# TIP42B

**onsemi** · Bipolar Transistors - BJT · TO-220-3

TIP42B from onsemi, in a TO-220-3. 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; the datasheet gives a base current rating of -2 A (IB) as an absolute maximum. |
| 2 | Collector | passive | Collector terminal of the PNP transistor; the datasheet gives a collector current rating of -6 A DC and -10 A pulse (IC, ICP) as absolute maximums. |
| 3 | Emitter | passive | Emitter terminal of the PNP transistor; the datasheet gives an emitter-base voltage rating of -5 V (VEBO) as an absolute maximum. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | onsemi |
| Package | TO-220-3 |
| 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-Emitter Sustaining Voltage (TIP42B) | VCEO(sus) | -80 |  |  | V | IC = -30mA, IB = 0 | 2 |
| Collector Cut-off Current (TIP42B/42C) | ICEO |  |  | -0.7 | mA | VCE = -60V, IB = 0 | 2 |
| Collector Cut-off Current (TIP42B) | ICES |  |  | -400 | μA | VCE = -80V, VEB = 0 | 2 |
| Emitter Cut-off Current | IEBO |  |  | -1 | mA | VEB = -5V, IC = 0 | 2 |
| DC Current Gain | hFE | 30 |  |  |  | VCE = -4V, IC = -0.3A | 2 |
| DC Current Gain | hFE | 15 |  | 75 |  | VCE = -4V, IC = -3A | 2 |
| Collector-Emitter Saturation Voltage | VCE(sat) |  |  | -1.5 | V | IC = -6A, IB = -600mA | 2 |
| Base-Emitter Saturation Voltage | VBE(sat) |  |  | -2 | V | VCE = -4V, IC = -6A | 2 |
| Current Gain Bandwidth Product | fT | 3 |  |  | MHz | VCE = -10V, IC = -500mA, f = 1MHz | 2 |
| Collector-Base Voltage (TIP42B) | VCBO |  |  | -80 | V |  | 1 |
| Collector-Emitter Voltage (TIP42B) | VCEO |  |  | -80 | V |  | 1 |
| Emitter-Base Voltage | VEBO |  |  | -5 | V |  | 1 |
| Collector Current (DC) | IC |  |  | -6 | A |  | 1 |
| Collector Current (Pulse) | ICP |  |  | -10 | A |  | 1 |
| Base Current | IB |  |  | -2 | A |  | 1 |
| Collector Dissipation | PC |  |  | 65 | W | TC=25°C | 1 |
| Collector Dissipation | PC |  |  | 2 | W | TA=25°C | 1 |
| Junction Temperature | TJ |  |  | 150 | °C |  | 1 |
| Storage Temperature | TSTG | -65 |  | 150 | °C |  | 1 |

## Materials and finish

As the datasheet states them (page.json `metadata.appearance`; the 3D model's colours follow it).

| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| housing | PC |  | IB Base Current -2 A PC Collector Dissipation (TC=25°C) 65 W | 1 |

## CAD (KiCad official)

- Symbol: `TIP42B`
- Footprint: `Package_TO_SOT_THT:TO-220-3_Vertical`
- 3D model: TO-220-3 (KiCad packages3D, STEP)
- 3D model files: `tip42b-etched.step` / `tip42b-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `tip42b.step` / `tip42b.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [onsemi datasheet](https://www.onsemi.com/pdf/datasheet/tip42b-d.pdf) (5 pp, sha256 `6de79efcef19d13b`, retrieved 2026-11-02, tier: manufacturer)
- **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/tip42b-datasheet.pdf)