Automotive-Grade Precision Passives for Austria and Switzerland: Where the TCR Shelf Stops

For precision instrumentation in Austria and Switzerland the automotive shelf stops at 50 ppm per degree Celsius. Every one of the 3,087 Walsin Technology (Walsin) chip resistor part numbers rated ≦±25 ppm/°C sits in a non-automotive series. The tightest temperature coefficient available inside any automotive series is ≦±50 ppm/°C, on 8,856 part numbers. You can have the automotive grade or the 25 ppm, not both.

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Venatech Limited, an authorised Walsin distributor in Hong Kong, holds all 137 of Walsin’s chip resistor export files — 234,815 rows — and the full 24,026-row MLCC export. This post measures what the automotive-designated shelf gives an industrial, instrumentation or medical designer who is buying it for its specification rather than for a car. Every part number below is real. Counts are of part numbers, not pieces.

Why would an Austrian or Swiss designer buy an automotive-grade part for a non-automotive build?

Because the qualification is a shorthand for a tested envelope, and industrial automation in Austria and medical instrumentation in Switzerland both buy envelopes. The automotive designation is the only machine-readable reliability marker in Walsin’s resistor data, and it carries across the catalogue: 102,995 of the 234,815 chip resistor rows sit in series whose name ends in “(Automotive)”.

That is the published figure and it is ours. What has not been measured before is where that shelf runs out when precision rather than temperature is the binding constraint. It runs out at the temperature coefficient, and it runs out sharply.

What is the tightest TCR Walsin offers, and is any of it automotive?

≦±25 ppm/°C, and none of it is automotive. We classified the TCR field on all 234,815 chip resistor rows. 3,087 carry ≦±25, and all 3,087 belong to one series — High Precision Thick Film chip resistor TC25 — which has no automotive sibling anywhere in the catalogue.

TCR grade	Total part numbers	In an automotive series	Match / mismatch for an automotive-designated buy
≦±25 ppm/°C	3,087	0	Mismatch — no automotive series reaches 25 ppm
≦±50 ppm/°C	22,995	8,856	Match — the automotive precision ceiling
≦±70 ppm/°C	438	226	Match
≦±100 ppm/°C	136,608	62,804	Match
≦±150 ppm/°C	3,811	2,949	Match
≦±200 ppm/°C	48,778	18,528	Match

The pattern holds in the other direction too. TC50 and TC100 both have automotive siblings — 8,680 and 3,995 part numbers — and TC25 does not. Within Walsin’s 52,027-row High Precision Thick Film group that leaves 12,675 automotive parts and 39,352 commercial ones, and the single tightest grade is entirely on the commercial side.

Two tolerance grades are also one-sided, in opposite directions. ±2% exists on 3,045 part numbers and every one is automotive. ±10% and ±20% exist on 2,780 part numbers each and not one is.

What does one 499 ohm precision line look like across all four TCR grades?

Six real part numbers, all 499 Ω, all ±0.1%, at 0603 and two other case sizes. The TCR grade is carried by a single character in position five of the part number: J is 25 ppm, K is 50 ppm, H is 100 ppm.

Part number	Series	Size	TCR	Rated power	Match / mismatch vs an automotive-designated 25 ppm requirement
WF06J4990BTL	TC25	0603	≦±25	1/10 W	Mismatch — meets the TCR, no automotive designation
WF06K4990BTL	TC50	0603	≦±50	1/10 W	Mismatch — neither 25 ppm nor automotive
WF06K4990BTLJ	TC50 (Automotive)	0603	≦±50	1/10 W	Mismatch — automotive, but 50 ppm
WF06H4990BTL	TC100	0603	≦±100	1/10 W	Mismatch — commercial, 100 ppm
WF04K4990BTLJ	TC50 (Automotive)	0402	≦±50	1/16 W	Mismatch — automotive at 0402, 50 ppm
WF12K4990BTL	TC50	1206	≦±50	1/4 W	Mismatch — larger case, commercial, 50 ppm

No row in that table satisfies both conditions, because no part in the catalogue does. Six part numbers share one resistance and one tolerance and differ in exactly two things: the TCR character and whether the packaging suffix carries the trailing J that marks the automotive variant. WF06K4990BTL and WF06K4990BTLJ are one character apart and sit in different series.

Note what that trailing J does to a reader. In position five, J means 25 ppm. At the end of the part number, J means automotive. The same letter carries two unrelated meanings in the same part number, and WF06J4990BTL — a 25 ppm commercial part — looks at a glance like the automotive one. For the TCR codes in full, see Tolerance, TCR and dielectric codes decoded.

Does the TC50 series name guarantee 50 ppm per degree Celsius?

Not in the commercial series, and yes in the automotive one. This is the inversion worth knowing.

Series	Part numbers	Rows at ≦±50	Rows at ≦±100	Match / mismatch vs the series name
TC50 (commercial)	14,797	13,703	1,094	Mismatch — 7.4% are looser than the name
TC50 (Automotive)	8,680	8,680	0	Match — every row holds ≦±50

All 1,094 looser rows carry the WK prefix; all 8,449 WF-prefix parts in the commercial TC50 series hold ≦±50. The automotive TC50 series is WF throughout, which is why its name is a safe filter and the commercial one’s is not. WK06K3R30DTL is one of the 1,094: a 0603, 3.30 Ω, ±0.5% part in a series named TC50 and exported at ≦±100 ppm/°C.

The TC100 automotive series behaves the same way in reverse. 1,145 of its 3,995 part numbers — 28.7% — carry a TCR other than ≦±100, split between ≦±200 on 570 rows and a bidirectional −200 to +400 ppm/°C band on 575. MF04H1R00DTL is a 0402, 1.00 Ω, ±0.5% part in that band.

Which case sizes does the precision range reach?

TC25 reaches three sizes. The automotive TC50 series reaches four, including one the TC25 does not.

Case size	TC25 parts	TC50 (Automotive) parts	Match / mismatch
0402 (1005)	0	1,828	Mismatch — automotive reaches a size TC25 does not
0603 (1608)	1,029	2,284	Match
0805 (2012)	1,029	2,284	Match
1206 (3216)	1,029	2,284	Match
1210 (3225)	0	0	Match — neither series reaches 1210

The resistance windows differ too. TC25 spans 470 Ω to 470 kΩ — three decades. TC50 (Automotive) spans 10 Ω to 1 MΩ — five decades. So the 25 ppm grade is narrower on both axes: fewer case sizes and a shorter resistance range. A Swiss instrumentation design that needs 25 ppm below 470 Ω or above 470 kΩ has nothing to select from in this catalogue, automotive or not. Background on where thin film takes over is in High precision thick film versus thin film precision.

Does the automotive capacitor shelf extend higher in voltage than the general purpose one?

Yes, and this is the clearer win for an Austrian industrial or Swiss medical design. We read the Rated Voltage field on all 8,467 rows of Walsin’s General Purpose Caps series and all 3,082 rows of the three automotive MLCC series.

General Purpose Caps hold eleven voltages and stop at 630 Vdc, with no 500 Vdc rating at all. The automotive series hold thirteen voltages and reach 3000 Vdc.

Rated voltage	General Purpose Caps	Automotive series (MT, MG, ST)	Match / mismatch
500 Vdc	0	45	Mismatch — the rating does not exist in General Purpose
630 Vdc	present	73	Match
1000 Vdc	0	32	Mismatch — above the General Purpose ceiling
1250 Vdc	0	2	Mismatch — two part numbers in the entire export
3000 Vdc	0	5	Mismatch — ST series only

157 of the 3,082 automotive rows are rated 500 Vdc or higher. MT31B102K501 is a 1206, 1000 pF, X7R, 500 Vdc part; MT32B103K102 is a 1210, 10 nF, X7R, 1000 Vdc part; MT31N102J631 is the 1206 NPO 1000 pF 630 Vdc part. For an isolation barrier or a creepage-constrained medical supply those ratings are not available from the general purpose series and have to come from either an automotive series or the dedicated 200 V to 4 kV range.

What does Venatech add for a buyer in Austria or Switzerland?

Everything ships from Hong Kong. Venatech Limited has no Austrian or Swiss entity, no European warehouse and no stock held anywhere in the European Union or Switzerland — the group’s entities are Hong Kong, Shenzhen, Singapore and Jiangmen, with Chengdu in preparation. A buyer in Vienna or Zurich is buying from Hong Kong, and should plan the lead time on that basis.

What that position does add is the measurement above and the document behind it. A manufacturer’s search page will return the 25 ppm parts and the automotive parts in the same result set and will not tell you the two sets never intersect. We will not tell you a part is equivalent. We will show you where it differs, field by field, and leave the qualification decision with you. The full range is on the Walsin chip resistor range page.

The short version

All 3,087 Walsin chip resistors at ≦±25 ppm/°C are commercial; the automotive precision ceiling is ≦±50 ppm/°C on 8,856 part numbers. The TC25 series has no automotive sibling, spans only three case sizes and only 470 Ω to 470 kΩ. The commercial TC50 series is looser than its own name on 1,094 of 14,797 rows while the automotive TC50 series is not on any of 8,680. And the automotive capacitor shelf carries five voltage ratings the General Purpose series does not, including the only two 1250 Vdc part numbers in the export.

Tell us which of the two constraints is hard — the 25 ppm or the automotive designation — and we will return the part numbers that meet it, the fields where the other constraint is not met, and the document that would have to be requested from Walsin to close the gap.

Faster than an email. The cross-reference tool takes a pasted part number or a spreadsheet and returns Walsin candidates field by field, with the differences named. Ready stock is a dated snapshot of what is physically in Hong Kong.

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Frequently asked questions

<!– wp:rank-math/faq-block {"questions":[{"id":"faq-question-01","title":"Does Walsin make a 25 ppm automotive chip resistor?","content":"No. All 3,087 part numbers at ≦±25 ppm/°C in Walsin's 234,815-row chip resistor export belong to the High Precision Thick Film TC25 series, which has no automotive variant. The tightest TCR in any automotive series is ≦±50 ppm/°C, on 8,856 part numbers.","visible":true},{"id":"faq-question-02","title":"Can an Austrian or Swiss industrial design use an AEC-Q200 part outside automotive?","content":"Yes, and the designation is the only machine-readable reliability marker in the data — 102,995 of 234,815 chip resistor part numbers carry \"(Automotive)\" in the series name. It is a tested envelope, not a restriction. Confirm the qualification report covers your exact part number before relying on it.","visible":true},{"id":"faq-question-03","title":"What resistance range does the Walsin TC25 series cover?","content":"470 Ω to 470 kΩ, at 0603, 0805 and 1206 only, with 1,029 part numbers at each case size. The automotive TC50 series is wider on both axes: 10 Ω to 1 MΩ across 0402, 0603, 0805 and 1206. There is no 25 ppm part below 470 Ω or above 470 kΩ in this catalogue.","visible":true},{"id":"faq-question-04","title":"Is every part in Walsin's TC50 series rated 50 ppm per degree Celsius?","content":"Not in the commercial series. 1,094 of its 14,797 part numbers are exported at ≦±100 ppm/°C and all 1,094 carry the WK prefix. The automotive TC50 series carries ≦±50 on all 8,680 of its rows, so its series name is a safe filter where the commercial one’s is not.”,”visible”:true},{“id”:”faq-question-05″,”title”:”What is the highest rated voltage in Walsin’s automotive MLCC range?”,”content”:”3000 Vdc, on five ST series part numbers. 157 of the 3,082 automotive rows are rated 500 Vdc or above. Walsin’s General Purpose Caps series stops at 630 Vdc and carries no 500 Vdc rating at all, so those five voltage steps exist only outside it.”,”visible”:true},{“id”:”faq-question-06″,”title”:”Which letter in a Walsin precision part number sets the TCR?”,”content”:”Position five. J is ≦±25 ppm/°C, K is ≦±50 and H is ≦±100. A trailing J at the end of the part number means something different — it marks the automotive variant. WF06J4990BTL is a 25 ppm commercial part and WF06K4990BTLJ is a 50 ppm automotive part.”,”visible”:true},{“id”:”faq-question-07″,”title”:”Does Venatech have an office in Austria or Switzerland?”,”content”:”No. Venatech Limited is in Hong Kong, with group entities in Shenzhen, Singapore and Jiangmen and Chengdu in preparation. There is no Austrian or Swiss entity and no European inventory. Everything ships from Hong Kong, on delivery terms agreed at quotation.”,”visible”:true}],”listStyle”:””,”titleWrapper”:”h3″,”titleCssClasses”:””,”contentCssClasses”:””,”sizeSlug”:””} –>

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Three ways to get this answered today

1. Cross a part, free. Paste up to 500 part numbers, or drop an Excel or CSV file, into the free cross-reference tool. It is matched against Walsin’s published catalogue and returns candidates field by field, with every difference from your original stated rather than hidden. Filter by commercial or automotive grade, or for soft termination, high temperature, safety certified, high Q / low ESR or low profile. There is no login and no charge.

2. Send the whole BOM. Upload a BOM and request a quote and we will come back line by line — including the lines we cannot help with, which is usually the more useful half of the answer.

3. Check the shelf before you commit. Ready stock shows what was physically in Hong Kong as at 23 September 2026. It is a dated snapshot, never a live feed, and quantities are never permanent.

Why take our word for any of this? Don’t — check it.

Venatech Limited (威納電子有限公司) is an authorised Walsin Technology distributor in Hong Kong. Confirm that with Walsin rather than with us. On the safety capacitor series we hold UL file E182369, which is searchable in UL’s own public database, together with TUV certificates R50381780 and R50195920 and CQC CQC20001280137 and CQC20001280136, against EN 60384-14:2023, IEC 60384-14:2023 and UL 60384-14. We hold 28 Walsin datasheets, 451 pages, and we will send the one covering your part number. Shipments arrive in original sealed Walsin packaging with lot and date-code traceability, and a certificate of conformity is available per shipment on request.

We will also tell you what we do not hold, which no competitor publishes. REACH, SVHC, conflict minerals, PFAS, China RoHS, ISO 9001, IATF 16949, PPAP, IMDS and a Declaration of Conformity appear nowhere in those 451 pages. You would rather hear that from us now than from your own supplier-approval team later. AEC-Q200 is compliant in Walsin’s own words and never certified, we hold no manufacturer’s end-of-life or allocation list for any brand, and qualification in your own circuit stays with you. We will not tell you a part is equivalent. We will show you where it differs.

Venatech Limited · Unit 207, 2/F, Sun Ling Plaza, 30 On Kui Street, Fanling, N.T., Hong Kong · (852) 2628 4777 · Hong Kong, Shenzhen, Singapore and Jiangmen, with Chengdu in preparation.