Conductor Products, Inc. - NPN TO-39/TO-5 # 2N5058 Silicon NPN Power Transistor Technical Documentation
*Manufacturer: MOTOROLA*
## 1. Application Scenarios
### Typical Use Cases
The 2N5058 is a silicon NPN power transistor designed for medium-power amplification and switching applications. Its primary use cases include:
Power Amplification Stages
- Audio frequency power amplifiers (up to 1.2A continuous collector current)
- Driver stages for higher power output devices
- Class A/B amplifier configurations in consumer electronics
Switching Applications
- Relay and solenoid drivers
- Motor control circuits (DC motors up to 60V)
- Power supply switching regulators
- Industrial control system interfaces
Linear Regulation
- Series pass elements in voltage regulators
- Current source/sink applications
- Electronic load controllers
### Industry Applications
Consumer Electronics
- Audio amplifier output stages in home stereo systems
- Television vertical deflection circuits
- Power supply control in household appliances
Industrial Automation
- Motor drive circuits for conveyor systems
- Solenoid valve controllers in fluid control systems
- Power interface circuits for PLC output modules
Telecommunications
- RF power amplifier driver stages
- Line drivers in communication equipment
- Power management in telecom infrastructure
Automotive Systems
- Electronic ignition systems
- Power window and seat motor controllers
- Automotive lighting control circuits
### Practical Advantages and Limitations
Advantages:
- Robust construction with TO-39 metal package for excellent thermal performance
- High current gain (hFE 20-60 at 1A) ensuring good current amplification
- Moderate switching speed (typical fT of 4MHz) suitable for many power applications
- Good secondary breakdown characteristics for reliable operation
- Wide operating temperature range (-65°C to +200°C)
Limitations:
- Limited maximum collector current (1.2A) restricts high-power applications
- Moderate frequency response not suitable for RF applications above 4MHz
- Requires careful thermal management at higher power levels
- Higher saturation voltage compared to modern power MOSFETs
- Relatively large package size compared to SMD alternatives
## 2. Design Considerations
### Common Design Pitfalls and Solutions
Thermal Management Issues
*Pitfall:* Inadequate heat sinking leading to thermal runaway and device failure
*Solution:* Always calculate maximum power dissipation and provide appropriate heat sinking
*Calculation Example:* P_D(max) = (T_Jmax - T_A) / θ_JA = (200°C - 25°C) / 83.3°C/W ≈ 2.1W
Secondary Breakdown Protection
*Pitfall:* Operating outside safe operating area (SOA) causing device destruction
*Solution:* Implement current limiting and ensure operation within SOA boundaries
*Implementation:* Use series resistors and monitor collector current
Storage and Handling
*Pitfall:* ESD damage during handling and installation
*Solution:* Follow proper ESD protocols and use anti-static packaging
### Compatibility Issues with Other Components
Driver Circuit Compatibility
- Requires adequate base drive current (typically 50-100mA for saturation)
- Compatible with standard logic families through appropriate interface circuits
- May require Darlington configuration for high current gain applications
Load Compatibility
- Suitable for inductive loads with proper flyback diode protection
- Compatible with resistive loads up to maximum ratings
- Requires snubber circuits for capacitive loads
Power Supply Considerations
- Operating voltage range: 5V to 60V DC
- Requires stable power supply with adequate current capability
- Decoupling capacitors essential for stable operation
### PCB Layout Recommendations
Thermal Management
- Use generous copper pours for heat dissipation
- Consider thermal vias for improved heat transfer
- Maintain adequate clearance for heat sink installation
Power Routing
- Use wide traces for collector and emitter connections (minimum 50 mil width for
