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TIP122 NPN Darlington Transistor
Public Made by Adomby adom
NPN Darlington power transistor, 100 V / 5 A, high current gain in TO-220.
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
markdownTIP122
STMicroelectronics · Bipolar Transistor (BJT) · TO-220
The TIP122 is a NPN Darlington power transistor rated for 100 V and 5 A continuous collector current. Its Darlington pair gives high current gain, so a small base drive from an MCU or logic pin switches large loads. It comes in a TO-220 package with integrated base-emitter resistors, part of the TIP120-127 complementary series.
Pinout
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | B | input | Base of the Darlington pair. Drive with IB up to 120 mA (absolute max); VBE(on) ≈ 2.5 V at IC = 3 A. Internal 7 kΩ resistor R1 sits between B and E, and R2 = 70 Ω is in series with the output-transistor base. |
| 2 | C | passive | Collector of the Darlington pair; also electrically connected to the TAB (heatsink mounting tab) for thermal dissipation. Rated VCEO = 100 V, IC = 5 A DC / 8 A peak. |
| 3 | E | passive | Emitter of the Darlington pair. Typically returned to the load's low-side rail (ground) in switching applications. |
Key specifications
| Parameter | Value |
|---|---|
| Type | NPN Darlington power transistor |
| Collector-emitter voltage (VCEO) | 100 V |
| Collector current (IC) | 5 A continuous (8 A peak) |
| DC current gain (hFE) | 1000 min at 3 A |
| Power dissipation | 65 W |
| Operating temperature | -65 C to 150 C |
CAD (KiCad official)
- Symbol:
tip122.kicad_sym - Footprint:
tip122.kicad_mod - 3D model: TO-220 body from KiCad
Package_TO_SOT_THT/TO-220-3_Vertical. - 3D model files:
tip122-etched.step/tip122-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);tip122.step/tip122.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: STMicroelectronics datasheet (13 pp, sha256
e726b0e3ab76c110, retrieved 2026-08-17, tier: manufacturer) - Extractor:
ds2sf(Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate. - CAD: KiCad official libraries (CC-BY-SA 4.0).