Attribute Schema Library
Attribute schemaelectronic components

Capacitors Attributes

A capacitor catalog is one category name covering six unrelated physics. Ceramic (MLCC), aluminum electrolytic, tantalum, tantalum polymer, film and supercapacitor share a tree but almost no attributes: temperature characteristic is meaningless on an electrolytic, endurance hours are meaningless on an MLCC.

Buyers are design engineers and contract-manufacturer sourcing desks working a BOM line. They arrive with parameters, not words, and they cross-reference — same value, different manufacturer, has to drop in.

Three things make the data hard. Variant explosion: one MLCC series spans thousands of orderable parts across capacitance, voltage, tolerance, case size and thickness, and each axis is its own field. Code drift: the same value arrives as 104, 0.1uF, 100nF and 0.1 MFD; the same footprint arrives as 0402 imperial and 1005 metric. And the parameters that actually decide the design — DC bias behaviour, ripple-current frequency multipliers, aging rate, endurance curves — live in datasheet graphs and PDF tables, not in the supplier's price file.

Core

Every SKU needs these. Without them the record is not a product, it is a row.

Capacitor Type
enum
Aluminum Electrolytic

Root facet. Decides which other parameters even exist: temperature characteristic for ceramics, endurance hours and ripple for electrolytics.

Capacitance
number · µF
0.1 µF (100 nF)

The BOM line value. Buyers arrive knowing it and filter on it first. Must be a number in one unit, not a string.

Capacitance Tolerance
enum · %
±10% (K)

Timing, filter and resonant circuits need ±5% or tighter; bulk decoupling tolerates ±20%. EIA letter codes must resolve to a percentage.

Voltage - Rated (DC and AC)
number · VDC / VAC
50 VDC; 630 VDC / 250 VAC (film)

The derating rule of every design. AC and DC limits are separate ratings: a 630 VDC film capacitor is often rated only 250 VAC.

Dielectric / Temperature Characteristic
enum
X7R (-55 °C to +125 °C, ±15%)

EIA RS-198 code fixes temperature range and capacitance drift. C0G is Class 1 and stable; X7R, X5R, Y5V are Class 2 and are not.

Package / Case
enum
0805 (2012 Metric)

Footprint on the board. Must state the measurement system — imperial 0402 and metric 1005 are the same part.

Mounting Type
enum
Surface Mount

Splits SMT reels from through-hole radial cans and screw-terminal parts. Drives the assembly process, not just the footprint.

Polarization
enum
Polar

Reverse voltage on a polar electrolytic vents the can. Bipolar aluminum parts exist and are a distinct filter value.

Operating Temperature Range
range · °C
-55 °C ~ 125 °C

Automotive underhood and industrial specs are written as a range. A -40 °C to +85 °C part gets rejected against a 125 °C requirement.

Manufacturer Part Number (MPN)
identifier
GRM21BR71H104KA01L (Murata)

The cross-reference key. Buyers paste an MPN straight off a BOM; without the exact manufacturer string it resolves to nothing.

Differentiating

What buyers actually compare on. This is where catalogs win or lose the filter.

ESR @ Test Frequency
number · mΩ
85 mΩ @ 100 kHz, 20 °C

Sets ripple heating and SMPS loop stability. Meaningless without frequency and temperature — the 120 Hz and 100 kHz values differ hugely.

Ripple Current @ Frequency and Temperature
number · mA rms
1,120 mA rms @ 100 kHz, 105 °C

The rating that decides whether the can survives. Quoted rms at 120 Hz for line filtering or 100 kHz for switching supplies.

Lifetime / Endurance @ Temperature
number · hours
5,000 Hrs @ 105 °C

Electrolytic wear-out spec. 2,000 h vs 10,000 h at 105 °C is the entire comparison in power supply and LED lighting designs.

Compliance & identifiers

Standards, regulatory data, and the identifiers channels reject you for missing.

Ratings / Qualification
enum
AEC-Q200 Grade 1

AEC-Q200 is the passive-component stress qualification. Automotive buyers filter on it, and an unqualified substitute fails PPAP.

Safety Class and Agency Approvals
enum
X2, 305 VAC, IEC 60384-14 (ENEC, UL, CQC)

Mains-connected parts need X/Y class per IEC 60384-14 plus agency marks. X is line-to-line; Y is line-to-ground.

RoHS / REACH Status
enum
RoHS 3 (EU 2015/863); no SVHC > 0.1%

Required on EU-bound quotes and most customer part-approval forms. Lead-bearing terminations still ship for hi-rel and exempt uses.

Country of Origin
enum
Japan

Drives HTS classification, tariff exposure and customer trade-compliance screens. Asked on effectively every RFQ of size.

GTIN-13 / UPC
identifier
4548736012345

Required by marketplaces and retail-style channels. Cut tape, full reel and bulk are separate GTINs where the maker assigns them.

The fields that aren't in the schema at all

What most capacitors catalogs are missing.

The table above is the schema most catalogs already have. These are the attributes that usually aren't in it — each one surfaced by a signal from the live market rather than by an audit of what's already there. This is what Anglera's Schema Foundry does on a real catalog, in this category.

Supplier signal
+ Capacitance @ Applied DC Bias

Murata SimSurfing and TDK's Characteristic Viewer publish a DC bias curve for every Class 2 part. No mainstream distributor filter rail lets a buyer ask for effective capacitance at 12 V.

A 22 µF 25 V X5R chosen on its nominal value delivers a fraction of it at working voltage. The design fails validation and the BOM line gets re-specced away from you.

Competitor signal
+ Height - Seated (Max) / Thickness (Max)

Digi-Key exposes Height - Seated (Max) as its own facet. Most distributor records stop at the case code, yet 0805 X7R parts ship anywhere from 0.60 mm to 1.45 mm thick.

A buyer with a shield-can or board-to-board clearance limit cannot filter, so they buy where they can. Wrong-thickness parts come back as fit returns.

Supplier signal
+ Termination Style (standard vs flexible/soft)

KEMET FT-CAP, KYOCERA AVX FLEXITERM and TAIYO YUDEN soft-termination MLCCs are sold as distinct lines. Catalogs that stock them bury the resin-layer termination in free text or drop it.

The buyers who need it cannot find it, and standard-termination parts get quoted into flex-crack applications on automotive and large-format boards.

Competitor signal
+ Product Lifecycle Status and Last-Time-Buy Date

Digi-Key publishes Product Status — Active, Not For New Designs, Obsolete, Last Time Buy — as a filter. Catalogs built off a supplier price file carry stock but no lifecycle state.

An engineer designs in an NRND part and finds out at production ramp. Sourcing teams route BOM scrubs to catalogs that publish status, and the rest of the BOM follows.

Supplier signal
+ Aging Rate (Class 2 dielectric)

X7R and X5R datasheets state a capacitance aging rate in %/decade hour against a reference measurement time. The number does not appear as a catalog attribute anywhere.

Timing and filter designs specced on the day-one value drift out of tolerance in service, and the buyer must open every PDF to compare two nominally identical parts.

How Schema Foundry finds these

Messy in, governed out.

The same value, spelled every way electronic components suppliers spell it. A filter only works once they agree.

Capacitance
1040.1uF100nF0.1 MFD100000pF.1 µF
0.1 µF

EIA 3-digit code, legacy MFD and pF/nF/µF all name one part. Unit-blind text sorting scatters a single value across four filter buckets.

Dielectric / Temperature Characteristic
COGC0GNP0NPOClass 11B
C0G (NP0)

C0G is C-zero-G. Suppliers send letter-O 'COG' and IEC codes for the same dielectric; string matching treats them as three different parts.

Package / Case
040210051005 Metric010051.0x0.5mmEIA 0402
0402 (1005 Metric)

Imperial 0402 = metric 1005, and imperial 01005 = metric 0402. A bare '1005' is ambiguous until the measurement system is stated.

Voltage - Rated
50V50VDC50 Vdc50WVDC1H50 volts
50 VDC

EIA voltage codes (1H = 50 V) and WVDC arrive mixed. Dropping the suffix also merges AC and DC limits, which are not interchangeable.

What buyers ask

Every one of these should be answerable from the attributes above. If it isn't, that's a gap.

  • How much capacitance do I actually keep at 12 V on this 22 µF 25 V X5R?
  • Is this a drop-in for the Nichicon UHE — same can size, lead pitch, ripple and endurance?
  • What's the ESR at 100 kHz, not at 120 Hz?
  • Will an 0805 X7R fit under a 1.2 mm shield can?
  • Is this part AEC-Q200 qualified, and which grade?
  • Is it still Active, or is it NRND with a last-time-buy date?
  • Can I put this across the AC line, or is it a DC-only film cap?
  • Is the termination soft/flexible, or will it crack when the board flexes?

What channels require

The same SKU, different mandatory fields per destination.

Distributor parametric search (own site)
CapacitanceVoltage - Rated (DC and AC)Dielectric / Temperature CharacteristicPackage / CaseMounting TypeOperating Temperature Range
Octopart / Nexar component search
Manufacturer Part Number (MPN)Manufacturer nameDatasheet URLStock and price breaksProduct lifecycle statusPackage / Case
ECIA TrustedParts (authorized-distributor pool)
Manufacturer Part Number (MPN)Manufacturer nameAuthorized-line flagStock quantityPrice breaksDatasheet URL
Amazon Business
GTIN-13 / UPCBrandManufacturer Part Number (MPN)Package quantityCountry of OriginRoHS / REACH Status

Capacitors data, in practice

Why isn't capacitance and voltage enough to identify a capacitor?

It doesn't resolve to one orderable part. "10 µF 25 V" describes an 0603 X5R MLCC, a molded tantalum, a radial aluminum can and a tantalum polymer chip — different ESR, different failure modes, different price by two orders of magnitude. Even inside MLCC, 10 µF 25 V X5R exists in 0805, 1206 and 1210 at several thicknesses, each with its own DC bias curve. A record needs type, capacitance, tolerance, voltage, dielectric, case and mounting before it resolves. Catalogs that stop at capacitance and voltage return filter pages where dozens of parts look identical and none are interchangeable.

How do I read an EIA RS-198 dielectric code?

Three characters: low temperature limit, high temperature limit, maximum capacitance change across that range. X7R = -55 °C to +125 °C, ±15%. X5R = -55 °C to +85 °C, ±15%. Y5V = -30 °C to +85 °C, +22%/-82%. Z5U = +10 °C to +85 °C, +22%/-56%. C0G (also written NP0) is the odd one out — it's Class 1, roughly ±30 ppm/°C, and is not part of the same coding scheme. The Class 1 / Class 2 split matters more than the letters: Class 2 dielectrics are ferroelectric, so they lose capacitance under DC bias and age with time. Class 1 does neither.

Why does ESR need a test frequency attached to it?

Because ESR is frequency and temperature dependent, and the difference is not a rounding error. An aluminum electrolytic quoted at 120 Hz and the same part quoted at 100 kHz are different numbers, and the 100 kHz figure is what matters for a switching converter. This is why Digi-Key carries the condition inside the value — "85 mΩ @ 100 kHz". Ripple current has the identical problem: rated rms at 120 Hz for line-frequency filtering or 100 kHz for SMPS output, with a frequency-correction factor table in the datasheet that never reaches the catalog. A bare "ESR: 85 mΩ" is unusable and invites a return.

Do we need safety and qualification fields if we only sell commercial parts?

If you list film or ceramic parts that can be connected to the mains, yes. IEC 60384-14 classes them X1/X2 (line-to-line, failure doesn't shock) and Y1/Y2 (line-to-ground, failure can), with agency marks (ENEC, UL, CQC) and a humidity grade — Grade IIIB means the part survived 85 °C / 85% RH for 1000 hours under rated AC voltage. Buyers filter on class and on the marks, because their end product's certification depends on them. AEC-Q200 is the parallel field for automotive: an unqualified part that is electrically identical still fails the customer's part approval.

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