Part Audit
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 10 sec
I’ll audit the part metadata, source the official manufacturer documentation if needed, then verify the symbol, footprint, and pin definitions and record any discrepancies.
Worked for 7 mins 47 sec
Created a project doc
Audit complete. The footprint geometry matches Littelfuse’s official SM8S land pattern, but the symbol does not visibly render, pin types/descriptions are incomplete, and the footprint asset is incorrectly named
SLD5S18A; I filed an internal part-quality report.The Datasheet property was already populated, so it was not changed, although its URL appears malformed. Full specifications and comparisons are in Part Audit.
Fix metadata and symbol
Update datasheet URL
Fix symbol pins
Add pin descriptions
Rename footprint asset
Refine this doc
Ask about this doc
Part Audit
Identification and stored metadata
- MPN: SM8S33A
- Manufacturer: Littelfuse
- Description: ESD Protection Diodes / TVS Diodes TVS SMTO HI-POWER 33A 5mA 2uA
- Stored part type: Circuit Protection Devices
- Mount: Surface Mount
- Designator prefix: D
- Stored pin/pad count: 3
- Stored Datasheet URL: Present, but the hostname appears malformed (
mousTVSer.com). Per the requested rule, it was not replaced because the Datasheet property was not empty. - Official manufacturer datasheet: https://www.littelfuse.com/assetdocs/tvs-diode-sm8s-datasheet?assetguid=59636cd8-2d53-4eb3-b51b-1f5d4bf30c3e
- Official series page: https://www.littelfuse.com/products/overvoltage-protection/tvs-diodes/high-power/sm8s
Key SM8S33A specifications
Table
| Parameter | Official value |
|---|---|
| Device type | Unidirectional high-power TVS diode |
| Package | SMTO-263 |
| Peak pulse power | 7000 W, 10/1000 us waveform |
| Reverse standoff voltage (VR) | 33 V |
| Breakdown voltage (VBR at 5 mA) | 36.7 V min, 40.6 V max |
| Max leakage at VR, 25 C | 2 uA |
| Max leakage at VR, 150 C | 50 uA |
| Peak pulse current (IPP) | 132 A |
| Max clamping voltage at IPP | 53.3 V |
| Forward surge current | 1000 A, 8.3 ms half-sine |
| Max forward voltage | 1.8 V at 100 A |
| Junction/storage temperature | -55 C to +175 C |
| Typical RthetaJC | 0.9 C/W |
| Typical RthetaJA | 55 C/W |
| Polarity marking | Cathode band |
Symbol audit
The part contains terminals K / pin 1, A_1 / pin 2, and A_2 / pin 3. The two anode terminals represent the two physical anode-side solder lands, while the cathode is the opposite terminal.
Mismatches and quality gaps
- Symbol graphic is not visibly rendered in inspection. Only three isolated terminal objects were found; the schematic image was blank. This is a major usability issue because the symbol does not visibly communicate a TVS diode or its polarity.
- All three pin types are
Unspecified. They should be passive pins for a diode/TVS component. - Pin descriptions are absent. Recommended descriptions: pin 1
Cathode; pins 2 and 3Anode (internally common). - No explicit pin grouping/section/orientation/order metadata was found. This is less critical electrically but reduces symbol quality and maintainability.
- The manufacturer datasheet identifies the functional device as a two-terminal diode and does not provide numeric pin numbering. Therefore the project's three physical-pad mapping must be communicated clearly in the symbol and pin descriptions.
Footprint audit
The footprint asset is named
SLD5S18A.kicad_mod, although the actual part is SM8S33A. The name is misleading and should be renamed or replaced with an SM8S-family-specific asset name, even though the geometry largely matches the official SM8S land pattern.Geometry comparison
Table
| Footprint feature | Project | Datasheet land pattern | Result |
|---|---|---|---|
| Small cathode pad | 2.30 x 3.00 mm | 2.30 x 3.00 mm | Match |
| Central large anode pad | 7.01 x 8.89 mm | 7.01 x 8.89 mm | Match |
| Long anode pad | 2.16 x 10.50 mm | 2.16 x 10.50 mm | Match |
| Small-to-central spacing | 8.455 mm center-to-center | Derived from 8.13 mm and 0.81 mm dimensions | Consistent |
| Central-to-long spacing | 4.585 mm center-to-center | Derived from official outline | Consistent |
| Overall courtyard | 12.50 x 17.27 mm | Not specified as a courtyard | Plausible |
The three pads are mapped as K, A_1, and A_2, which is electrically plausible for the package geometry. The two anode pads should be documented as internally common.
Footprint concerns
- The footprint description says SMTO-263, which is correct.
- The footprint tag says TVS Diode (Uni-directional), which is correct.
- The footprint asset filename and embedded module/value text reference SLD5S18A, not SM8S33A. This is a metadata mismatch and creates traceability risk.
- The footprint includes a 3D model named SM8S33A.stp, which is consistent with the target MPN.
- Paste is enabled on all three pads. The official datasheet supplies a soldering land pattern but does not state that any pad should omit paste, so no paste mismatch is identified.
Overall assessment
- Electrical identity and key stored metadata: Correct.
- Datasheet property: Present, but likely malformed/non-authoritative; official Littelfuse URL is documented above.
- Footprint copper geometry: Matches the official recommended land pattern closely.
- Footprint naming/traceability: Mismatched (
SLD5S18A). - Symbol and pin metadata: Incomplete and potentially unusable because the graphic does not render, pin types are unspecified, and descriptions are missing.
Recommended corrections
- Replace the stored Datasheet URL with the official Littelfuse URL despite the property being non-empty, after explicit approval if strict adherence to the original update condition is required.
- Restore or recreate a visible unidirectional TVS diode symbol with clear cathode/anode polarity.
- Set all pins to passive and add descriptions: K = cathode; A_1/A_2 = internally common anode pads.
- Rename or replace the footprint asset so its filename and embedded identity reference SM8S/SM8S33A rather than SLD5S18A.
- Preserve the current pad geometry, which agrees with the official land pattern.
Identification and stored metadata
Key SM8S33A specifications
Symbol audit
Mismatches and quality gaps
Footprint audit
Geometry comparison
Footprint concerns
Overall assessment
Recommended corrections
