MLCC Operating Temperature Range: 56 of 451 Datasheet Pages State One, 272,777 Part Numbers Have None, for United States Buyers

We parsed all 451 pages of the 28 Walsin datasheets we hold. 56 pages state an MLCC operating temperature range or a resistor one; 395 do not. No column in Walsin’s 203 export files carries temperature at all. For 272,777 of our 359,135 part numbers, no document we hold states it.

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Venatech Limited, an authorised Walsin distributor in Hong Kong, holds 28 Walsin Technology (Walsin) datasheets — 26 MLCC and 2 chip resistor, 451 pages — and all 203 of Walsin’s parametric export files. For this post we extracted the text of every one of those 451 pages ourselves and counted where an operating temperature range actually appears, then matched the result against the export line by line. Every part number below is real and present in our master set of 360,078 codes.

How many of the 451 datasheet pages state an operating temperature range?

56. We counted them page by page. 27 of the 28 documents state a range somewhere; 395 of 451 pages say nothing about it. The one document that never states a range is 00_MLCC_Application_Guide.pdf, 12 pages, whose page 3 opens a section headed “2-1 Operating temperature” and spends seven lines telling you to stay inside the specification without printing a single limit.

Document	Pages	Pages stating an operating temperature range	Where
00_MLCC_Full_Catalogue.pdf	65	20	one per series block
00_MLCC_Application_Guide.pdf	12	0	page 3 discusses it, states no limit
01_General_Purpose.pdf	21	2	page 4 electrical data, page 14 test table
11_Automotive_MT.pdf	29	1	page 3 only
15_High_Temperature_HT_150C.pdf	11	1	page 3 only
22_Feed_Through_FT.pdf	9	1	page 3, per part number
23_Mega_Cap_M_Series.pdf	15	1	page 9 only, inside a test table
Walsin_MR_Automotive_Thick_Film_Chip_Resistor.pdf	10	1	page 3
Walsin_WR_General_Purpose_Chip_Resistor.pdf	10	1	page 9
All 28 documents	451	56	27 of 28 documents

Two documents are worth naming. 23_Mega_Cap_M_Series.pdf is the only one of the 24 series approval sheets in which the words “Operating temperature” never appear in full — the range, −55 to +125 °C, is reachable only from page 9, written three times as a per-dielectric row inside a test table. And 22_Feed_Through_FT.pdf is the only document of 28 that states an operating temperature per part number rather than per series.

Which Walsin series has 26 part numbers with no operating temperature anywhere in the 451 pages?

The High Temperature HT series — the one series whose entire selling point is temperature. Page 3 of 15_High_Temperature_HT_150C.pdf carries a General Electrical Data table that names exactly one dielectric, X8G, and one range: −55 to +150 °C. We opened the HT export file. It holds 128 part numbers in two dielectrics: 102 X8G and 26 X8R.

We then searched all 451 pages for X8R. It appears on exactly one page — page 10 of that same HT file, in a construction table reading “X8G / X8R, CaZrO₃ based / BaTiO₃ based”. No capacitance range, no voltage list, no operating temperature. We have not seen this counted anywhere.

Part number	Series in the export	Dielectric in the export	Operating temperature in the 451 pages	Match / mismatch, export against datasheet
HT15G2R2B500	High Temperature HT	X8G	−55 to +150 °C, 15_High_Temperature_HT_150C.pdf p3	Match — the only dielectric the sheet tabulates
HT18R103K500	High Temperature HT	X8R	none stated on any of 451 pages	Mismatch — dielectric named once, in a construction table
HT31R104K500	High Temperature HT	X8R	none stated on any of 451 pages	Mismatch — same gap, 1206 case
1206F474M500	General Purpose	Y5V	none stated; Y5V is in the page-2 ordering key and absent from the page-4 electrical table	Mismatch
0201S153M4R0	General Purpose	X6S	−55 to +105 °C, 01_General_Purpose.pdf p4	Match
0805A475K500	General Purpose	X7S	−55 to +125 °C, same page, same table	Match
MT15G180J500	Automotive MT	X8G	−55 to +150 °C, 11_Automotive_MT.pdf p3	Match
SH55T225K251	Soft Termination SH	X7T	−55 to +125 °C, 19_Soft_Term_SH.pdf p3	Match
FT15X435M4R0	Feed Through FT	X5R	−55 to 85 °C, 22_Feed_Through_FT.pdf p3, stated per part number	Match — and 40 °C below every other FT part
WR06X4701FTL	WR general purpose chip resistor	not applicable	−55 to +155 °C, Walsin_WR_General_Purpose_Chip_Resistor.pdf p9	Match

The Y5V row is the second gap and it is in the biggest series we sell. Page 2 of 01_General_Purpose.pdf lists six dielectric order codes — N, B, F, X, S, A, where F = Y5V. The General Electrical Data table on page 4 lists five dielectrics and four operating temperature values, and Y5V is not one of the five. Two export rows carry it: 1206F474M500 and 1206F474Z500. The second one also carries tolerance code Z, −20/+80%, which is defined in 2 of the 28 documents — the full catalogue and 21_Low_Profile_TT.pdf — and not in the sheet that governs it.

Counted across the whole MLCC export: 29 of 24,026 rows carry a dielectric cell for which no operating temperature appears in the 451 pages — 26 X8R, 2 Y5V, and one row whose Dielectric cell reads 390.

Can I read a Walsin part’s operating temperature out of the parametric export?

Not directly, on any line. We opened all 203 export files and collected every column name: 96 distinct names across 203 files, and not one of them contains the string “temp”. Series is the only column present in all 203. There is no operating temperature column, no rated temperature column and no category temperature column anywhere in 390,477 rows.

For MLCC there is a workable indirect route, and it is worth stating precisely because it is the only one. 19 of the 203 files carry a Dielectric column, and operating temperature in these documents is a property of the dielectric, not of the series: X5R reads −55 to +85 °C, X6S −55 to +105 °C, NP0, X7R, X7S and X7T −55 to +125 °C, X8G −55 to +150 °C. So for 23,997 of the 24,026 MLCC rows you can recover the figure by reading the dielectric out of the export and the range out of the series sheet. For the other 29 you cannot, and for the seven non-MLCC families there is no dielectric column to read.

How many of the 359,135 part numbers have no operating temperature statement at all?

272,777 — 75.9% of the catalogue. We built the number from the two sides we hold. Six complete product lines have zero datasheets on file: thin film 93,914 part numbers, inductor 5,410, disc capacitor 929, RF 457, MOV 379 and antenna 44, which is 101,133 with no document and no column. Chip resistor adds the rest.

We parsed all 137 chip resistor export files and counted the part-number prefixes. There are 13 of them, and we hold a datasheet for 2.

Chip resistor prefix	Distinct part numbers	Datasheet we hold	Operating temperature available to us
WR	45,315	Walsin_WR_General_Purpose_Chip_Resistor.pdf	−55 to +155 °C, page 9
MR	17,442	Walsin_MR_Automotive_Thick_Film_Chip_Resistor.pdf	−55 to +155 °C, page 3
WF 76,554 · WK 31,805 · MF 14,791	123,150	none	none
SR 12,871 · WW 11,760 · SF 10,690	35,321	none	none
WA 5,887 · MK 3,030 · SA 2,772	11,689	none	none
MA 1,386 · WT 98	1,484	none	none

62,757 chip resistor part numbers sit behind a sheet. 171,644 do not. Add the 101,133 from the six zero-datasheet lines and you get 272,777 part numbers whose operating temperature we cannot state from a document — against 86,358 we can, which is 23,601 MLCC plus the 62,757 WR and MR resistors. We checked the SR series specifically, because an automotive buyer asks for it by name: the size codes SR04 and SR06 appear on zero of the 451 pages.

It reaches the stock list too. Of the 1,125 part numbers on our ready-stock snapshot as at 23 September 2026, 19 sit in a prefix for which we hold no datasheet — 8 WF, 5 MF, 3 WW, 1 WA and 2 chip inductors.

Why does searching these PDFs for degrees Celsius miss 99 of the 1,060 degree marks?

Because the 28 documents use three different degree characters, and we counted every one of them. U+00B0, the ordinary degree sign, appears 961 times in all 28 files. U+2103, the single-character ℃, appears 37 times in 10 files. And a private-use glyph at U+F0B0 — a Symbol-font degree mark that is not the degree sign at all — appears 62 times in 20 files.

That third one is not academic. It is the character used in the only operating temperature statement either chip resistor sheet contains. Page 3 of the MR sheet reads “Operation temperature −55 ~ +155” with a U+F0B0 before the C; page 9 of the WR sheet reads “Operating Temperature −55 ~ +155” the same way. Search either file for “°C” and you will not find its operating temperature. Note the wording too: MR says “Operation temperature”, WR says “Operating Temperature” — two spellings in a two-document set.

What should a United States buyer do before qualifying a part on temperature?

Three steps, and the first one takes about a minute per line. Read the dielectric code out of the part number, not out of a selector: on the General Purpose ordering key the second character is the dielectric, so X is X5R and caps your part at +85 °C while B is X7R at +125 °C in the same footprint and the same voltage. 751 of the 24,026 MLCC rows are X5R. That is a 40 °C ceiling difference the export will never show you.

1. Send us the part number and ask which document governs it. We hold 28 Walsin datasheets, 451 pages. Ask for the one covering your part number and it will be in your inbox, not in a brochure — and if the answer is that no page covers it, we will tell you that instead.
2. Cross the whole bill of materials in one pass. Paste up to 500 part numbers or drop your Excel or CSV into the free cross-reference tool, filter for high temperature or automotive grade, and read every stated difference rather than a claimed match.
3. Check what is physically in Hong Kong on ready stock before you commit a build slot — a dated snapshot as at 23 September 2026, not a live feed.

For what the HT series does and does not reach at 150 °C, see high temperature MLCC to 150 °C. For why the dielectric code is the field that decides this, see NP0 versus X7R versus X5R. The full line sits on the Walsin MLCC page.

The short version

56 of 451 pages state an operating temperature range, across 27 of 28 documents; 00_MLCC_Application_Guide.pdf discusses the subject on page 3 and prints no limit. No column in 203 export files carries temperature, so 272,777 of our 359,135 part numbers — 75.9% — have no operating temperature statement available to us at all. Inside MLCC, 29 of 24,026 rows carry a dielectric code the 451 pages never give a range for, 26 of them in the High Temperature series. Qualification stays with you, and so does the decision to accept an export figure in place of a page.

Send us the part numbers off your United States bill of materials and we will tell you, line by line, which Walsin document states the operating temperature and which figure came from the export with no page behind it — then what was physically in Hong Kong on 23 September 2026. And here is the question we would put back to you: if your selector shows an operating temperature for a Walsin part, where did it get it?

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Frequently asked questions

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