2N5581 Temperature-Power Derating Curve
NPN Switching Transistor. Package, TO-46.
2N5581 Temperature Derating Curve
Use the Graph to determine the required 2N5581 power derating [wattage] based on ambient operational temperature. The maximum wattage of 3 watts is available at 250C and begins to fall off above 300C in still air.
The graph only relates to the 2N5581, there are no other devices near by that could generate additional heat. In a real design the circuit board will contain components that are also generating heat which are not accounted for in the graph.
Transistor Derating Curves
Temperature derating is a common design practice for electrical engineers.
Refer to MIL-PRF-19500/423F; Semiconductor Device, Transistor, NPN, Silicon, Switching, Type 2N5581 and 2N5582, JAN, JANTX, and JANTXV, [TO-46]
2N5581 Maximum Operation Ratings:
Collector Emitter Voltage = 50 volts
Collector Base Voltage = 75 volts
Emitter Base Voltage = 6.0 volts
Power Dissipation 250C = 3.0 Watts
Operating Temperature = -65 to +2000C
Listing of Transistor Manufacturers and BJT vendors
Pinout note; Terminal 1 Emitter, Terminal 2 Base, Terminal 3 Collector.
How to Derate; Guideline for Derating Electronic Components
MIL-PRF-19500; Semiconductor Devices, General Specification
MIL-STD-750; Test Methods for Semiconductor Devices
