2N1613 Transistor Derating Guide Curve

2N1613 Temperature-Power Derating Curve [Thermal Resistance 1750C/W]
Medium Power Silicon N-P-N Planar Transistor. Package, TO-18 metal Can.
2N1613 Applications: High-speed Switching and DC Amplifiers, Audio, Medium current

2N1613 Transistor Derating Curve at ambient temperature

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 2N1613 junction temperature remains constant. The higher the ambient temperature is increased the lower the allowable power dissipation, as depicted in the curves. Decreasing the 2N1613 operational limits as temperature is increased is called derating, in this case derating a devices operational power dissipation vs increasing ambient [surrounding] temperature. This graph depicts the derating of a 2N1613 transistor in a TO-18 package at ambient temperature. Other curves may depict different ratings based on Case Temperature [Tcase].
Derating Equation; Derate linearly at 17.2mW/ degree C above 250C.
Additional Transistor Derating Curves for other devices.

Refer to MIL-PRF-19500/181; Semiconductor Device, Transistor, NPN, Silicon, Low Power, Types 2N718A, 2N1613, and 2N1613L, JAN qualified [TO-18, TO-39, TO-5]

TO-39 Transistor Package

2N1613 Maximum Ratings:
Collector Emitter Voltage = 30 volts [Vceo]
Collector Base Voltage = 75 volts [Vcbo]
Emitter Base Voltage = 7 volts [Vebo]
Collector Current = 500mA [Ic]
Power Dissipation 250C = 800mW [T-ambient]
Operating Temperature = -65 to +2000C
Storage Temperature = -65 to +2000C [Tstg]
Maximum Junction Temperature = 2000C [Tj]

Design note; because the Maximum Junction Temperature is 200 degrees C,
the maximum Operating Temperature also has to be 200C.
Also no power can be consumed at 200C or the junction temperature would be exceeded.

2N718 Pulse Response Test Circuit

The schematic shown above details the test setup to measure the pulse response for the 2N1613 transistor or the 2N718 transistors. The input test pulse is a +/- 1 volt square-wave with a 15nS pulse width, the output is +18 to +20 DC volts.
Note the use of the 1N3064 bias diode [Small Signal], and the different bias voltages used.

Department of Defense Specifications:
MIL-PRF-19500: Semiconductor Devices, General Specification
MIL-STD-750: Test Methods for Semiconductor Devices

Editor note; Board layout and component placement count for a lot. These charts assume no near-by parts generating heat and free air movement. Also large traces or ground planes can assist in removing heat from the metal packages shown, in addition to short component leads.

TO-18 metal Package

TO-5 metal Package

Related Transistor;
2N718 Derating Graph
The 2N718 has a lower power dissipation.

Complete list of NPN Derating Curves.

How-to Derating Electronic Parts

Related Components;
Manufacturers of Transistors & vendors
Component Distributors
Heat Sink Manufacturers [Clip-on, Attachable]