2N2906A Temperature-Power Derating Curve [2N2907A]
PNP General Purpose Silicon Transistor. Package, TO-18 Metal Can.
2N2906A Transistor Derating Curve
Use the Graph to determine how much power to derate based on ambient temperature. Attaching a heat sink to the metal TO-18 package will allow for higher temperature operation at the same power dissipation. Applying forced air cooling to the system will also increase the operational temperature range. The curves cover still-air or free-air.
Transistor Derating Curves
Temperature derating is a standard design practice for electrical engineers.
Refer to MIL-PRF-19500/291R; Semiconductor, Transistor, PNP, Switching, Types 2N2906A, 2N2906AL, 2N2907A, 2N2907AL, 2N2906AUA, 2N2907AUA, 2N2906AUB, 2N2906AUBC, 2N2907AUB, and 2N2907AUBC, JAN, JANTX, JANTXV, JANJ, JANS, JANSM, JANSD, JANSP, JANSL, JANSR, JANSF, JANSG, JANSH JANHCB, JANHCD JANKCB, JANKCD JANKCBM, JANKCBD, JANKCBP, JANKCBL, JANKCBR, JANKCBF, JANKCBG, and JANKCBH, [TO-18 package]
2N2906A Maximum Ratings:
Collector Emitter Voltage = 60 volts dc
Collector Base Voltage = 60 volts dc
Emitter Base Voltage = 5 volts dc
Collector Current = 600mA dc
Power Dissipation 250C = 400mW
Operating Temperature = -65 to +2000C
Storage Temperature = -65 to +2000C
How to interpret the chart;
The top curve [right-most] represents the maximum permissible operating range of the 2N2906. At no time should the junction temperature of the 2N2906 [or 2N2907] exceed 200C. The next curve shows the desire operating range of the 2N2906 for a chosen junction temperature of 150C. However for good design practice and provide for a longer life most designs will elect to operate a either 125C or even 110C to provide even more head-room.
Select the desired junction temperature [below 200C]. Draw a line parallel to one of the curves to determine the functional operation of the 2N2906 over temperature.
