Part Audit Review
Review all available part information (MPN, package, pin count, description, properties). If no datasheet URL is already set, search the web for the official datasheet and update the part's Datasheet property with the URL. Then cross-check the schematic symbol, footprint, and pin descriptions against the datasheet. Summarize key specs and flag any mismatches.
Thought for 7 sec
I’ll audit the part metadata, locate the official datasheet if needed, compare the symbol and footprint against it, update the Datasheet property, and report any mismatches.
Worked for 2 mins 21 sec
Created a project doc
Audit complete. The official Littelfuse datasheet was already set, so no URL update was required; the footprint geometry matches the recommended 1812 land pattern.
Flagged issues: overly generic package property, unspecified pin types/descriptions, a legacy malformed-looking datasheet URL, ambiguous resistance wording, and a footprint filename referencing another 1812L value. Full findings: Part Audit: Littelfuse 1812L150/24MR.
Fix metadata and verify
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Part Audit: Littelfuse 1812L150/24MR
Identity and current metadata
- Manufacturer: Littelfuse
- MPN: 1812L150/24MR
- Series: 1812L PolySwitch resettable PPTC
- Lifecycle: Active
- Mount: Surface mount
- Actual package: 1812 (4532 metric), concave termination
- Pin/pad count: 2
- Description:
PTC Resettable Fuse 1.5A(hold) 3A(trip) 24VDC 20A 0.8W 1.5s 0.04Ohm SMD Solder Pad 1812 T/R - Stored datasheet: Official Littelfuse 1812L-series PDF URL is present, so no missing-URL update was required. The stored link uses HTTP and a legacy double-slash /
.pdf.pdfpath; it currently resolves through the datasheet service but should ideally be replaced with the canonical official asset URL: https://www.littelfuse.com/assetdocs/resettable-ptcs-1812l-datasheet?assetguid=ca5c80cb-504e-4a8a-8e74-0107520a1717
Key datasheet specifications
Table
| Parameter | Datasheet value |
|---|---|
| Hold current, Ihold | 1.50 A at 20 °C |
| Trip current, Itrip | 3.00 A at 20 °C |
| Maximum voltage | 24 VDC |
| Maximum fault current | 20 A |
| Typical tripped-state dissipation | 0.8 W |
| Maximum trip time | 1.5 s at 8.0 A |
| Minimum initial resistance | 0.040 Ω |
| Maximum resistance 1 hour after trip/reflow | 0.120 Ω |
| Typical resistance (product page) | 0.070 Ω |
| Operating temperature | -40 °C to +85 °C |
| Marking | LF150-24 |
| Agency approvals | cURus, TÜV |
| Packaging suffix MR | Tape and reel, 1000 pieces |
Hold current is temperature-dependent; the datasheet gives approximately 0.60 A at 85 °C and 2.05 A at -40 °C.
Symbol cross-check
- The symbol has two passive terminals, numbered 1 and 2, which is electrically correct for a non-polarized PPTC.
- Both terminals currently have Pin Type = Unspecified, and no useful pin names/descriptions are present.
- Recommended metadata: set both pin types to Passive and describe them as equivalent, non-polarized PPTC terminals (for example,
Terminal 1 — non-polarizedandTerminal 2 — non-polarized). - The part-level designator prefix F is appropriate.
Footprint cross-check
Datasheet body dimensions for this variant:
- Length A: 4.37–4.73 mm
- Width B: 3.07–3.41 mm
- Height C: 0.80–1.80 mm
Datasheet recommended land pattern:
- Pad size: 1.78 × 3.15 mm
- Inner pad gap: 3.45 mm
Current footprint:
- Pads are 1.78 × 3.15 mm.
- Pad centers are at ±2.615 mm, producing a 3.45 mm inner gap.
- Fabrication body outline is 4.55 × 3.24 mm, within the datasheet body tolerance.
- Two pads are correctly numbered 1 and 2.
Result: The copper land pattern and body outline match the official recommended geometry. The footprint asset name
1812L010DR.kicad_mod refers to another 1812L series value, but the geometry is shared and correct for 1812L150/24MR. Renaming the asset would improve traceability but is not a manufacturing mismatch.Flagged mismatches / quality issues
- Package property is too generic:
Package or Case Code = SMDshould identify1812 (4532 Metric), Concave. - Pin metadata is incomplete: both symbol pins are
Unspecifiedand lack functional descriptions; they should be passive, equivalent terminals. - Datasheet URL quality: an official URL exists, but the stored URL is legacy HTTP and malformed-looking (
//and.pdf.pdf). It should be normalized to the canonical Littelfuse asset URL. - Description resistance wording:
0.04Ohmis Rmin, not nominal/maximum resistance. The description is broadly correct but could stateRmin 0.04 Ω; R1max 0.12 Ωto avoid implying a fixed resistance. - Footprint filename traceability: the footprint is named for
1812L010DR; geometry matches this part, but the filename can confuse reviewers.
Overall assessment
The part is electrically and mechanically usable: identity, two-terminal topology, pad geometry, body outline, and headline ratings agree with Littelfuse data. The main deficiencies are metadata quality rather than copper geometry.
Identity and current metadata
Key datasheet specifications
Symbol cross-check
Footprint cross-check
Flagged mismatches / quality issues
Overall assessment
