# 2N3904-TA

**Changjing** · Bipolar (BJT) · TO-92-2.54mm

2N3904-TA from Changjing, in a TO-92-2.54mm. 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 | E | passive | Emitter of the NPN transistor; the datasheet gives an emitter-base breakdown voltage V(BR)EBO of 6 V (IE=10µA, IC=0) and a maximum emitter-base voltage VEBO of 6 V. |
| 2 | B | passive | Base of the NPN transistor; the datasheet gives a base-emitter saturation voltage VBE(sat) of 0.95 V maximum at IC=50mA, IB=5mA. |
| 3 | C | passive | Collector of the NPN transistor; the maximum ratings are VCBO 60 V, VCEO 40 V, continuous collector current IC 0.2 A and collector power dissipation PC 0.625 W. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | TO-92-2.54mm |
| Category | Transistors/Thyristors |
| 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 voltage | VCBO |  |  | 60 | V | Ta=25℃ (maximum ratings table header) | 1 |
| Collector-emitter voltage | VCEO |  |  | 40 | V | Ta=25℃ (maximum ratings table header) | 1 |
| Emitter-base voltage | VEBO |  |  | 6 | V | Ta=25℃ (maximum ratings table header) | 1 |
| Collector current -Continuous | IC |  |  | 0.2 | A | Ta=25℃ (maximum ratings table header) | 1 |
| Collector power dissipation | PC |  |  | 0.625 | W | Ta=25℃ (maximum ratings table header) | 1 |
| Junction temperature | TJ |  |  | 150 | ℃ | Ta=25℃ (maximum ratings table header) | 1 |
| Storage temperature | Tstg | -55 |  | 150 | ℃ | Ta=25℃ (maximum ratings table header) | 1 |
| Collector-base breakdown voltage | V(BR)CBO | 60 |  |  | V | Ta=25℃; IC=10μA, IE=0 | 1 |
| Collector-emitter breakdown voltage | V(BR)CEO | 40 |  |  | V | Ta=25℃; IC= 1mA, IB=0 | 1 |
| Emitter-base breakdown voltage | V(BR)EBO | 6 |  |  | V | Ta=25℃; IE= 10μA, IC=0 | 1 |
| Collector cut-off current | ICBO |  |  | 0.1 | μA | Ta=25℃; VCB=60V, IE=0 | 1 |
| Emitter cut-off current | IEBO |  |  | 0.1 | μA | Ta=25℃; VEB= 5V, IC=0 | 1 |
| DC current gain | hFE1 | 100 |  | 400 |  | Ta=25℃; VCE=1V, IC=10mA | 1 |
| DC current gain | hFE2 | 60 |  |  |  | Ta=25℃; VCE=1V, IC=50mA | 1 |
| DC current gain | hFE3 | 30 |  |  |  | Ta=25℃; VCE=1V, IC=100mA | 1 |
| Collector-emitter saturation voltage | VCE(sat) |  |  | 0.3 | V | Ta=25℃; IC=50mA, IB=5mA | 1 |
| Base-emitter saturation voltage | VBE(sat) |  |  | 0.95 | V | Ta=25℃; IC=50mA, IB=5mA | 1 |
| Transition frequency | fT | 300 |  |  | MHZ | Ta=25℃; VCE=20V, IC=10mA, f=100MHz | 1 |
| Delay time | td |  |  | 35 | ns |  | 1 |
| Rise time | tr |  |  | 35 | ns | VCC=3V, VBE=0.5V, IC=10mA, IB1=1mA | 1 |
| Storage time | ts |  |  | 200 | ns |  | 1 |
| Fall time | tf |  |  | 50 | ns | VCC=3V, IC=10mA, IB1=IB2=1mA | 1 |

## CAD (KiCad official)

- Symbol: `2N3904-TA`
- Footprint: `Package_TO_SOT_THT:TO-92_Inline`
- 3D model: TO-92-2.54mm (KiCad packages3D, STEP)
- 3D model files: `2n3904-ta-etched.step` / `2n3904-ta-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `2n3904-ta.step` / `2n3904-ta.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Changjing datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8588895760247640064) (2 pp, sha256 `bacae657187d6e0f`, retrieved 2026-10-17, 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/2n3904-ta-datasheet.pdf)