component
BD437
Public Made by Adomby adom
STMicroelectronics Bipolar Transistors - BJT, TO-126. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
Schematic Symbol
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PCB Footprint
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Datasheet
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README
markdownBD437
STMicroelectronics · Bipolar Transistors - BJT · TO-126
BD437 from STMicroelectronics, in a TO-126. 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 BD437 NPN transistor, with base current rated up to 1 A (IB). |
| 2 | Collector | passive | Collector terminal rated for 4 A continuous collector current (IC) and 7 A peak (ICM, t ≤ 10 ms), with VCEO up to 45 V. |
| 3 | Emitter | passive | Emitter terminal; emitter-base voltage is limited to 5 V (VEBO). |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | STMicroelectronics |
| Package | TO-126 |
| 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-Base Voltage (IE = 0) | VCBO | 45 | V | IE = 0 | 1 | ||
| Collector-Emitter Voltage (VBE = 0) | VCES | 45 | V | VBE = 0 | 1 | ||
| Collector-Emitter Voltage (IB = 0) | VCEO | 45 | V | IB = 0 | 1 | ||
| Emitter-Base Voltage (IC = 0) | VEBO | 5 | V | IC = 0 | 1 | ||
| Collector Current | IC | 4 | A | 1 | |||
| Collector Peak Current | ICM | 7 | A | t ≤ 10 ms | 1 | ||
| Base Current | IB | 1 | A | 1 | |||
| Total Dissipation | Ptot | 36 | W | Tc ≤ 25 °C | 1 | ||
| Storage Temperature | Tstg | -65 | 150 | °C | 1 | ||
| Max. Operating Junction Temperature | Tj | 150 | °C | 1 | |||
| Thermal Resistance Junction-case Max | Rthj-case | 3.5 | °C/W | 2 | |||
| Thermal Resistance Junction-ambient Max | Rthj-amb | 100 | °C/W | 2 | |||
| Collector Cut-off Current (IE = 0) | ICBO | 100 | µA | for BD437/438 VCB = 45 V | 2 | ||
| Collector Cut-off Current (VBE = 0) | ICES | 100 | µA | for BD437/438 VCE = 45 V | 2 | ||
| Emitter Cut-off Current (IC = 0) | IEBO | 1 | mA | VEB = 5 V | 2 | ||
| Collector-Emitter Sustaining Voltage (IB = 0) | VCEO(sus) | 45 | V | IC = 100 mA for BD437/438 | 2 | ||
| Collector-Emitter Saturation Voltage | VCE(sat) | 0.6 | V | IC = 2 A IB = 0.2 A for BD437/438 | 2 | ||
| DC Current Gain | hFE | 30 | IC = 10 mA VCE = 5 V for BD437/438 | 2 |
CAD (KiCad official)
- Symbol:
BD437 - Footprint:
Package_TO_SOT_THT:TO-126-3_Vertical - 3D model: TO-126 (KiCad packages3D, STEP)
- 3D model files:
bd437-etched.step/bd437-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);bd437.step/bd437.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: STMicroelectronics datasheet (4 pp, sha256
eff0c287adc6d211, retrieved 2026-10-27, tier: manufacturer) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-haiku-5-5(text), consensusoff(skipped (clean text read)), 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).