Part Number: 2N449
Function: 15V, -20mA, NPN Transistor.
Package: 3-Pin TO-39 Type
Manufacturer: New Jersey Semiconductor
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Description
The 2N449 is a low-power bipolar junction transistor rated for 15V operation and a maximum collector current of -20mA, typically used in small-signal applications. It offers modest power dissipation and is suitable for low-level amplification and switching tasks in compact electronic designs. This transistor is commonly applied in signal processing, low-current switching, and general-purpose analog circuits.
Features
- Low power dissipation of 65mW
- Suitable for small-signal amplification
- Compact and efficient for low-current circuits
- Stable operation within limited temperature range
Absolute Maximum Ratings (Tc = 25 °C)
| Parameter | Symbol | Value | Unit |
| Collector-Base Voltage | VCBO | 15 | V |
| Emitter-Base Voltage | VEBO | 15 | V |
| Collector Current | IC | -20 | mA |
| Collector Power Dissipation | PC | 0.065 | W |
| Junction Temperature | Tj | 85 | °C |
| Storage Temperature | Tstg | -55 to 85 | °C |
Design Notes
- Ensure collector current remains within 20mA to avoid device damage
- Suitable for low-power circuits with minimal heat generation
- Biasing must be carefully designed for stable small-signal amplification
- Limited thermal range requires controlled operating environment
- Not suitable for high-frequency or high-power applications
Typical Circuit Usage
- Low-level signal amplification
- Small current switching circuits
- Sensor interface stages
- Pre-amplifier circuits
- Basic transistor switching applications
How to Choose This Part
- Select for low-voltage, low-current applications
- Ideal for compact and low-power analog designs
- Ensure thermal limits are not exceeded in operation
- Use where high gain or power handling is not critical
- Consider alternatives for wider temperature or higher current needs
Applications
- Signal processing circuits
- Low-power electronic devices
- Instrumentation circuits
- Educational and prototyping designs
- Embedded analog interfaces
Alternative / Equivalent Products
- 2N3904 (general-purpose NPN transistor)
- BC547 (low-noise small-signal transistor)
- 2N2222 (higher current alternative)
- PN2222A (plastic package variant)
- BC548 (similar small-signal transistor)
2N449 Datasheet
