2N3634 Temperature-Power Derating Curve [2N3635, 2N3636, 2N3637]
PNP High Voltage Transistor. Package, TO-39, TO-5 Metal Can.
2N3634 Applications -
2N3634 Transistor Temperature-Power Derating Curve
The above chart details the maximum allowable power dissipation with increasing ambient temperature. Maximum operational power dissipation is achievable at 25C. However above 25C the maximum package dissipation, or power, must be reduce to insure that the devices junction temperature remains constant. The higher the ambient temperature is increased the lower the allowable power dissipation, as depicted in the curves.
Decreasing a devices operational limits as temperature is increased is called derating, in this case derating a devices operational power dissipation vs increasing ambient [surrounding] temperature. This particular graph depicts the derating of a 2N3634 transistor in a TO-39 package.
Additional Transistor Derating Curves for other devices [PNP devices].
Temperature derating is a common practice with transistor circuit design.
Refer to MIL-PRF-19500/357K; Semiconductor Device, Transistor, PNP, Silicon, Amplifier, Types 2N3634 through 2N3637, 2N3634UB through 2N3637UB, 2N3634L through 2N3637L, JAN, JANTX, JANTXV, JANS, JANSM, JANSD, JANSP, JANSL, JANSR, JANSF, JANSG, JANSH, JANHCA, JANKCA, JANKCAM, JANKCAD, JANKCAP, JANKCAL, JANKCAR, JANKCAF, JANKCAG, and JANKCAH, [TO-39, TO-5]
2N3634 Maximum Ratings:
Collector Emitter Voltage = 140 volts dc
Collector Base Voltage = 140 volts dc
Emitter Base Voltage = 5 volts dc
Collector Current = 1 amp dc
Power Dissipation 250C = 1 Watt
Operating Temperature = -65 to +2000C
Storage Temperature = -65 to +2000C
Related; 2N3637 Maximum Safe Operating Area
Listing of Transistor Manufacturers
How to Derate; Guideline for Derating Electronic Components
Department of Defense Specifications:
MIL-PRF-19500; Semiconductor Devices, General Specification
Department of Defense Standards:
MIL-STD-750; Test Methods for Semiconductor Devices
