Walsin Technology (Walsin) covers 150 °C MLCC operation with one series: HT. Venatech
holds 128 HT parts, 102 of them X8G and 26 X8R, in 0402 through 1210, at 50 Vdc and 100 Vdc
only. Across the entire 24,026-part MLCC extract just 235 parts carry an X8 dielectric, which
is under 1% of the catalogue.
What makes an MLCC a 150 °C part?
The second character of the EIA dielectric code. X8 means an upper category temperature of
+150 °C, against +125 °C for X7 and +85 °C for X5. The third character sets the allowed
capacitance change over that range. X8G is Class I and holds a temperature coefficient;
X8R is Class II and holds a percentage window.
X8G in Walsin’s HT series is specified at within ±30 ppm/°C over −55 to +150 °C, with a
ceramic system the datasheet’s construction table describes as CaZrO3 based. It behaves like
an NP0 part that keeps going 25 °C higher.
X8R is the Class II option, BaTiO3 based in the same construction table. Class II buys
volumetric efficiency: far more capacitance in the same case size, at the cost of a
temperature window rather than a coefficient, plus DC bias loss and ageing. A 100 nF 1206
part cannot be built in Class I; a 10 pF 1206 part has no reason to be Class II.
How many Walsin MLCCs are actually rated to 150 °C?
235 of 24,026, or 0.98% of the extract Venatech Limited, an authorised Walsin distributor in
Hong Kong, holds. They sit in three series. HT carries 128 of them. The Microwave RF series
carries 104 X8G parts. The AEC-Q200 MT series carries three.
| Series | X8G parts held | X8R parts held | Case sizes held | What the series is for | Match / mismatch vs HT |
|---|---|---|---|---|---|
| High Temperature (HT) | 102 | 26 | 0402, 0603, 0805, 1206, 1210 | General 150 °C service | reference |
| Microwave RF | 104 | 0 | 0805 (101), 0603 (3) | Ultra-high-Q RF, 500 Vdc and above in this subset | match: X8G dielectric · mismatch: no X8R, RF-optimised, two case sizes |
| Automotive MT, AEC-Q200 | 3 | 0 | 0402 | AEC-Q200 qualified | match: X8G dielectric · mismatch: no X8R, one size, three parts, all 18 pF 50 Vdc |
Unique to Venatech’s data. The HT series is the only place X8R appears anywhere in
Walsin’s MLCC catalogue — 26 parts, all of them 50 Vdc and all ±10%. X8G appears three
times over: 102 parts in HT, 104 in the Microwave RF series and three in the AEC-Q200 MT
series. Measure the dielectric split before claiming 150 °C coverage. Counted from our
extract of Walsin’s own parametric export.
The three MT parts are MT15G180F500, MT15G180G500 and MT15G180J500, all 0402 X8G 18 pF
50 Vdc, differing only in tolerance. If a programme needs 150 °C and AEC-Q200 in one Walsin
part, that is the whole list. Everything else at 150 °C is HT, which is not AEC-Q200 qualified.
What is in the HT series?
128 parts across five case sizes: 0805 has 37, 1206 has 33, 0603 has 31, 1210 has 20 and
0402 has 7. The dielectric split is 102 X8G to 26 X8R. Capacitance runs from 1.0 pF in X8G
up to 100 nF in X8R. Rated voltage is 50 Vdc on 61 parts and 100 Vdc on 67.
Note what that leaves out: no 0201, no 1812 and nothing above 1210. It uses the standard
two-terminal footprints and the same reflow profile as the rest of the MLCC range.
The part number decodes like the rest of the catalogue. HT18G100J101 is HT series, size 18
for 0603, dielectric G for X8G, capacitance 100 for 10 pF, tolerance J for ±5%, rated voltage
101 for 100 Vdc. Add C for termination and T or G for reel size.
X8G or X8R: which HT part do I need?
X8G if you need stability, X8R if you need capacitance. X8G in HT reaches 15 nF at best and
covers both 50 Vdc and 100 Vdc. X8R reaches 100 nF but exists only at 50 Vdc, only at ±10%,
and only in 0603, 0805 and 1206.
| Field | HT32G153J500 (X8G) |
HT31R104K500 (X8R) |
Match / mismatch |
|---|---|---|---|
| Series | High Temperature HT | High Temperature HT | match |
| Case size | 1210 (3225) | 1206 (3216) | mismatch — different footprint |
| Dielectric class | X8G, Class I | X8R, Class II | mismatch |
| Capacitance | 15 nF | 100 nF | mismatch — 6.7× |
| Tolerance | ±5% | ±10% | mismatch |
| Rated voltage | 50 Vdc | 50 Vdc | match |
| L × W × T (mm) | 3.20 ±0.30 · 2.50 ±0.20 · 1.25 ±0.10 | 3.20 ±0.15 · 1.60 ±0.15 · 1.25 ±0.10 | match: nominal L, T · mismatch: W, and L tolerance |
| Thickness symbol | D | D | match — both reflow-only |
| Datasheet spec tables | Full: TCR, capacitance range, test limits | None found for X8R | mismatch — see flag below |
Both part numbers return a row in Walsin’s parametric export. Specifications from the
Walsin HT datasheet,
April 2026 revision.
0805B103K500 is a general purpose 0805 X7R 10 nF 50 Vdc, 0.80 mm thick. HT21R103K500 is the HT X8R 0805 10 nF 50 Vdc, 1.25 mm
thick. Same electrical line item, 0.45 mm taller, 25 °C more headroom, reflow-only.
Which rated voltages can I actually order?
Two: 50 Vdc and 100 Vdc. The HT datasheet’s capacitance range tables are laid out with
columns for 10, 16, 25, 50 and 100 VDC at 0603, 0805 and 1206, and 10, 16, 25 and 50 VDC at
0402 and 1210. Walsin’s parametric export returns nothing at 10, 16 or 25 Vdc.
| Rated voltage | Columns in the HT datasheet tables | Parts in Walsin’s export | Match / mismatch |
|---|---|---|---|
| 10 Vdc | 0402, 0603, 0805, 1206, 1210 | 0 | mismatch — tabulated, none returned |
| 16 Vdc | 0402, 0603, 0805, 1206, 1210 | 0 | mismatch — tabulated, none returned |
| 25 Vdc | 0402, 0603, 0805, 1206, 1210 | 0 | mismatch — tabulated, none returned |
| 50 Vdc | 0402, 0603, 0805, 1206, 1210 | 61 | match |
| 100 Vdc | 0603, 0805, 1206 | 67 | match |
Unique to Venatech’s data. Walsin’s HT datasheet tabulates five rated voltages from
10 VDC to 100 VDC across the capacitance range tables. Its parametric search returns parts
at two of them. Every one of the 128 HT parts we hold is 50 Vdc or 100 Vdc. Counted from
Walsin’s own export.
A 3.3 V rail does not need a 50 V part, and the 50 V part carries less capacitance per volume
than a 10 V part would.
Flagged for review. The 10 V, 16 V and 25 V HT columns in the datasheet may be
catalogue capability rather than stocked part numbers. Ask Walsin to confirm availability
in writing before a design commits to an HT part below 50 Vdc.
Which HT parts are reflow-only?
Any part whose thickness symbol is marked with a hash in the HT dimensions table. In
practice that is every symbol D and N part, plus 1210 symbol C. All 18 of the 0805 and
1206 X8R parts carry symbol D. So do eight X8G parts and all seven 0402 parts.
| Thickness symbol | X8G parts held | X8R parts held | Reflow-only per the HT datasheet |
|---|---|---|---|
| A (0805, 0.60 mm) | 17 | 0 | not marked |
| B (0805/1206, 0.80 mm) | 27 | 0 | not marked |
| C (1206/1210, 0.95 mm) | 20 | 0 | marked at 1210 |
| D (1.25 mm) | 8 | 18 | marked |
| N (0402, 0.50 mm) | 7 | 0 | marked |
| S (0603, 0.80 mm) | 20 | 8 | not marked |
| X (0603, 0.80 mm) | 3 | 0 | not marked |
The symbol is not in the part number, so check it against the datasheet dimensions table. The
HT sheet states the restriction per thickness symbol rather than per case size.
What does the HT datasheet not tell me?
Everything about X8R. The April 2026 HT datasheet we hold is titled for X8G dielectrics, and
its general electrical data, capacitance range tables, temperature coefficient clause, bending
test limits, resistance-to-soldering-heat limits and temperature cycling limits are all
written for X8G. X8R appears once, in the construction table.
That is a gap: 26 X8R parts exist in Walsin’s export and five sit above the capacitance
ceiling the same datasheet states. The stated HT range is 0.2 pF to 0.015 µF.
HT21R223K500 and HT31R223K500 are 22 nF, HT21R473K500 and HT31R473K500 are 47 nF, and
HT31R104K500 is 100 nF.
Unique to Venatech’s data. Five HT part numbers in Walsin’s parametric export exceed
the 0.015 µF capacitance ceiling printed in Walsin’s own HT datasheet, and all five are
X8R parts that the datasheet’s specification tables do not cover. The HT ordering key also
lists onlyGfor X8G — there is no published code for theRthat 26 real part numbers
use in that position. Measured from our extract.Flagged for review. Before quoting any HT X8R part, get written confirmation from
Walsin of the X8R temperature coefficient window, the bending test limit, the
resistance-to-soldering-heat limit and the capacitance ceiling. None of the four is in the
datasheet revision we hold. Also confirm whether the features bullet describing capacitance
stability “at 15%” up to 150 °C refers to X8R, since X8G in the same document is specified
at ±30 ppm/°C.
Two more gaps. The HT datasheet publishes no derating curve, so nothing tells you how much of
the 50 V or 100 V rating remains at 150 °C. And its applications list includes filter
circuitry “up to 125 °C”, below the series headline.
The eight checks before you commit an HT part
Eight checks, in order. The first three eliminate most HT selections, the middle three are
process constraints that will not show up until the line runs, and the last two are questions
only Walsin can answer.
- Confirm you need 150 °C, not 125 °C. X7R covers 125 °C with the whole catalogue behind it.
- Pick the class before the value. X8G for stability and low loss, X8R for capacitance.
- Check the voltage. HT ships at 50 Vdc and 100 Vdc in our extract, and X8R only at 50 Vdc.
- Check the tolerance. Every X8R part held is ±10%; X8G runs ±0.1 pF, ±5% and ±10%.
- Check the thickness symbol against the reflow-only marking before releasing the process.
- Confirm the height fits. X8R parts are 1.25 mm at 0805 and 1206, against 0.80 mm standard.
- If the programme is automotive, note that HT is not AEC-Q200 qualified.
- Get the X8R specification limits in writing, per the flag above.
FAQ
What does X8R mean on an MLCC?
X8R is an EIA Class II dielectric code. X sets the lower temperature limit at −55 °C, 8 sets
the upper limit at +150 °C, and R allows a ±15% capacitance change across that range. It is
the Class II counterpart to X8G, which holds a temperature coefficient instead of a
percentage window.
What is the difference between X8G and X8R?
Dielectric class. X8G is Class I, described in Walsin’s HT construction table as CaZrO3
based, and specified at within ±30 ppm/°C from −55 to +150 °C. X8R is Class II and BaTiO3
based, so it delivers far more capacitance per case size but carries DC bias loss, ageing
and a percentage tolerance window.
Which Walsin MLCC series has the highest temperature rating?
The HT High Temperature series is the general-purpose route, at 128 parts in Venatech’s
extract. Two other series carry X8G parts: the Microwave RF series with 104 and the AEC-Q200
MT series with three. In total 235 of the 24,026 Walsin MLCC parts we hold carry an X8
dielectric.
How much capacitance can I get in a high temperature Walsin MLCC?
100 nF, in HT31R104K500 — a 1206 X8R part at 50 Vdc and ±10%. X8G in the HT series tops
out at 15 nF. If a 150 °C design needs microfarads from Walsin, the catalogue does not
currently reach it and the requirement needs to be raised with Walsin directly.
Is the Walsin HT series AEC-Q200 qualified?
No. The HT datasheet is a standard approval sheet with no AEC-Q200 test table. Walsin’s
AEC-Q200 route to 150 °C is three 0402 X8G parts in the MT series, all 18 pF at 50 Vdc,
differing only in tolerance. For an automotive programme needing 150 °C and more than 18 pF,
raise it with Walsin.
What rated voltages does the HT series come in?
Two, in Walsin’s parametric export: 50 Vdc on 61 parts and 100 Vdc on 67. The datasheet’s
capacitance range tables also carry 10, 16 and 25 VDC columns, but the search tool returns
no parts at those voltages. Confirm availability with Walsin before designing in a low
voltage HT part.
Can I wave solder an HT capacitor?
Not if its thickness symbol carries the reflow-only marking, which covers every symbol D and
N part and 1210 symbol C. All 18 HT X8R parts at 0805 and 1206 are symbol D and 1.25 mm
thick, so they fall outside Walsin’s wave soldering recommendation of 0603, 0805 and 1206
below 1 mm.
Does an HT part use a different land pattern?
No. HT uses the standard two-terminal footprints for 0402, 0603, 0805, 1206 and 1210 in
Walsin’s MLCC application guide, and the same published reflow profile as the rest of the
MLCC range. The differences from a standard part are the dielectric, the thickness and the
reflow-only restriction, not the layout.
Next step
The HT range is small enough to check line by line, which is the fastest way to find out
whether a 150 °C requirement is buildable. Send the BOM lines that run hot and Venatech
Limited, an authorised Walsin distributor in Hong Kong, will return the HT part numbers
matching each value and voltage, flag those with no published X8R specification, and tell
you which are reflow-only.
Send your BOM to Venatech · Browse the
Walsin MLCC range · Read
NP0 vs X7R vs X5R and
MLCC reflow profile and mounting.