2N4931 Temperature-Power Derating Curve [2N4930, 2N3743]
PNP Silicon High Voltage Transistor. Package, TO-39 Metal Can [Through-Hole].
2N4931 Transistor Operational Power Derating Curve
Use the Graph to determine how much to derate power [wattage] based on ambient operational temperature, or in this instance Case temperature [with a Heat Sink]. How to read the curves; Interpreting Deraring Curves.
Another method would be;
Derate the 2N4931 linearly 5.71 mW/0C for TA > +250C
Derate the 2N4931 linearly 28.6 mW/0C for TC > +250C
Additional Transistor Derating Curves
Temperature derating is a standard design practice for electrical engineers.
Refer to MIL-PRF-19500/397H; Semiconductor Device, Transistor, PNP, Silicon, Types 2N3743, 2N3743U4, 2N4930, 2N4930U4, 2N4931, and 2N4931U4, JAN, JANTX, JANTXV, JANS, JANHC, and JANKC, [TO-39, U4 surface mount, Semiconductor-Die]
2N4931 Maximum Operational Ratings:
Collector Emitter Voltage = 250 volts dc [Vce]
Collector Base Voltage = 250 volts dc [Vcb]
Emitter Base Voltage = 5 volts dc [Veb]
Power Dissipation = 1 Watt [250C]
Operating Temperature = -65 to +2000C [Tj], 2N4931
Storage Temperature = -65 to +2000C [Tstg], 2N4931
Refer to the data sheet for additional electrical characteristics
Listing of Transistor Manufacturers and vendors.
How to Derate; Guideline for Derating Electronic Components
