component
MMBT3904E
Public Made by Adomby adom
ST Semtech Bipolar (BJT), SOT-523. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
Schematic Symbol
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PCB Footprint
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Datasheet
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README
markdownMMBT3904E
ST Semtech · Bipolar (BJT) · SOT-523
MMBT3904E from ST Semtech, in a SOT-523. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.
Pinout
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | B | input | Base; emitter-base voltage limited to 6 V (VEBO) and base saturation voltage 0.65 to 0.85 V at IC = 10 mA, IB = 1 mA. |
| 2 | E | passive | Emitter; common terminal of the NPN transistor, with VEBO max 6 V and VCEO max 40 V relative to the collector. |
| 3 | C | passive | Collector; VCBO 60 V, VCEO 40 V and continuous collector current IC up to 200 mA. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | ST Semtech |
| Package | SOT-523 |
| Category | Transistors/Thyristors |
| Pins | 3 |
CAD (KiCad official)
- Symbol:
MMBT3904E - Footprint:
Package_TO_SOT_SMD:SOT-523 - 3D model: SOT-523, generated from the KiCad footprint (body from the F.Fab outline, terminals on the pads, 0.8 mm nominal SOT-523 height). Neither the vendor nor KiCad ships a 3D model for this package, so the dimensions are nominal, not the manufacturer's CAD (STEP)
- 3D model files:
mmbt3904e-etched.step/mmbt3904e-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);mmbt3904e.step/mmbt3904e.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: ST Semtech datasheet (5 pp, sha256
e6aec3f169c23a6f, retrieved 2026-10-09, tier: lcsc) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-sonnet-5-5(text+vision), consensusclaude-opus-5-5(agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish. - CAD: KiCad official libraries (CC-BY-SA 4.0).