Walsin Technology (Walsin) publishes roughly 1,433,800 part numbers if every line is
counted, and thin film resistors alone account for 1,169,070 of them — 82% of the whole
catalogue. Strip thin film out and the remaining seven product lines come to 264,958
parts: MLCC, chip resistor, inductor, disc and safety capacitor, RF, MOV and antenna.
How big is Walsin’s catalogue, really?
Big, and lopsided. Venatech Limited, an authorised Walsin distributor in Hong Kong,
extracted 264,958 parts across seven product lines into 93 files. Thin film was not
downloaded, because at 1,169,070 parts it dwarfs everything else and is not where sourcing
decisions are usually made.
Here is the extracted position, line by line.
| Product line | Files | Parts extracted |
|---|---|---|
| Chip resistor | 79 | 234,378 |
| MLCC | 8 | 23,360 |
| Inductor | 2 | 5,411 |
| Disc / safety capacitor | 1 | 929 |
| RF | 1 | 457 |
| MOV / varistor | 1 | 379 |
| Antenna | 1 | 44 |
| Total | 93 | 264,958 |
Chip resistor is 88% of that total. MLCC is 9%. Everything else together is under 3%. Any
statement about “the Walsin catalogue” that does not say which line it means is describing
chip resistors whether it intends to or not.
What is in the MLCC range, series by series?
Sixteen named series, totalling 24,026 rows in the combined export. General Purpose is the
largest at 8,467 parts. Middle to High Voltage (200 V to 4 kV) follows at 4,095 and
Microwave (RF series) at 3,615. The automotive, high-Q and soft-termination families sit
between 100 and 2,200 parts each.
| MLCC series | Parts |
|---|---|
| General Purpose Caps | 8,467 |
| Middle to High Voltage Caps (200 V–4 kV) | 4,095 |
| Microwave Caps (RF series) | 3,615 |
| Automotive Caps Qualified to AEC-Q200 (MT series) | 2,176 |
| High Q & Low ESR Caps (HH series) | 1,709 |
| Soft Termination Capacitors (SH series, Ag-poly) | 1,524 |
| Automotive Caps Without AEC-Q200 Certification (MG series) | 788 |
| Big sizes Caps 1825 2220 2225 | 501 |
| Ultra-small Caps (01R5 series) | 317 |
| Ultra Microwave Caps (UF series) | 285 |
| Safety Certificated Caps X1/Y2 (S2 series) | 173 |
| High Temperature Caps (HT series) | 128 |
| Automotive Soft term Caps Qualified to AEC-Q200 (ST series) | 118 |
| Soft Termination Capacitors (SG series, Cu-poly) | 65 |
| Low Profile Caps (TT series) | 57 |
| Feed Thru (3-termination) MLCC (FT series) | 8 |
Two observations worth carrying into a sourcing decision. The RF-oriented families — HH,
Microwave and Ultra Microwave — total 5,609 parts, which is unusually deep for a
manufacturer not primarily known for RF. And the Feed Thru FT series has eight parts total,
so if a design needs a three-terminal MLCC the available choice is very narrow.
What is in the chip resistor range?
234,378 parts across fourteen series groups. Thick Film General Purpose leads at 75,628.
High Precision Thick Film follows at 52,027 and Thick Film High Power at 40,255. The
specialised groups — anti-surge, low-ohm current sense, arrays, high voltage — each run
into the thousands or tens of thousands.
| Chip resistor series group | Parts |
|---|---|
| Thick Film General Purpose | 75,628 |
| High Precision Thick Film chip resistor | 52,027 |
| Thick Film High Power Chip Resistor | 40,255 |
| Thick Film High Voltage Chip Resistor | 20,244 |
| Thick Film Anti-Surge Chip Resistor | 17,180 |
| Thick Film Low Ohm Current Sense Chip-Resistor | 10,428 |
| Thick Film Chip Resistor Array | 7,250 |
| Thick Film Wide Terminal Power Chip-Resistor | 4,294 |
| Thick Film Trimmable Chip Resistor | 2,940 |
| Thick Film Chip Resistor Array (Anti-Sulfuration) | 2,772 |
| Metal Low Ohm Current Sense Chip-Resistor | 1,188 |
| Thick Film High Ohm Chip-Resistor (>10 MΩ) | 488 |
| Thick Film Chip Resistor Network, Convex Type | 98 |
| Chip Attenuator (Convex, Π type) | 23 |
The tail matters more than the head. If you need a chip attenuator, there are 23 parts in
the entire catalogue and the selection is effectively made for you. If you need a general
purpose thick film resistor, there are 75,628 and the selection problem is narrowing, not
finding.
Why does the public search tool show fewer parts than exist?
Because several series are not indexed. Six MLCC series return zero parts on Walsin’s own
search — VT, 0612, OP, S3, SG High Voltage and SH High Voltage. They exist as datasheets
only. Four further series appear on the marketing pages but are absent from the search tool
entirely: RH, RT, ME and Mega Cap.
That is ten series where a search returns nothing and the correct conclusion is not “these
parts do not exist”. For RH, RT, ME and Mega Cap there is no parametric data to download at
all, which means no filtering, no comparison table and no automated cross-reference. The
only route is the datasheet.
There is a second class of hidden parts. On chip resistors, the 1.5 W and 1/5 W power
ratings are missing from Walsin’s own filter dropdown. That makes 1,957 real parts
invisible to anyone selecting by power rating through the public tool. We hold those parts
in our extracted data.
And 231 MLCC are marked “Customized product” in the source data and held back from general
listing. If a value looks like it ought to exist and does not appear, it may be one of
those rather than a genuine gap.
Where do Walsin’s own numbers disagree with each other?
In three places we can document. The product counter includes the header row of the
underlying table on the MOV, antenna and RF pages, so each displayed figure reads one higher
than the number of real parts. The MLCC totals differ depending on which file you count.
And the parametric export fails above roughly 10,000 rows.
| Catalogue figure | What we counted | Match / mismatch |
|---|---|---|
| MOV / varistor | 379 parts extracted | match: the underlying data set is complete and downloadable · mismatch: the on-site counter includes the header row, so the displayed figure is one higher than the part count |
| Antenna | 44 parts extracted | match: complete and downloadable, ten series represented · mismatch: same header-row off-by-one on the counter |
| RF | 457 parts extracted | match: complete and downloadable across seven sub-families · mismatch: same header-row off-by-one on the counter |
| MLCC | 23,360 in the per-series files; 24,026 rows in the combined export | match: the same 16 series appear in both, and the series-level counts sum to 24,026 · mismatch: the two file sets differ by 666 rows and we have not reconciled the cause |
| Large chip resistor series | extracted in 79 separate files | match: the full data is obtainable · mismatch: the export fails above roughly 10,000 rows, so large series must be split by tolerance and then by rated power to extract at all |
The off-by-one is trivial in itself. It is worth knowing because it tells you the counter is
reporting table rows rather than parts, and that is a useful thing to know before you build
a sourcing decision on any manufacturer’s headline number.
Flagged for review: the MLCC per-series file set totals 23,360 parts while the
combined export totals 24,026 rows, and the published series breakdown sums to 24,026.
We have not established whether the 666-row difference is duplication, a series omitted
from the per-series set, or an extraction artefact. Do not publish either figure as the
definitive MLCC count until this is resolved.
What is missing documentation entirely?
208 inductors have no datasheet at all. They sit in the VEFL, WIP, SCM, SCA and BIH series.
The parametric data exists, so you can filter and compare them, but there is no document to
send to a design review and no drawing to check a footprint against.
That is a real constraint on a qualification programme. A part you cannot document is a
part you cannot easily release. If your process requires a datasheet on file for every line
on the BOM, check those five series before you design one in.
Two smaller documentation defects are worth recording. Disc capacitors are missing body
diameter, thickness and lead pitch in Walsin’s export; those dimensions exist only in the
datasheet drawing tables. And on the chip resistor side, ten parts carry a Termination value
that disagrees with the Tolerance value on the same row.
Frequently asked questions
How many parts does Walsin actually make?
Roughly 1,433,800 part numbers if the entire catalogue is counted, of which thin film
resistors are 1,169,070 — 82% of the total. The seven lines we hold extracted parametric
data for come to 264,958 parts. The distinction matters, because most sourcing questions
concern those seven lines rather than thin film.
Why is thin film so much larger than everything else?
Thin film resistors are specified across very fine resistance steps and tight tolerance
bands, so the number of distinct part numbers multiplies quickly. It is a property of how
the range is enumerated rather than a statement about manufacturing volume. We have not
downloaded the thin film data set for that reason.
If a series returns nothing on Walsin’s search, does it exist?
Often yes. Six MLCC series return zero parts on the public search — VT, 0612, OP, S3, SG
High Voltage and SH High Voltage — and exist as datasheets. Four more are on the marketing
pages but absent from the search tool entirely: RH, RT, ME and Mega Cap. Check the datasheet
before concluding a family does not exist.
Can I download the whole catalogue myself?
Not in one pass. Walsin’s parametric export fails above roughly 10,000 rows, so large series
have to be split by tolerance and then by rated power to extract at all. That is why our
chip resistor data arrived as 79 separate files. The full extracted set runs to 93 files
across seven product lines.
Which Walsin product line is deepest for RF work?
MLCC, unexpectedly. The High Q and Low ESR HH series (1,709 parts), Microwave RF series
(3,615) and Ultra Microwave UF series (285) total 5,609 RF-oriented capacitors. The
dedicated RF component line — baluns, filters, couplers, multiplexers — is much smaller at
457 parts.
Are there Walsin parts with no datasheet?
Yes. 208 inductors across the VEFL, WIP, SCM, SCA and BIH series have no datasheet. The
parametric data exists for them but there is no document to attach to a design review.
Check those five series specifically if your release process requires a datasheet on file.
How current is this catalogue picture?
The counts come from our own extraction of Walsin’s published data and are a point-in-time
position, not a live feed. Series composition changes slowly; individual part availability
changes constantly. Use these figures to understand the shape of the range, and ask us for
a current position on specific part numbers.
Next step
If you are trying to work out whether a part family exists at Walsin, ask us rather than
trusting a search result that returns nothing. Venatech Limited holds the extracted
parametric data for all 264,958 parts across the seven lines above, plus the datasheets for
the series that are not indexed. Send the specification and we will tell you what exists,
field by field, including when the honest answer is that nothing matches.
Send us your BOM → · Browse Walsin MLCC →
Related reading:
Walsin passive components held in Hong Kong stock ·
The CT suffix: turning a Walsin spec code into an orderable part number