MLCC Series Dielectric and Voltage Cells: 29 of 238 Hold One Part, and the ST Series Has Five of 11

MLCC series dielectric and voltage combinations are thin at the edges. We mapped 23,435 Walsin part numbers onto series, dielectric and rated voltage: 238 cells are filled and 29 of them hold exactly one part. The ST automotive soft termination series has 5 of 11 cells with one part each.

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Venatech Limited, an authorised Walsin distributor in Hong Kong, holds the combined MLCC export published by Walsin Technology (Walsin): 24,026 rows, 23,601 distinct part numbers. This post is written from that file, 00_ALL_MLCC_parts_combined.xlsx. We grouped every part number by series, dielectric and rated voltage and counted what sits in each cell. Every part number below is real. The question is one a second-source plan asks early: if you pick a series, a dielectric and a voltage, is there a second part to fall back on inside that series?

Two exclusions. The 165 safety-series (S2) part numbers are left out, because the export’s Rated Voltage on that series is the impulse voltage, not a working rating. One row whose Dielectric column reads 390 is also left out. That leaves 23,435 part numbers in 15 series.

How many series, dielectric and voltage cells does Walsin’s MLCC range fill?

238, and 29 of them hold exactly one part. We counted every combination of series, dielectric and rated voltage that has at least one part number. A further 12 cells hold two parts, so 41 of 238, 17.2 percent, hold two parts or fewer. The largest cell, general purpose NP0 at 50 V, holds 1,881. The five largest cells hold 5,524 parts between them; the 41 smallest hold 53.

Series	Part numbers	Cells filled	Cells with one part	Share of cells with one part	Match / mismatch against a second part in the cell
ST (automotive soft termination)	118	11	5	45.5%	Mismatch in 5 cells
TT (low profile)	56	9	4	44.4%	Mismatch in 4 cells
FT (feed-through)	8	3	1	33.3%	Mismatch in 1 cell
SG (soft termination, Cu-poly)	65	11	3	27.3%	Mismatch in 3 cells
Big sizes (1825 to 2225)	491	23	3	13.0%	Mismatch in 3 cells
MG (automotive, no AEC-Q200)	785	23	3	13.0%	Mismatch in 3 cells
01R5 (ultra-small)	317	10	1	10.0%	Mismatch in 1 cell
GP (general purpose)	8,330	41	4	9.8%	Mismatch in 4 cells
MVH (middle and high voltage)	3,871	24	2	8.3%	Mismatch in 2 cells
SH (soft termination, Ag-poly)	1,488	34	2	5.9%	Mismatch in 2 cells
MT (automotive AEC-Q200)	2,172	22	1	4.5%	Mismatch in 1 cell
HH, HT, RF, UF	1,706; 128; 3,615; 285	9; 3; 12; 3	0	0%	Match — no cell with one part

We have not seen this counted anywhere. The four series with the highest single-part share, ST, TT, FT and SG, hold 247 part numbers between them, 1.1 percent of the 23,435. They hold 13 of the 29 single-part cells. For the range-wide view by dielectric, see 65 of 154 dielectric and voltage cells hold a Walsin part.

Which series have the thinnest cells?

The small specialist series, and the ranking is the reverse of part count. We sorted the 15 series by share of cells with one part. ST leads at 5 of 11 (45.5 percent), TT follows at 4 of 9 (44.4 percent), then FT at 1 of 3, and SG at 3 of 11. The four series with the most parts, GP, MVH, RF and MT, sit at 9.8, 8.3, 0 and 4.5 percent.

A cell here ignores capacitance and case size. One part in a cell means one part in that series at that dielectric and that voltage across every case size and every capacitance value, so a second part with the same voltage and dielectric would have to be a different series. For what the soft termination family is and how its series differ, see soft termination MLCC: SH, SG, ST and VT.

What does the ST series actually offer in NP0?

Three parts, at three voltages, in two case sizes. We opened every ST row. The series holds 118 part numbers and exactly three of them are NP0: ST32N223J102 at 1000 V, ST32N103J12E at 1250 V and ST43N101K302 at 3000 V. Each is the only part in its cell. The first two are 1210 and the third is 1812.

ST NP0 cell	Parts	Real part	Size	Capacitance	Tolerance	Match / mismatch against an NP0 requirement at that voltage
1000 V	1	ST32N223J102	1210	22 nF	plus or minus 5%	Match if 22 nF fits; mismatch on any other value
1250 V	1	ST32N103J12E	1210	10 nF	plus or minus 5%	Match if 10 nF fits; mismatch on any other value
3000 V	1	ST43N101K302	1812	100 pF	plus or minus 10%	Match if 100 pF fits; mismatch on any other value
Your incumbent part	—	—	—	—	—	Fill in and compare field by field

In X7R the same series is wider, with 9 part numbers at 1000 V and 4 at 3000 V, but two X7R cells are single-part as well: ST32B106K100 at 10 V and ST31N103J631 at 630 V. A designer who wants a soft termination NP0 at an in-between voltage finds the series has none. The series naming and its AEC-Q200 position are covered in AEC-Q200 MLCC: MT vs MG.

Which single-part cells are the only one in the whole catalogue?

Six of the 29. We checked, for each single-part cell, whether any other series offers that dielectric and voltage. Six cells are the only part, from the only series, at that dielectric and voltage across all 23,435 part numbers. Four are in general purpose and two are in the middle and high voltage series.

Cell	Real part	Size	Capacitance	Match / mismatch against a second source
General purpose X5R at 100 V	0805A105M101	0805	1000 nF	Mismatch — no other X5R at 100 V
General purpose X6S at 50 V	0805S475K500	0805	4700 nF	Mismatch — no other X6S at 50 V
General purpose X6S at 100 V	1210S475K101	1210	4700 nF	Mismatch — no other X6S at 100 V
General purpose X7S at 50 V	0805A475K500	0805	4700 nF	Mismatch — no other X7S at 50 V
Middle and high voltage NP0 at 1300 V	1210N103J132	1210	10 nF	Mismatch — the only 1300 V part
Middle and high voltage X7R at 3500 V	1812B103K352	1812	10 nF	Mismatch — the only 3500 V part

The other 23 single-part cells have a second series at the same dielectric and voltage. They are single-part inside the series and not in the catalogue, so a cross within the range still exists. Among them are TT31X105K500 (low profile X5R at 50 V), SG31B102K202 (SG X7R at 2000 V), MG15N100J100 (MG NP0 at 10 V) and 2220N823J101 (big sizes NP0 at 100 V).

Where do the low-profile TT series cells run out?

At the edges of a 56-part series. The TT series holds 56 part numbers in 9 cells: X5R at 6.3, 10, 16, 25 and 50 V on 9, 14, 15, 12 and 1 part numbers, and X7R at 10, 16, 25 and 100 V on 1, 1, 2 and 1. Four cells are single-part: X5R at 50 V (TT31X105K500) and X7R at 10 V (TT21B475K100), 16 V (TT21B225K160) and 100 V (TT32B225K101).

The three X7R singles are 0805, 0805 and 1210. A low-profile design that needs 16 V X7R therefore has a series of one: 0805 and 2.2 uF. The case-size and height trade for the same series is in our UK height post; the point here is narrower. Inside TT, all four X7R cells hold one or two parts.

What should a BOM do when its cell holds one part?

Treat the cell as a single point and plan the second source before the design freezes. First, check whether another series offers the same dielectric and voltage; for 23 of the 29 single-part cells one does. Second, check whether your qualification rule allows the swap, for instance from a soft termination series to a standard one.

1. Look up the cell, not the part. Dielectric and voltage first, then series.
2. Paste the line into the free cross-reference tool and read the differences it states.
3. Check the shelf. Hong Kong stock is a dated snapshot, 1,125 part numbers as at 23 September 2026, on the ready-stock page.

The MLCC range page lists the series. We hold 28 Walsin datasheets, 451 pages; the cells above come from the export, not from a datasheet.

The short version

We grouped 23,435 Walsin MLCC by series, dielectric and voltage: 238 cells, 29 with one part, 41 with two or fewer. ST has 5 of 11 single-part cells and exactly three NP0 parts, at 1000, 1250 and 3000 V. TT has 4 of 9. Four small series hold 13 of the 29 single-part cells and 1.1 percent of the parts. Six cells are the only part in the catalogue at their dielectric and voltage. Confirm against both datasheets and qualify in your own circuit.

Send us the series, dielectric and voltage from your BOM and we will tell you how many parts sit behind each. And a question back: if the cell you approved holds one part, what is your plan for the day that part is not on the shelf?

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Frequently asked questions

<!– wp:rank-math/faq-block {"questions":[{"id":"faq-question-01","title":"How many MLCC cells hold only one Walsin part?","content":"Twenty-nine of 238. We grouped 23,435 part numbers by series, dielectric and rated voltage, excluding the safety series, whose voltage column is an impulse rating. A further 12 cells hold two parts, so 41 cells hold two or fewer.","visible":true},{"id":"faq-question-02","title":"Which Walsin MLCC series has the thinnest voltage and dielectric coverage?","content":"The ST automotive soft termination series, with 5 of its 11 cells holding one part, 45.5 percent. TT follows at 4 of 9. The two series hold 174 part numbers between them against 23,435 in the range as a whole, which is 0.7 percent.","visible":true},{"id":"faq-question-03","title":"Does Walsin offer a soft termination NP0 MLCC?","content":"In the ST series, three: ST32N223J102 at 1000 V, ST32N103J12E at 1250 V and ST43N101K302 at 3000 V. Each is the only part in its cell. The ST series holds 118 part numbers, so NP0 is 3 of 118. Confirm values against the datasheet.”,”visible”:true},{“id”:”faq-question-04″,”title”:”Is there more than one 100 V X5R MLCC from Walsin?”,”content”:”Not in the export we parsed. The only X5R at 100 V is 0805A105M101, a general purpose 1000 nF part at plus or minus 20 percent. It is one of six cells that are the only part from the only series at their dielectric and voltage. The others include X6S at 50 V and 100 V.”,”visible”:true},{“id”:”faq-question-05″,”title”:”Why count cells by series and not by dielectric?”,”content”:”Because a qualified series is what an approved vendor list usually names. A second part in a different series may need a separate approval. A cell with one part inside a series has no in-series fallback, even when another series offers the same dielectric and voltage, as 23 of the 29 do.”,”visible”:true},{“id”:”faq-question-06″,”title”:”Does a single-part cell mean the part is hard to get?”,”content”:”No. It means the export lists one part for that series, dielectric and voltage. It says nothing about availability and nothing about lead time, which the export does not carry. Check stock on the ready-stock page, a dated snapshot as at 23 September 2026.”,”visible”:true},{“id”:”faq-question-07″,”title”:”Does this count include the safety series?”,”content”:”No. The S2 series, 165 part numbers, is excluded because its Rated Voltage column holds the impulse voltage, 5000 or 6000 Vdc, not a working rating. The working ratings are in the datasheet. One row with 390 in the dielectric column is also excluded.”,”visible”:true}],”listStyle”:””,”titleWrapper”:”h3″,”titleCssClasses”:””,”contentCssClasses”:””,”sizeSlug”:””} –>

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