# TIP42A

**STMicroelectronics** · Bipolar (BJT) · TO-220

TIP42A from STMicroelectronics, in a TO-220. 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 terminal that controls the PNP transistor; for PNP types voltage and current values are negative, with IB max 3 mA and VEBO max 5 V. |
| 2 | C | passive | Collector terminal (also connected to the TO-220 tab per package drawing), with VCEO of 60 V, VCBO of 60 V, IC of 6 A and ICM of 10 A (negative for PNP). |
| 3 | E | passive | Emitter terminal of the PNP transistor, with VEBO (emitter-base) rating of 5 V and negative voltage and current values for PNP types. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | STMicroelectronics |
| Package | TO-220 |
| Category | Transistors/Thyristors |
| Pins | 3 |

## CAD (KiCad official)

- Symbol: `TIP42A`
- Footprint: `Package_TO_SOT_THT:TO-220-3_Vertical`
- 3D model: TO-220 (KiCad packages3D, STEP)
- 3D model files: `tip42a-etched.step` / `tip42a-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `tip42a.step` / `tip42a.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [STMicroelectronics datasheet](https://www.st.com/resource/en/datasheet/tip42a.pdf) (10 pp, sha256 `f9b4b425f6166006`, retrieved 2026-11-06, tier: manufacturer)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (text+vision), consensus `claude-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).

[Datasheet PDF](docs/tip42a-datasheet.pdf)