# 2SB1261-Z

**Changjiang Electronics Tech (CJ)** · Bipolar Transistors - BJT · TO-251-3L

2SB1261-Z from Changjiang Electronics Tech (CJ), in a TO-251-3L. 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 terminal of the PNP transistor, driven with IB1=-IB2=-0.1A in the switching test and -150mA for VCE(sat) and VBE(sat) at IC=-1.5A. |
| 2 | COLLECTOR | passive | Collector terminal, rated for VCBO and VCEO of -60 V, continuous collector current of -3 A, and collector power dissipation of 1 W. |
| 3 | EMITTER | passive | Emitter terminal, rated for emitter-base voltage VEBO of -7 V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Changjiang Electronics Tech (CJ) |
| Package | TO-251-3L |
| Category | Transistors |
| 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-emitter breakdown voltage | V(BR)CEO | -60 |  |  | V | IC=-1mA, IB=0 | 1 |
| Collector-base breakdown voltage | V(BR)CBO | -60 |  |  | V | IC=-100µA, IE=0 | 1 |
| Emitter-base breakdown voltage | V(BR)EBO | -7 |  |  | V | IE=-100µA, IC=0 | 1 |
| Collector cut-off current | ICBO |  |  | -10 | µA | VCB=-60V, IE=0 | 1 |
| Emitter cut-off current | IEBO |  |  | -10 | µA | VEB=-7V, IC=0 | 1 |
| DC current gain | hFE(1) | 60 |  |  |  | VCE=-2V, IC=-200mA | 1 |
| DC current gain | hFE(2) | 100 |  | 400 |  | VCE=-2V, IC=-600mA | 1 |
| DC current gain | hFE(3) | 50 |  |  |  | VCE=-2V, IC=-2A | 1 |
| Collector-emitter saturation voltage | VCE(sat) |  |  | -0.3 | V | IC=-1.5A, IB=-150mA | 1 |
| Base-emitter saturation voltage | VBE(sat) |  |  | -1.2 | V | IC=-1.5A, IB=-150mA | 1 |
| Transition frequency | fT | 50 |  |  | MHz | VCE=-5V, IC=-1.5A | 1 |
| Collector output capacitance | Cob |  |  | 40 | pF | VCB=-10V, IE=0, f=1MHz | 1 |
| Collector-base voltage | VCBO |  |  | -60 | V |  | 1 |
| Collector-emitter voltage | VCEO |  |  | -60 | V |  | 1 |
| Emitter-base voltage | VEBO |  |  | -7 | V |  | 1 |
| Collector current, continuous | IC |  |  | -3 | A |  | 1 |
| Collector power dissipation | PD |  |  | 1 | W |  | 1 |
| Junction temperature | TJ |  |  | 150 | ℃ |  | 1 |
| Storage temperature | Tstg | -55 |  | 150 | ℃ |  | 1 |

## CAD (KiCad official)

- Symbol: `2SB1261-Z`
- Footprint: `Package_TO_SOT_THT:TO-251-3_Vertical`
- 3D model: TO-251-3L (KiCad packages3D, STEP)
- 3D model files: `2sb1261-z-etched.step` / `2sb1261-z-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `2sb1261-z.step` / `2sb1261-z.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Changjiang Electronics Tech (CJ) datasheet](docs/2sb1261-z-datasheet.pdf) (2 pp, sha256 `93e57279f93d8fb2`, retrieved 2026-10-24, 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/2sb1261-z-datasheet.pdf)