Chip Resistor Datasheet Revision ASC_WR_V24, SEP 2016: What a Ten-Year-Old Sheet Tells a United States Engineer, and What It Does Not

The chip resistor datasheet revision we hold for Walsin’s highest-volume resistor series is ASC_WR_V24, dated SEP 2016. It is ten years old, and it tabulates 8,032 of the 234,815 chip resistor part numbers in Walsin’s export. We hold no public URL for it. We would rather tell you that than quietly cite it.

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Venatech Limited, an authorised Walsin distributor in Hong Kong, holds 28 Walsin Technology (Walsin) datasheets, 451 pages, and all 203 of Walsin’s parametric export files. We parsed the 137 chip resistor files — 234,815 rows — against the ten pages of Walsin_WR_General_Purpose_Chip_Resistor.pdf and counted where the two agree and where they do not. Every part number below is real. Every count is of part numbers, not pieces.

How old is the Walsin WR chip resistor datasheet revision we hold?

Ten years and one month. We read the footer of all 451 pages we hold. The WR general purpose sheet is stamped ASC_WR_V24 SEP 2016 on every one of its ten pages. The MR automotive resistor sheet is ASC_MR_V13, March 2024. All 24 MLCC series sheets in the same library are dated 2026, between January and September. So the oldest and newest documents we hold are 121 months apart, and the oldest one governs the biggest series.

Document	Revision footer	Date	Age at 8 October 2026	Public URL
24 MLCC series sheets	name plus a month, no number	Jan to Sep 2026	1 to 9 months	Yes, in INDEX_MLCC_series.csv
Walsin_MR_Automotive_Thick_Film_Chip_Resistor.pdf	ASC_MR_V13	Mar 2024	31 months	None
Walsin_WR_General_Purpose_Chip_Resistor.pdf	ASC_WR_V24	SEP 2016	121 months	None

Two things follow from the “V24” in that code. There have been at least twenty-three earlier issues and we hold none of them; and there is no revision history anywhere in the sheet — we searched all 451 pages for “revision”, “revised”, “version” and “amend”, and all four return zero occurrences.

How many part numbers depend on ASC_WR_V24, and how do you count them yourself?

8,032, and the count takes about five minutes. We parsed all 137 files in _Walsin_Parts_Data/Walsin_ChipR_Product_Data/ — 234,815 rows. 45,315 of them carry a WR part-number prefix, and the WR prefix appears in no other series group in the entire chip resistor catalogue. Of those, 24,737 sit in a non-automotive WR general purpose series. ASC_WR_V24 tabulates four size codes. Only 8,032 of the 24,737 are in one of them — 3.4% of the whole chip resistor catalogue.

Repeat it in four steps:

1. Open the 27 files named Thick_Film_General_Purpose_*.xlsx. They hold 75,628 rows, 32.2% of the 234,815.
2. Filter the Series Group column to Thick Film General Purpose. Within it, 45,315 part numbers begin WR, 17,442 begin MR and 12,871 begin SR.
3. Drop every row whose Series contains “(Automotive)”. That leaves 24,737 rows, every one of them WR.
4. Keep only Size values beginning 1206, 0805, 0603 or 0402 — the four the sheet’s quick reference data lists. That is 8,032. The remaining 16,705 rows are outside the sheet entirely.

We have not seen this counted anywhere. It is the difference between “we have the datasheet” and “we have the datasheet for your part”.

Which WR size codes in the export are missing from the sheet?

Six of the ten. We read the size-code table on page 3 of ASC_WR_V24: it lists WR12 (1206), WR08 (0805), WR06 (0603) and WR04 (0402), and nothing else. The export carries ten distinct Size values on non-automotive WR rows; the six the sheet never names are 01005, 0201, 1210, 1218, 2010 and 2512, across 16,705 rows. Decode WR25X1002FTL with the sheet in front of you and the size code does not resolve.

Part number	Size in the export	Size code in ASC_WR_V24	Rated power in the export	TCR in the export	Match / mismatch vs ASC_WR_V24
WR12X1002FTL	1206 (3216)	WR12	1/4 W	≦±100	Match — size, power and TCR as tabulated
WR08X1002FTL	0805 (2012)	WR08	1/8 W	≦±100	Match on all three
WR06X1002FTL	0603 (1608)	WR06	1/10 W	≦±100	Match on all three
WR04X1002FTL	0402 (1005)	WR04	1/16 W	≦±100	Match on all three
WR02X1002FTL	0201 (0603)	Not in the sheet	1/20 W	≦±200	Mismatch — and ≦±200 is a grade the sheet never prints
WR01X1002FDL	01005 (0402)	Not in the sheet	1/32 W	≦±200	Mismatch — smallest part in the series, absent
WR18X1002FTL	1218 (3248)	Not in the sheet	1 W	≦±100	Mismatch — 1 W is four times the largest published rating
WR20X1002FTL	2010 (5025)	Not in the sheet	3/4 W	≦±100	Mismatch — no matching row in the sheet
WR20X1002FTR	2010 (5025)	Not in the sheet	1/2 W	≦±100	Mismatch — same stem as the row above; the final letter changes the rating
WR25X1002FTL	2512 (6432)	Not in the sheet	1 W	≦±100	Mismatch — largest part in the series, absent

We will not tell you a part is equivalent. We will show you where it differs — and on this series, six of the ten footprints differ from the governing document by not being in it.

Does the last letter of a WR part number mean what the sheet says it means?

Not reliably. Page 6 of ASC_WR_V24 gives the catalogue number as WR12 X 472_ J T L and labels the final field the termination code, with exactly one value: L = Sn base (lead free). We counted the last character of all 24,737 non-automotive WR part numbers: 14,627 end in L, 9,690 end in R and 420 end in N. So 10,110 of 24,737 rows — 40.9% — end in a code the sheet does not document at all.

It gets sharper. We stripped the final character and paired the L and R forms: 9,462 stems exist in both, and 4,362 of those pairs differ in rated power, in TCR, or in both — 1,710 differ in rated power, 3,050 in TCR. Meanwhile the Termination column reads Sn base (Lead free) on all 24,737 rows without exception. Whatever that final letter encodes, it is not the termination finish, and it changes electrical specification nearly half the time.

Two real pairs: WR20X1002FTL is 3/4 W and WR20X1002FTR is 1/2 W; WR10X1002FTL is 1/2 W and WR10X1002FTR is 1/3 W. Same size, same 10 kΩ, same ±1%, same TCR grade, one letter apart. If your tool treats that suffix as packaging noise and strips it, you have changed the part.

Where does the export disagree with the sheet outright?

In one place we can prove, and it is in a size the sheet does cover. The quick reference data on page 3 gives WR12’s maximum dissipation as 1/4 W at 70 °C ambient. We counted the 1206 rows in the non-automotive WR set: 2,218 of them, of which 140 are rated 1/2 W — twice the sheet’s figure, on a size code the sheet explicitly tabulates. One of them is WR12F1R00FTL FN, a 1.00 Ω ±1% part with a trailing suffix that appears nowhere in the sheet’s ordering key.

The TCR column tells the same story more broadly. ASC_WR_V24 publishes two grades: ≦±100 ppm/°C above 10 Ω, and −200 to +400 ppm/°C at 10 Ω and below. The export carries eight distinct TCR strings on non-automotive WR rows. 11,725 of 24,737 rows carry a notation the sheet never prints, including ≦±200 on 9,007 rows, ≦±300 on 551 and 0 ~ 600 on 276. Even inside the four sizes the sheet covers, 1,604 of the 8,032 rows carry a grade that is not in the document.

What does ASC_WR_V24 still tell you correctly?

More than its date suggests, as long as you stay inside the four sizes. We read all ten pages. For WR12, WR08, WR06 and WR04 it gives dimensions with tolerances to 0.05 mm, maximum operating voltage (200 V, 150 V, 75 V, 50 V) and maximum overload voltage (400 V, 300 V, 150 V, 100 V), climatic category 55/155/56, the full E96 three-digit marking code table, the RCWV formula, the derating curve, the soldering profile to J-STD-020D, and a two-year recommended shelf life.

Those are the fields least likely to have moved in ten years, and they are the ones a United States engineer needs for board design and incoming inspection. The fields that have clearly moved — size range, power range and the TCR grade set — must come from the export and be flagged. Use an old sheet for physics, not for catalogue scope.

What should a United States engineer do with a ten-year-old sheet?

Three steps, in this order, because each narrows the next. Of the 234,815 chip resistor part numbers we hold data for, 8,032 are covered by this sheet in both size and series; for the other 226,783 the export is your primary source and the sheet is context.

1. Check which side of the line your part is on. If the size code is WR12, WR08, WR06 or WR04, ASC_WR_V24 governs it and we will send you the PDF. If it is WR01, WR02, WR10, WR18, WR20 or WR25, the sheet does not describe your footprint and every figure comes from the export.
2. Cross the whole list in one pass. Paste up to 500 part numbers or drop your Excel or CSV into the free cross-reference tool. It is matched against Walsin’s published catalogue, returns candidates field by field, and states every difference from your original rather than hiding it. Filter by commercial or automotive grade, or for soft termination, high temperature, safety certified, high Q / low ESR or low profile.
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 covering 1,125 part numbers, not a live feed.

For the series at range level, see Walsin general purpose chip resistor range, and for the two families side by side, WR and MR series compared. The full range is on the Walsin chip resistor page.

The short version

The chip resistor datasheet revision we hold for Walsin’s WR general purpose series is ASC_WR_V24, SEP 2016 — 121 months old, against 24 MLCC sheets all dated 2026. It covers four size codes; the export carries ten. 8,032 of 234,815 chip resistor part numbers are inside it and 16,705 non-automotive WR rows are outside it. 10,110 of 24,737 rows end in a character the ordering key does not document, and 4,362 L-versus-R pairs differ in power or TCR while the Termination column reads identically on every row. 140 1206 rows are rated at twice the sheet’s published dissipation. We hold no public URL for the file. Qualification stays with you.

Send us the WR part numbers off your bill of materials and we will tell you, line by line, whether ASC_WR_V24 actually covers your footprint or whether the figure came from the export — then what was in Hong Kong on 23 September 2026. And if your tool strips the final letter off a Walsin resistor code, check those 4,362 pairs before your next build: which one of them is on your board?

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Frequently asked questions

<!– wp:rank-math/faq-block {"questions":[{"id":"faq-question-01","title":"What is the current Walsin WR chip resistor datasheet revision?","content":"The revision we hold is ASC_WR_V24, dated SEP 2016 and stamped on all ten of its pages. We do not know whether a later issue exists, because no document we hold says and we hold no public URL for the file. A current sheet and its link are on our request list to Walsin. The MR automotive sheet, by comparison, is ASC_MR_V13 from March 2024.”,”visible”:true},{“id”:”faq-question-02″,”title”:”How many Walsin chip resistor part numbers does ASC_WR_V24 cover?”,”content”:”8,032 of the 234,815 rows in Walsin’s chip resistor export, which is 3.4%. We parsed all 137 export files: 45,315 part numbers carry a WR prefix, 24,737 sit in a non-automotive WR general purpose series, and 8,032 of those are in one of the four size codes the sheet tabulates. The remaining 16,705 are outside it.”,”visible”:true},{“id”:”faq-question-03″,”title”:”Which WR size codes are missing from the datasheet?”,”content”:”Six of the ten in the export. The sheet lists WR12, WR08, WR06 and WR04 only. The export also carries 01005, 0201, 1210, 1218, 2010 and 2512 footprints — WR01X1002FDL, WR02X1002FTL, WR10X1002FTL, WR18X1002FTL, WR20X1002FTL and WR25X1002FTL are real examples, and none of their size codes resolves against page 3.”,”visible”:true},{“id”:”faq-question-04″,”title”:”What does the last letter of a Walsin WR part number mean?”,”content”:”The ordering key on page 6 documents one value for that field: L, tin-base lead-free termination. We counted all 24,737 non-automotive WR rows: 14,627 end in L, 9,690 end in R and 420 end in N. Of 9,462 L and R pairs sharing a stem, 4,362 differ in rated power or TCR, while the Termination column is identical on every row.”,”visible”:true},{“id”:”faq-question-05″,”title”:”Does Walsin’s export ever disagree with the WR datasheet?”,”content”:”Yes, in at least one provable place. Page 3 gives WR12 maximum dissipation as 1/4 W at 70 °C. We counted the 1206 rows: 140 of 2,218 are rated 1/2 W, including WR12F1R00FTL FN. On TCR, 11,725 of 24,737 rows carry a grade the sheet never prints. Both are on our request list to Walsin.”,”visible”:true},{“id”:”faq-question-06″,”title”:”Is a ten-year-old datasheet still usable?”,”content”:”For the right fields, yes. Dimensions, maximum operating and overload voltages, the E96 marking code table, the RCWV formula, the derating curve, the J-STD-020D soldering profile and the two-year shelf life are all in ASC_WR_V24 and are the fields least likely to have moved. Catalogue scope, power range and TCR grades must come from the export and be flagged.”,”visible”:true},{“id”:”faq-question-07″,”title”:”Why does Venatech publish the age of its own datasheet?”,”content”:”Because a buyer who finds out at qualification stage that the sheet is ten years old stops trusting everything else we sent. We hold 28 Walsin datasheets, 451 pages, and 26 of them have a public URL while two do not. Saying which is which costs us nothing and is checkable, which is the point.”,”visible”:true}],”listStyle”:””,”titleWrapper”:”h3″,”titleCssClasses”:””,”contentCssClasses”:””,”sizeSlug”:””} –>

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