This topic covers the 2N6306 in one of 3 different style component packages as described.
2N6306 in a TO-3 Package
2N6306 Temperature-Power Derating Curve
NPN Power Transistor. Package, TO-3 metal Can or TO-254AA, or TO-257AA.
2N6306 applications; High voltage inverters, Switching regulators, Amplifiers
2N6306 Transistor Derating Curve, [TO-3]
The above chart details the maximum allowable power dissipation with increasing case [Tc] temperature for a 2N6306 [or 2N6308] in a TO-3 package. 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. However below 25C the 2N6306 does not require any derating, down to it's minimum operating temperature of -65C.
The higher the ambient temperature [or case 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 case [ambient] temperature. This particular graph depicts the derating of a 2N6306 transistor in a TO-3 package.
An alternate method of derating; linear derating factor average = 0.833 W/0C, above 25C.
Attach a heat sink to increase the device's operating temperature range. Or apply forced air cooling to dissipate the heat, the chart is for still air [no fan].
For longest life use the two bottom 'gray' lines. The top 'black' line represents maximum junction temperature, while the dashed line represents thermal break-down. Other terms for thermal break-down include Electrical Over-stress and Thermal Runaway [Definition].
Refer to MIL-PRF-19500/498; Semiconductor Silicon Device, NPN Power Transistor: [JAN, JANTX, and JANTXV qualification levels]
Package Types 2N6306 & 2N6308 [TO-3].
2N6306T1 & 2N6308T1 [TO-254AA].
2N6306T3 & 2N6308T3 [TO-257AA].
Note that the 2N6306, 2N6306-T1, and 2N6306-T3 are all the same semiconductor in a different package. The same is true for the 2N6308 and the T1 and T3 suffixes, the same semiconductor in a different physical package.
The electrical characteristics provided below are the same for each device regardless of the package style, except where noted.
2N6306 Maximum Ratings:
Collector Emitter Voltage = 250 volts
Collector Base Voltage = 500 volts [2N6306]
Collector Base Voltage = 700 volts [2N6308]
Emitter Base Voltage = 8.0 volts
Base Current = 8.0 Amps DC
Collector Current = 4.0 Amps DC
Power Dissipation 250C = 125 Watts [TO-257]
Power Dissipation 250C = 125 Watts [TO-3]
Power Dissipation 250C = 175 Watts [TO-254]
2N6306 Operating Temperature = -65 to +2000C
2N6306 Storage Temperature = -65 to +2000C
2N6308 Maximum Ratings:
Collector Emitter Voltage = 350 volts
Collector Base Voltage = 700 volts
Emitter Base Voltage = 8.0 volts
Base Current = 8.0 Amps DC
Collector Current = 4.0 Amps DC
Power Dissipation 250C = 125 Watts [TO-3]
2N6308 Operating Temperature = -65 to +2000C [Tj]
2N6308 Storage Temperature = -65 to +2000C [Tstg]
Diamond Case mount TO-3 device is a type of package outline which provides a method of readily attaching one surface of the semiconductor device to a heat dissipater to achieve thermal management of the case temperature. The TO-3 is also called a Flange Mount package because of the shape of the package, which uses the flange as the attachment point.
2N6306 in a TO-254 Package
The part number 2N6306-T1 designates that the device resides within a TO-254 package. The TO-254 is one of three possible options provided for in the specification noted above. Except for the different in maximum power, as noted, the electrical specifications are identical to the 2N6306 in the TO-3 package. However there is difference in the power rating. In comparison to the TO-257, the TO-254 package is slightly larger, and has a larger metal tab.
2N6306T1 Transistor Derating Curve, [TO-254]
2N6306 in a TO-257 Package
The part number 2N6306-T3 designates that the device resides within a TO-254 package. The TO-257 package is one of three possible options provided for in the spec. Except for the different in maximum power, as noted, the electrical specifications are identical to the 2N6306 in the TO-3 package and 2N6306 in a TO-254 package. However there is difference in the power rating, as seen in the curve below.
2N6306T3 Transistor Derating Curve, [TO-257]
At first look each of the three curves look the same. But each component is causing a shift in the maximum DC power dissipation at 25 degrees centigrade.
