# MJD122T4G

**MSKSEMI** · Bipolar Transistors - BJT · TO-252

MJD122T4G from MSKSEMI, in a TO-252. 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 | input | Base of the NPN transistor, with emitter-base voltage rated at -5 V (VEBO) and base current stated in the test conditions (IB = 16 mA to 80 mA). |
| 2 | COLLECTOR | passive | Collector of the NPN transistor, rated for collector-base voltage -100 V (VCBO) and continuous collector current -6 A (IC). |
| 3 | EMITTER | passive | Emitter of the NPN transistor, with a built-in damper diode between emitter and collector (E-C). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | MSKSEMI |
| Package | TO-252 |
| 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 | 100 |  |  | V | Ic=1mA,IE=0 | 3 |
| Collector-emitter breakdown voltage | V(BR)CEO | 100 |  |  | V | Ic=30mA,IB=0 | 3 |
| Emitter-base breakdown voltage | V(BR)EBO | 5 |  |  | V | IE=3mA,IC=0 | 3 |
| Collector cut-off current | ICBO |  |  | 10 | µA | VCB=100V,IE=0 | 3 |
| Collector-emitter cut-off current | ICEO |  |  | 10 | µA | VCE=50V,IE=0 | 3 |
| Emitter cut-off current | IEBO |  |  | 2 | mA | VEB=5V,IC=0 | 3 |
| DC current gain | hFE(2) | 1000 |  | 12000 |  | VCE=4V,IC=4A | 3 |
| DC current gain | hFE(3) | 100 |  |  |  | VCE=4V,IC=8A | 3 |
| Collector-emitter saturation voltage | VCE(sat)(1) |  |  | 2 | V | IC=4A,IB=16mA | 3 |
| Collector-emitter saturation voltage | VCE(sat)(2) |  |  | 4 | V | IC=8A,IB=80mA | 3 |
| Base-emitter saturation voltage | VBE(sat) |  |  | 4.5 | V | IC=8A,IB=80mA | 3 |
| Base-emitter voltage | VBE |  |  | 2.8 | V | VCE=4V,IC=4A | 3 |
| Collector output capacitance | Cob |  |  | 200 | pF | VCB=10V,IE=0,f=0.1MHz | 3 |
| Collector-base voltage (absolute maximum) | VCBO |  |  | -100 | V |  | 2 |
| Collector-emitter voltage (absolute maximum) | VCEO |  |  | -100 | V |  | 2 |
| Emitter-base voltage (absolute maximum) | VEBO |  |  | -5 | V |  | 2 |
| Collector current, continuous (absolute maximum) | IC |  |  | -6 | A | Continuous | 2 |
| Collector current, pulse (absolute maximum) | ICP |  |  | -10 | A | Pulse | 2 |
| Collector power dissipation | PC |  |  | 1.25 | W |  | 2 |
| Operating junction and storage temperature range | TJ,Tstg | -55 |  | 150 | ℃ |  | 2 |

## CAD (KiCad official)

- Symbol: `MJD122T4G`
- Footprint: `Package_TO_SOT_SMD:TO-252-2`
- 3D model: TO-252 (KiCad packages3D, STEP)
- 3D model files: `mjd122t4g-etched.step` / `mjd122t4g-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `mjd122t4g.step` / `mjd122t4g.glb` are the bare package body.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [MSKSEMI datasheet](docs/mjd122t4g-datasheet.pdf) (6 pp, sha256 `9036cfb63b13d69a`, retrieved 2026-11-05, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (text), consensus `claude-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).

[Datasheet PDF](docs/mjd122t4g-datasheet.pdf)