component
MMSTA42
Public Made by Adomby adom
Changjing Bipolar Transistors - BJT, SOT-323. 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
markdownMMSTA42
Changjing · Bipolar Transistors - BJT · SOT-323
MMSTA42 from Changjing, in a SOT-323. 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 | BASE | passive | Base terminal of the NPN transistor; the datasheet limits the emitter-base voltage to VEBO 5 V and the emitter-base breakdown to V(BR)EBO 5 V. |
| 2 | EMITTER | passive | Emitter terminal of the NPN transistor; the datasheet limits the emitter-base voltage to VEBO 5 V maximum. |
| 3 | COLLECTOR | passive | Collector terminal of the NPN transistor; the datasheet rates VCBO 300 V, VCEO 300 V, IC 0.2 A continuous and ICM 0.5 A pulsed. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | SOT-323 |
| Category | Triode/MOS Tube/Transistor |
| Pins | 3 |
Electrical characteristics
Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).
| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Collector-base breakdown voltage | V(BR)CBO | 300 | V | IC=100μA,IE=0 | 1 | ||
| Collector-emitter breakdown voltage | V(BR)CEO | 300 | V | IC=1mA,IB=0 | 1 | ||
| Emitter-base breakdown voltage | V(BR)EBO | 5 | V | IE=100μA,IC=0 | 1 | ||
| Collector cut-off current | ICBO | 0.25 | μA | VCB=200V,IE=0 | 1 | ||
| Emitter cut-off current | IEBO | 0.1 | μA | VEB=5V,IC=0 | 1 | ||
| DC current gain | hFE(1) | 60 | VCE=10V,IC=1mA | 1 | |||
| DC current gain | hFE(2) | 100 | 200 | VCE=10V,IC=10mA | 1 | ||
| DC current gain | hFE(3) | 75 | VCE=10V,IC=30mA | 1 | |||
| Collector-emitter saturation voltage | VCE(sat) | 0.2 | V | IC=20mA,IB=2mA | 1 | ||
| Base-emitter saturation voltage | VBE(sat) | 0.9 | V | IC=20mA,IB=2mA | 1 | ||
| Transition frequency | fT | 50 | MHz | VCE=20V,IC=10mA,f=30MHz | 1 | ||
| Collector-base voltage | VCBO | 300 | V | Ta=25℃ | 1 | ||
| Collector-emitter voltage | VCEO | 300 | V | Ta=25℃ | 1 | ||
| Emitter-base voltage | VEBO | 5 | V | Ta=25℃ | 1 | ||
| Collector current -continuous | IC | 0.2 | A | Ta=25℃ | 1 | ||
| Collector current -pulsed | ICM | 0.5 | A | Ta=25℃ | 1 | ||
| Collector power dissipation | PC | 0.3 | W | Ta=25℃ | 1 | ||
| Operation junction and storage temperature range | TJ,Tstg | -55 | 150 | ℃ | 1 | ||
| Thermal resistance from junction to ambient | RθJA | 417 | ℃/W | 1 |
CAD (KiCad official)
- Symbol:
MMSTA42 - Footprint:
Package_TO_SOT_SMD:SOT-323_SC-70 - 3D model: SOT-323 (KiCad packages3D, STEP)
- 3D model files:
mmsta42-etched.step/mmsta42-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);mmsta42.step/mmsta42.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Changjing datasheet (4 pp, sha256
001b875a333175a5, retrieved 2026-11-04, tier: lcsc) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-haiku-5-5(text), consensusclaude-sonnet-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).