Scope status: Completed audit; no mutation required.
Inspected evidence
- Part: MCH3478-TL-H
- Manufacturer: ON Semiconductor / onsemi — matches datasheet
- MPN: MCH3478-TL-H — matches
- Description: “MOSFETs NCH 1.8V DRIVE SERIES” — broadly correct but incomplete
- Package: MCPH3; equivalent SC-70/SOT-323
- Pin count: 3
- Project properties: Datasheet URL, Designator Prefix
Q, Manufacturer Part Number, Manufacturer Name
- Existing Datasheet property: populated with an uploaded PDF, so per instruction it was not changed
- Current official onsemi URL:
https://www.onsemi.com/download/data-sheet/pdf/ena1353-d.pdf
Datasheet specifications
- N-channel, single power MOSFET
- VDSS: 30 V
- VGSS: ±12 V
- ID: 2 A DC; 2.5 A for ≤10 s at ≤1% duty; 8 A pulse for ≤10 µs at ≤1% duty
- RDS(on):
- 125 mΩ typ / 165 mΩ max at VGS=4.5 V, ID=1 A
- 165 mΩ typ / 235 mΩ max at VGS=2.5 V, ID=0.5 A
- 250 mΩ typ / 375 mΩ max at VGS=1.8 V, ID=0.3 A
- Threshold/cutoff voltage: 0.4–1.3 V at VDS=10 V, ID=1 mA
- Power dissipation: 0.8 W DC; 1.2 W for 10 s, both on specified 900 mm² × 0.8 mm ceramic substrate
- Channel temperature: 150 °C
- Storage: −55 to +150 °C
- No explicit θJA value was found; thermal capability is substrate-dependent.
- Exact mapping: pin 1 Gate, pin 2 Source, pin 3 Drain
Symbol findings
All three terminal numbers exist, but:
- Pins 1, 2, and 3 are all named
~
- All are typed
Unspecified
- Pin descriptions are absent
- Pin groups, sections, and terminal ordering are absent
Thus the symbol does not identify Gate, Source, or Drain despite having the correct numeric pins. The rendered custom symbol is also a plain rectangular body rather than a recognizable N-MOSF symbol.
- Three rectangular SMD pads, logically associated with pins 1–3
- Pad centers from footprint source:
- 1: (−1.062, −0.65) mm
- 2: (−1.062, +0.65) mm
- 3: (+1.062, 0) mm
- Each pad: 0.500 × 0.525 mm, rotated 90°
- Fabrication body outline: 1.6 × 2.0 mm
- Courtyard: 2.95 × 2.30 mm
- 3D STEP model is present.
- Datasheet package is approximately 2.1 × 2.0 × 0.85 mm, 0.65 mm pitch.
- Datasheet land-pattern example specifies 0.4 × 0.6 mm lands. The stored 0.500 × 0.525 mm pads therefore do not match the recommended land geometry.
- Flux pad labels display as
~; numbering is only recoverable through terminal UID association.
Mutation
- Unattempted/not applicable: Datasheet update, because the property was already non-empty.
- No symbol, footprint, or other properties were altered.
Safe to use as-is?
No. The numeric pin mapping appears recoverable and correct, but the unnamed/untyped symbol terminals create a substantial connection-error risk, and the footprint pad geometry differs from the official recommended land pattern. The part should be corrected and footprint-validated before production use.