CT is a packaging suffix, and Walsin Technology (Walsin) omits it from the MLCC
parametric export. So the part number you copy out of a parametric search is a
specification code, not an orderable part number. 0805X106K500 is the exported form.
0805X106K500CT is the orderable form. The two differ by two characters and by whether the
order resolves.
What is the CT suffix on a Walsin part number?
CT denotes the packaging in which the part ships. It sits at the end of the part number,
after the voltage code. Everything before it describes the component itself: case size,
dielectric, capacitance, tolerance and rated voltage. Everything from CT onward describes
how it arrives.
A Walsin MLCC part number reads left to right as a chain of coded fields. 0201B102K160
breaks down as case size 0201, dielectric code B for X7R, capacitance code 102 for
1000 pF, tolerance code K for ±10% and voltage code 160 for 16 Vdc. That is a complete
electrical description. It is not a complete order.
Why does the part number I searched not match the part number I order?
Because the parametric export and the ordering system carry different forms of the same
part. The export publishes the specification code. The order system expects the
specification code plus the packaging suffix. Nothing in the search result tells you a
suffix is missing, which is why this catches people who are doing everything else right.
Here are eight real parts exactly as they appear in Walsin’s General Purpose MLCC export.
Every one of them is a specification code with no packaging suffix attached.
| Exported part number | Series | Size | Dielectric | Capacitance | Tolerance | Rated voltage |
|---|---|---|---|---|---|---|
| 0201B102K160 | General Purpose Caps | 0201 | X7R | 1000 pF | ±10% | 16 Vdc |
| 0201B222J100 | General Purpose Caps | 0201 | X7R | 2200 pF | ±5% | 10 Vdc |
| 0201B222K100 | General Purpose Caps | 0201 | X7R | 2200 pF | ±10% | 10 Vdc |
| 0201B271K160 | General Purpose Caps | 0201 | X7R | 270 pF | ±10% | 16 Vdc |
| 0201B472J100 | General Purpose Caps | 0201 | X7R | 4700 pF | ±5% | 10 Vdc |
| 0201B472K100 | General Purpose Caps | 0201 | X7R | 4700 pF | ±10% | 10 Vdc |
| 0201S153M4R0 | General Purpose Caps | 0201 | X6S | 15 nF | ±20% | 4 Vdc |
| 0201S222M100 | General Purpose Caps | 0201 | X6S | 2200 pF | ±20% | 10 Vdc |
Source: Walsin product index — https://www.passivecomponent.com/products/ (product
index). Confirm the orderable form per part before raising a purchase order.
Note the two dielectric codes in that list. B is X7R and S is X6S, and 0201S153M4R0
is a 4 Vdc part where the voltage code reads 4R0 rather than a three-digit form. The
export is internally consistent on the specification. It is simply silent on packaging.
How do I confirm the orderable form of a Walsin part?
Read the ECD document URL. Walsin’s per-part environmental and compliance documents are
named after the orderable part number, so the suffix that the parametric table omits shows
up in the filename. That is the most reliable cross-check available from the public site.
Here is the comparison, using real MT-series rows. The part number column is what the
export gives you. The URL column is what the document filename reveals.
| Exported part number | ECD document URL | Match / mismatch between the two forms |
|---|---|---|
| MT15N0R5C500 | https://www.passivecomponent.com/wp-content/uploads/ecd/MT15N0R5C500CT-IN.pdf | match: series, case code, capacitance, tolerance and voltage codes all identical · mismatch: document filename carries CT, exported part number does not |
| MT15N100F250 | https://www.passivecomponent.com/wp-content/uploads/ecd/MT15N100F250CT-IN.pdf | match: full specification code identical · mismatch: CT suffix present only in the filename |
| MT15N100F500 | https://www.passivecomponent.com/wp-content/uploads/ecd/MT15N100F500CT-IN.pdf | match: full specification code identical · mismatch: CT suffix present only in the filename |
| MT15N100G500 | https://www.passivecomponent.com/wp-content/uploads/ecd/MT15N100G500CT-IN.pdf | match: full specification code identical · mismatch: CT suffix present only in the filename; tolerance code G differs from the F rows above |
| MT15N101F100 | https://www.passivecomponent.com/wp-content/uploads/ecd/MT15N101F100CT-IN.pdf | match: full specification code identical · mismatch: CT suffix present only in the filename; capacitance code 101 not 100 |
| MT15N100F100 | https://www.passivecomponent.com/wp-content/uploads/ecd/N.pdf | match: nothing confirmable · mismatch: the document URL is a single-character filename and does not carry a part number at all |
The pattern holds across the series: the document is named for the orderable part, and the
orderable part carries CT.
Is CT the only packaging suffix Walsin uses?
No. CT is the one you will meet most often on MLCC, but it is not universal across the
catalogue. Other suffixes appear on other product lines and on other packaging options. The
safe assumption is that a suffix exists and needs confirming, not that CT is always the
right answer.
We have seen ZT on a stocked safety capacitor line alongside CT on a neighbouring line
from the same series. Two parts, same series, same case, different packaging suffix. A
purchase order that copies the suffix across from the line above is a real failure mode and
it happens more than it should.
Confirm the suffix on every line. Do not pattern-match from a neighbour.
What else is missing from the export that a buyer needs?
Three fields, and they are the three a buyer looks for first. moq, spq and
lead_time_weeks are blank on every row of every product line in Walsin’s export. Not
sparsely populated. Blank. The Packing column is empty on all 24,026 MLCC rows, and
Termination is populated on only 1,106 of them.
So the public catalogue answers the engineering question completely and the sourcing
question not at all. You can determine capacitance, tolerance, voltage, dielectric and
dimensions from the parametric data with confidence. You cannot determine minimum order
quantity, standard pack quantity, packaging format or availability from it at all.
That is not a criticism of the export. It is a statement about what the export is for. It
does mean that any workflow which goes straight from a parametric search to a purchase
order has a gap in it, and the CT suffix is where that gap first becomes visible.
How does this break a BOM in practice?
Quietly, and late. The engineer selects 0805X106K500 from the search, puts it on the BOM,
and the design review passes because the specification is correct. Purchasing sends the
line out, the part number does not resolve, and the line comes back as not found — often
during a build window rather than during design.
The fix is trivial once you know: append the packaging suffix, confirm it per part, and the
line resolves. 0805X106K500 becomes 0805X106K500CT. The cost of not knowing is a build
delay on a part that was in stock the whole time.
Venatech Limited, an authorised Walsin distributor in Hong Kong, checks this on every line
we quote. Send the specification codes off your BOM and we will return the orderable forms
with the packaging suffix confirmed.
Frequently asked questions
Does the CT suffix change the electrical specification of the part?
No. Everything electrical is encoded before the suffix: case size, dielectric, capacitance, tolerance and rated voltage. CT describes how the part is packaged for shipment. The die inside 0805X106K500CT is described entirely by 0805X106K500.
Can I just add CT to every Walsin part number I have?
No, and that is the trap. CT is common on MLCC but it is not the only packaging suffix in the catalogue. We have seen ZT on a stocked safety capacitor line from a series whose neighbouring line carries CT. Confirm the suffix per part rather than applying one globally.
Why does Walsin’s export leave the suffix off?
The parametric export is built to answer selection questions, not ordering questions. It publishes the specification code because that is what a design engineer filters on. The same export leaves moq, spq and lead_time_weeks blank on every row, which is consistent with that purpose.
How do I find the ECD document for a specific part?
Walsin publishes per-part ECD documents whose filenames carry the orderable part number, such as MT15N0R5C500CT-IN.pdf. Reaching them from a parametric row means following the document link on that row. Two rows we checked point at a truncated N.pdf filename, so the method is not universal.
Is the CT suffix included in the part number I should put on my BOM?
Yes, if your BOM is the document purchasing works from. Put the full orderable part number including the packaging suffix on the buying BOM. Keep the specification code in the engineering notes if it helps you trace the selection back to the parametric search.
Does this apply to Walsin chip resistors as well as MLCC?
Chip resistor part numbers carry their own suffix conventions — stocked lines such as WF04H1202DTL and MF12E2200FTL both end in a suffix block. The specific CT observation in this article is drawn from the MLCC export. Treat the underlying rule as general: confirm the orderable form per line, per product family.
What should I send you to get the orderable part numbers?
The specification codes as they came out of the search, and the quantities you need. We will return the orderable form for each, with the packaging suffix confirmed, and flag any line where the public documentation does not let us verify it.
Next step
Send Venatech Limited the part numbers exactly as they came out of Walsin’s parametric
search and we will return the orderable form of each, with the packaging suffix confirmed
per line rather than assumed. Where the public documentation does not let us verify a
suffix, we will say so rather than guessing. That is a five-minute check on our side and a
build delay avoided on yours.
Send us your BOM → · Browse Walsin MLCC →
Related reading: How to read a Walsin MLCC part number ·
How to cross-reference an MLCC properly
Cross it yourself. The cross-reference tool takes a single part number or a whole BOM column and returns the Walsin candidates with every field that differs stated plainly — qualification stays with you. Ready stock shows what is held in Hong Kong today, with an RFQ against any line.