Transistor BD121 NPN, 60V, 5A, 45W TO-3

Transistor BD121 NPN, 60V, 5A, 45W TO-3

Transistor BD121 NPN, 60V, 5A, 45W TO-3

Transistor BD121 NPN, 60V, 5A, 45W TO-3

Power Transistor BD121 NPN, 5A TO-3

Transistors

Reference: TRBD121

Part.No: BD121

€3.55

In Stock

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The BD121 is an NPN Bipolar Junction Transistor (BJT) power transistor in a TO-3 metal package. Designed for medium-power switching and amplification stages such as audio output, motor drivers and voltage regulators.

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Description
Product Details

BD121 NPN Power Transistor - 60V / 5A Switching & Amplification

The BD121 is an NPN power transistor housed in the rugged TO-3 metal case, built to handle up to 60V and 5A with 45W of power dissipation. It is a solid choice for audio amplifier output stages, DC motor control and linear voltage regulators where a robust, easy-to-heatsink package is needed.

Functions & Applications

High Current Handling: Supports up to 5A collector current for demanding power stages.
Robust TO-3 Package: Metal case with excellent thermal transfer, easy to mount on a heatsink.
45W Power Dissipation: Suitable for audio amplifier outputs and motor driver circuits.
60V Collector-Emitter Rating: Provides headroom for typical automotive and low-voltage power supply designs.

Technical Specifications

Parameter	Value / Specification
Transistor Type	BJT (Bipolar Junction Transistor)
Polarity / Channel	NPN
Package / Case	TO-3
Collector-Emitter Voltage (Vceo)	60V
Max Collector Current (Ic)	5A
Power Dissipation (Pd)	45W
Mounting Type	Through-Hole, Heatsink Mountable

Frequently Asked Questions

Q: Does the BD121 need a heatsink?
A: Yes, when operating near its 45W power dissipation limit a heatsink is required, since the TO-3 case is designed for efficient heat transfer to an external mount.

Q: Can the BD121 be used to drive a DC motor or relay coil?
A: Yes, it can switch loads drawing up to 5A, making it suitable for small DC motors and relay coils, provided a flyback diode is used for inductive loads.

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: NPN
Transistor Case Style: TO-3

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