A proper MLCC cross-reference compares thirteen fields and reports every mismatch. Size,
dielectric, capacitance, tolerance and rated voltage are the obvious five. Length, width,
thickness, termination, packing and supplied quantity decide whether the part actually
builds. A cross-reference that returns one part number and the word “equivalent” has told
you nothing you can act on.
What does it mean to cross-reference an MLCC properly?
It means producing a table, not a part number. You state the target specification, you
state the candidate, and you mark each field as a match or a mismatch. The engineer then
decides which mismatches are acceptable on their design. The distributor does not get to
make that call, because the distributor does not know the circuit.
Venatech Limited, an authorised Walsin distributor in Hong Kong, works from the full
parametric data set for Walsin Technology (Walsin) MLCC — 24,026 rows across 16 named
series. That is enough to answer honestly, including when the honest answer is that nothing
matches.
Which fields must I compare, and in what order?
Compare in this order: size, dielectric, capacitance, rated voltage, tolerance, then length,
width and thickness, then termination, packing and supplied quantity. Size and dielectric
are hard constraints. Voltage can only go up. Tolerance can only go tighter. Dimensions
decide whether it fits the pad and the stack-up.
The full field list we work to, taken from our own data schema:
- Part Number
- Series
- Size
- Dielectric
- Capacitance
- Tolerance
- Rated Voltage
- L
- W
- T
- Termination
- Packing
- SPQ
Fields 1 to 10 come out of the parametric data. Fields 11 to 13 usually do not, and that is
covered below.
Why is “equivalent” the wrong word?
Because it hides the decision. Two parts with identical capacitance, tolerance and case
size can differ in rated voltage, thickness, dielectric class and termination system. Each
of those differences changes something the engineer signed off. “Equivalent” asserts that
none of them matters, without knowing the circuit.
Here is a live example. A BOM line calls for 1 µF, 0603, 25 Vdc. Across the whole Walsin
MLCC data set, three parts return on 1 µF in 0603. All three are 16 Vdc.
| Walsin part number | Series | Size | Dielectric | Capacitance | Tolerance | Rated voltage | L / W / T (mm) | Match / mismatch vs 1 µF 0603 25 Vdc target |
|---|---|---|---|---|---|---|---|---|
| MT18B105J160 | Automotive Caps Qualified to AEC-Q200 (MT series) | 0603 | X7R | 1 µF | ±5% | 16 Vdc | 1.60 +0.15/−0.10 / 0.80 +0.15/−0.10 / 0.80 +0.15/−0.10 | match: size, capacitance · mismatch: 16 Vdc not 25 Vdc, tolerance tighter at ±5% |
| MT18B105K160 | Automotive Caps Qualified to AEC-Q200 (MT series) | 0603 | X7R | 1 µF | ±10% | 16 Vdc | 1.60 +0.15/−0.10 / 0.80 +0.15/−0.10 / 0.80 +0.15/−0.10 | match: size, capacitance, tolerance · mismatch: 16 Vdc not 25 Vdc |
| MT18B105M160 | Automotive Caps Qualified to AEC-Q200 (MT series) | 0603 | X7R | 1 µF | ±20% | 16 Vdc | 1.60 +0.15/−0.10 / 0.80 +0.15/−0.10 / 0.80 +0.15/−0.10 | match: size, capacitance · mismatch: 16 Vdc not 25 Vdc, tolerance looser at ±20% |
Source: Walsin product index — https://www.passivecomponent.com/products/ (product
index). Confirm every field against the series datasheet before release.
The honest output is: no match on rated voltage. All three candidates are rated below the
target. If the working voltage on that node is genuinely 5 V and the 25 V call-out was
headroom for DC bias, a 16 V part may be acceptable — but that is an engineering decision,
made with the DC bias curve in front of you. If the node actually sees 18 V, none of these
parts is usable and the word “equivalent” would have caused a field failure.
What happens when the exact combination does not exist?
You say so. Take 0.1 µF in 0603 at 50 Vdc — one of the most common lines on any BOM. Across
the Walsin MLCC data set we hold, that exact combination of value, case size and voltage
returns zero parts. There is no candidate to table. The correct answer is that the
combination is not available and the line needs a different case size or a different
voltage.
Compare that with 10 µF in 0805. Querying at a 16 Vdc target returns 35 Walsin parts across
three series — General Purpose Caps, Low Profile Caps (TT series) and Soft Termination
Capacitors (SH series, Ag-poly) — spanning 4, 6.3, 10, 16, 25 and 50 Vdc, with ±5%, ±10%,
±20% and −20/+80% tolerances available.
| Walsin part number | Series | Dielectric | Capacitance | Tolerance | Rated voltage | Match / mismatch vs 10 µF 0805 16 Vdc target |
|---|---|---|---|---|---|---|
| 0805X106K160 | General Purpose Caps | X5R | 10 µF | ±10% | 16 Vdc | match: size, capacitance, tolerance, rated voltage, L/W/T at 2.00/1.25/1.25 ±0.20 · mismatch: none on the compared fields; confirm termination and packing |
| 0805X106K100 | General Purpose Caps | X5R | 10 µF | ±10% | 10 Vdc | match: size, capacitance, tolerance, dimensions · mismatch: 10 Vdc not 16 Vdc |
| 0805B106K100 | General Purpose Caps | X7R | 10 µF | ±10% | 10 Vdc | match: size, capacitance, tolerance, dimensions · mismatch: 10 Vdc not 16 Vdc, X7R not X5R (a higher temperature ceiling, but a different DC bias curve) |
| 0805X106K6R3 | General Purpose Caps | X5R | 10 µF | ±10% | 6.3 Vdc | match: size, capacitance, tolerance, dimensions · mismatch: 6.3 Vdc, well below the target |
| 0805X106M6R3 | General Purpose Caps | X5R | 10 µF | ±20% | 6.3 Vdc | match: size, capacitance, dimensions · mismatch: 6.3 Vdc, tolerance ±20% not ±10% |
| 0805B106M100 | General Purpose Caps | X7R | 10 µF | ±20% | 10 Vdc | match: size, capacitance, dimensions · mismatch: 10 Vdc, ±20% tolerance, X7R not X5R |
One of those six is a full match on the compared fields. The other five are not, and each
row says exactly why. That is the deliverable.
Which field do people miss most often?
Thickness. Length and width are fixed by the case size code, so 0805 is 0805 everywhere.
Thickness is not. It varies between series at identical L and W, and it is the field that
turns a paper match into a mechanical failure under a shield can or inside a card-edge
slot.
Check it every time. A 0603 part in one series and a 0603 part in another can share every
electrical field and still differ in T and in T tolerance. If your product has a height
budget, thickness is a hard constraint and belongs alongside voltage, not in an appendix.
Termination is the second most missed. Standard nickel-barrier termination and a soft
polymer termination behave differently under board flex. The SH series carries an Ag-poly
soft termination; General Purpose parts do not. A cross-reference that moves a line between
those two has changed the mechanical behaviour of the joint even when every electrical
field matches.
How do I handle a part my current supplier says is going away?
Work at series and family level, and confirm the status with the manufacturer or your
distributor for that brand. We do not hold any other manufacturer’s affected-part list, so
we will never tell you that a specific competitor part number has been discontinued. What
we can do is take the specification off your BOM line and tell you, field by field, what
Walsin offers against it.
That is the useful division of labour. Your incumbent supplier owns the truth about their
own lifecycle status. We own the truth about what exists in the Walsin catalogue. Put the
two together and you get a decision instead of a rumour.
Two things the parametric data will not tell you
Walsin’s parametric export carries a Termination value on only 1,106 of the 24,026 rows in
the combined MLCC export. The Packing and SPQ columns are empty on every row. So fields 11
to 13 of the comparison list cannot be answered from the public data at all. They have to
come from the series datasheet or from a distributor who has confirmed them.
Separately, 231 MLCC in the catalogue are marked “Customized product” and are held back
from general listing. If a value looks like it should exist and does not appear in a
search, it may be one of those rather than a genuine gap.
Frequently asked questions
Can I cross-reference on capacitance and case size alone?
No. Those two fields narrow the list; they do not select a part. Rated voltage, dielectric, tolerance and thickness all change behaviour at identical capacitance and case size. A 0805 10 µF search returns parts from 4 Vdc to 50 Vdc across three different series. Picking from that list without the voltage column is guessing.
Is a higher voltage rating always a safe substitution?
Usually, but not automatically. A higher-rated part in the same case size normally has less active volume, so its effective capacitance under DC bias can differ from the part you are replacing. Higher voltage rating is safe for the breakdown margin. It is not automatically safe for the capacitance you will actually get.
Is a tighter tolerance always a safe substitution?
For the electrical specification, yes. A ±5% part sits inside a ±10% window. For sourcing, it narrows your options unnecessarily. If the BOM says ±10%, ask for ±10% and let the tighter parts be candidates rather than requirements.
Why will you not just tell me the equivalent part?
Because there is almost never one. Of the three Walsin parts that return on 1 µF in 0603, all three are rated 16 Vdc against a 25 Vdc call-out. Calling any of them equivalent hides the one fact that decides whether the board works. We publish matches and mismatches so the engineer keeps the decision.
How do you handle a value that returns nothing?
We tell you it returns nothing. 0.1 µF in 0603 at 50 Vdc returns zero Walsin parts in our data set. The next step is to relax a constraint deliberately — a larger case size, a lower voltage with verified headroom — rather than to accept a near-miss presented as a match.
Does an AEC-Q200 part cross-reference to a commercial one?
In the safe direction, largely yes: a qualified part can usually go into a commercial design. The reverse does not hold. Walsin’s MT series is qualified to AEC-Q200 and the MG series covers similar ground without that certification. Moving from MT to MG loses the certification even when every parametric field matches.
What do you need from me to run a cross-reference?
The value, case size, rated voltage, tolerance, dielectric and any qualification requirement, plus your height budget if you have one. If you only have the incumbent part number, send that and we will work back to the specification from the public datasheet rather than assuming it.
Next step
Send your BOM to Venatech Limited and we will return a field-by-field comparison against
the Walsin catalogue — size, dielectric, capacitance, tolerance, rated voltage, L, W, T and
termination, with every mismatch marked and every line that returns nothing reported as
returning nothing. We will not use the word equivalent. We will show you exactly where each
candidate differs and leave the decision where it belongs.
Send us your BOM → · Browse Walsin MLCC →
Related reading: How to read a Walsin MLCC part number ·
NP0 vs X7R vs X5R: which MLCC dielectric
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.