Power Transistor AD149 PNP, TO-3

Power Transistor AD149 PNP, TO-3

Transistors

Reference: TRAD149

Part.No: AD149

€2.95

In Stock

Immediate Dispatch

The AD149 is a classic PNP Germanium Power Transistor in a TO-3 package. Designed for high-current amplification and audio power amplifier output stages where reliability and thermal management are critical.

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Description
Product Details

AD149 PNP Germanium Power Transistor – Classic High-Current Audio Amplifier Stage

The AD149 is a robust PNP germanium power transistor, widely used in vintage and modern audio amplifier output stages. Its high collector current capability and straightforward biasing make it ideal for driving loudspeaker loads and complementary push-pull amplifier configurations.

Functions & Applications

High Collector Current: Capable of driving demanding speaker loads in audio amplifiers.
TO-3 Heatsink Mount: Large tab directly bolts to heatsinks for superior thermal dissipation.
Germanium Construction: Warmer sonic characteristics valued in vintage audio designs.
Complementary Pair: Works seamlessly with NPN BD139 or similar for push-pull stages.
Robust Design: Proven reliability in classic and retro amplifier projects.

Technical Specifications

Parameter	Value / Specification
Transistor Type	BJT (Bipolar Junction Transistor)
Polarity / Channel	PNP
Package / Case	TO-3
Collector-Emitter Voltage (Vceo)	40V
Max Collector Current (Ic)	10A
Power Dissipation (Pd)	40W (at 25°C)
Mounting Type	Stud mount (requires heatsink and mica insulator)

Frequently Asked Questions

Q: Do I need a mica insulator when mounting the AD149 to a heatsink?
A: Yes. The TO-3 case is internally connected to the collector, so electrical isolation is essential. Always use a mica insulator sheet and thermal compound between the transistor tab and heatsink to prevent short circuits.

Q: What is the complementary NPN transistor for push-pull amplifier stages?
A: The AD149 pairs well with the BD139 or similar NPN power transistor for symmetric push-pull output configurations in audio amplifiers.

Notes

Vintage germanium power transistor; typical for classic audio amplifier designs. Requires mica insulation and proper heatsinking for safe operation. Check specific datasheet for thermal resistance characteristics.

Note: Price refers to one (1) piece. The component is shipped in bulk without individual packaging.

Transistor Type: BJT (Bipolar Junction Transistor)
Transistor Polarity / Channel: PNP
Transistor Case Style: TO-3

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