2N4930 Temperature-Power Derating Curve [2N3743U4, 2N4931U4]
PNP Silicon High Voltage Transistor. Package, TO-39 [Through-Hole].
2N4930 Transistor Operational Power Derating Curve
The chart details the maximum allowable power dissipation with increasing 2N4930 device case 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 2N4930s 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 2N4930 operating power dissipation vs increasing ambient [surrounding] temperature. The graph above depicts the derating of a 2N4930 transistor in a case mounted package.
Use the Graph to determine how much to derate power [wattage] based on ambient operational temperature. Additional Transistor Derating Curves
Temperature derating is a standard design practice to insure that the devices junction temperature never exceeds the maximum number provided in the data sheet.
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]
2N4930 Maximum Operational Ratings:
Collector Emitter Voltage = 3000 volts dc
Power Dissipation 250C = 1 Watt
Operating Temperature = -65 to +2000C
Note that by 200C the 2N4930 must dissipate zero power.
Listing of Transistor Manufacturers and vendors.
How to Derate; Guideline for Derating Electronic Components
--------------------------------------------
