2N2904 Temperature-Power Derating Curve
PNP General Purpose Transistor. Package, TO-39.
2N2904 Applications; High speed saturated switching
2N2904 Temperature Derating Curve
Thermal Characteristics: [2N2904, 2N2905]
Derate the 2N2904 linearly by 3.43 mW/0C above an ambient temperature of 250C
Derate the 2N2904 linearly by 17.2mW/0C above a case temperature of 250C
Use the Graph to determine how much to derate power [wattage] based on ambient operational temperature. To obtain a higher operational operating temperature apply forced air cooling, the chart covers still air [Fan Manufacturers]. Free air implies that the device is not placed within an enclosure that inhibits air flow and that near by components are not inducing additional heat to the device. Transistor Derating Curves
Temperature derating is a standard design practice for electrical engineers.
Refer to MIL-PRF-19500/290L; Semiconductor Transistor, PNP, Switching, Types, 2N2904, 2N2904A, 2N2904AL, 2N2905, 2N2905A, and 2N2905AL, JAN, JANTX, JANTXV, JANJ, JANS, JANTXVM, JANTXVD, JANTXVR, JANTXVH, JANSM, JANSD, JANSR, and JANSH, [TO-39 Metal Can package]
2N2904 Maximum Ratings:
Collector Emitter Voltage = 40 volts dc [Vceo]
Collector Base Voltage = 40 volts dc [Vcbo]
Emitter Base Voltage = 5 volts dc [Vebo]
Collector Current = 600mA [Ic]
Power Dissipation 250C = 600mW [Pd]
Operating Junction Temperature = -65 to +2000C [Tj]
Storage Temperature = -65 to +2000C [Tstg]
Heat Sink Manufacturers, Listing of Transistor Manufacturers and BJT vendors
Guideline for ; Derating Electronic Components
Note: The Top curve is thermal runaway loci and cannot be used as a derate design curve since it exceeds the maximum ratings for the 2N2904. Operating under this curve using these mounting conditions assures the device will not have a thermal runaway. This is the true inverse of the worst case thermal resistance value extrapolated out to the thermal runaway point.
