an authorised Walsin distributor in Hong Kong, holds the full parametric export from Walsin Technology (Walsin). This post is measured from 07_General_Purpose.xlsx, 8,467 rows, with one row excluded because its Capacitance cell holds a datasheet URL rather than a value — a known defect on part 0201N0R1D250, already flagged elsewhere on this site. Every part number below is real, and every count is a count of part numbers, not pieces.

How big is the full capacitance-by-voltage grid for general purpose MLCC selection?

2,431 positions. We read every row’s Capacitance and Rated Voltage field in 07_General_Purpose.xlsx, converted both to a common unit, and counted 221 distinct capacitance values across 11 distinct rated voltages — 4, 6.3, 10, 16, 25, 35, 50, 100, 200, 250 and 630 Vdc. Multiply the two and a complete general purpose MLCC selection grid has 2,431 cells. That is the true size of the catalogue a buyer is choosing from, not the 8,466 usable rows in the export, because most capacitance values exist at more than one voltage and most rows share a cell with several other part numbers.

Two-thirds of the theoretical grid is simply not manufactured — no surprise, since not every capacitance makes sense at every voltage. The number worth sitting with is the other one: of the 841 cells that genuinely exist, one in six has no alternative part number behind it at all.

How many positions in that grid are covered at all?

841 of 2,431, or 34.6%. We grouped all 8,466 usable rows of 07_General_Purpose.xlsx by capacitance and voltage and counted distinct part numbers in each cell. The richest cell, 1,000 pF at 50 Vdc, holds 44 distinct part numbers — the deepest single position in the entire general purpose range. The next three richest are 10,000 pF at 50 Vdc with 40, 100 pF at 50 Vdc with 39, and 220 pF at 50 Vdc with 37. All four richest cells sit at 50 Vdc, which carries 2,778 of the 8,466 rows, more than any other voltage.

How many positions have exactly one part number behind them?

145. We counted cells where the part-number count equals exactly one, across the whole 841-cell populated grid, and 145 of them qualify — a position a buyer can reach, but where Walsin’s general purpose range gives exactly one dielectric, one case size and one tolerance to get there. That is 17.2% of everything that is actually populated. A selection tool that reports “available” on these 145 positions is technically correct and is hiding that there is no second choice inside the series.

0805B225K350 is worth a second look on its own: 35 Vdc carries only 15 rows in the whole export, and this is the single cell above 1 µF at that voltage. If a design calls for 2.2 µF at 35 V in general purpose and this specific combination of case size, dielectric and tolerance does not fit, the next move is a different series or a different voltage, not a different general purpose part.

Where do the single-part positions cluster?

Mostly at the voltage extremes and at the smallest capacitance values, not evenly across the grid. We counted the 145 single-part cells in 07_General_Purpose.xlsx by voltage:

50 Vdc carries both the richest cells and the most single-part cells, because it simply carries the most rows — 2,778 of 8,466. 200 Vdc, 250 Vdc and 630 Vdc are the opposite story: only 14 rows exist across all three voltages combined, so a request at any of them is close to a single-part request by default, and 10 of those 14 rows are themselves one of the 132 duplicated part numbers we measured separately in 07_General_Purpose.xlsx — the thin end of the voltage range and the duplicated end of the part-number list overlap more than either looks alone.

What does a single point of failure in this grid actually look like?

One footprint, one dielectric, one tolerance, and no second supplier inside the series if any of those three do not fit. Take 0603N220J6R3 — 22 pF, 6.3 Vdc, NP0, ±5%, 0603. If a design needs 22 pF at 6.3 V and the 0603 footprint will not fit the layout, or NP0’s temperature coefficient is wrong for the application, general purpose has nothing else to offer at that exact capacitance and voltage. The reader’s next move is a different capacitance, a different voltage, or a different Walsin MLCC series entirely — not a second general purpose part.

Why does one cell hold 44 parts and the next hold one?

Because tolerance, dielectric and case size multiply inside a cell, and some combinations are manufactured far more ways than others. Walsin’s own general purpose datasheet, WTC_MLCC_General_Purpose.pdf per INDEX_MLCC_series.csv, states six dielectrics and nine case sizes for the series, but not every dielectric reaches every case size at every voltage, which is exactly why the grid built from 07_General_Purpose.xlsx is 34.6% populated rather than full. The 1,000 pF / 50 Vdc cell holds 44 part numbers because Walsin makes that exact value across several case sizes (0402 through 1206), at least two dielectrics, and several tolerance bands — NP0 and X7R both show up at this value. A cell like 0.1 pF / 6.3 Vdc exists in exactly one place because sub-picofarad NP0 values are only manufactured at the smallest case sizes and the lowest voltages, so the combination of “very small capacitance” and “very low voltage” collapses the options to one part before tolerance or case size even gets a chance to add variety.

What should a buyer do with a single-part position?

Check before committing a footprint, not after. A buyer who designs around 0201N0R1B6R3 or any of the other 144 single-part positions has, by definition, no second general purpose candidate if lead time, stock or qualification rules that part out later.

1. Cross your exact capacitance and voltage through the free cross-reference tool before locking a footprint. It decodes 18 manufacturers’ part numbers and matches against 800,000+ crossable Walsin part numbers, across all 16 MLCC series, not general purpose alone.
2. Check what is physically in Hong Kong on ready stock, a dated snapshot as at 23 September 2026 — a single-part position is exactly the one you want confirmed in stock before a production run.
3. Ask us for the adjacent cells. If your exact position is one of the 145, we can tell you the nearest capacitance and voltage values that carry more than one candidate, which is often the easier fix than qualifying a second source for the single part itself.

For the full range this grid is built from, see Walsin general purpose MLCC: the full range, sizes and dielectrics. For how capacitance behaves as case size changes, see MLCC capacitance by case size. The full range is on the Walsin MLCC page.

The short version

We built the full capacitance-by-voltage selection grid for Walsin’s general purpose MLCC: 221 capacitance values across 11 voltages, 2,431 possible positions. Only 841 are populated, and 145 of those 841 — 17.2% — have exactly one part number. The richest cell holds 44 candidates; 145 cells hold one. Single-part positions cluster at 50 Vdc by volume and at 200, 250 and 630 Vdc by scarcity, where only 14 rows exist in total. We have not seen this grid built or counted anywhere else, and it is the honest answer to how deep general purpose MLCC selection actually runs once you pick a specific capacitance and a specific voltage rather than asking about the series as a whole.

Send us your exact capacitance and voltage and we will tell you, before you commit a footprint, whether you are choosing from 44 parts or from one — and if it is one, what the nearest cell with a real second candidate looks like.

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