1N4460 Diode Temperature-Current Derating Curve [Axial Lead]
Zener Voltage Regulator Diode, DO-41 package.
DO-41 Diode Derating Curves
The chart determines how much to power [wattage] to derate based on the operational temperature of the case, or body temperature. Note that the component lead length is provided, which has a lot to do with how well the component conducts heat away from the device via its leads. In general the longer the leads, the greater the resistance to heat transfer.
Guidelines for derating diodes, additional Diode Derating Curves
The above chart details the maximum allowable power dissipation with increasing ambient temperature for an axial leaded DO41 package. Maximum operational power dissipation is achievable up to 500C. However above 500C 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.
Although some of the curves extend past 50C, the safest curve to use is the lowest gray curve which provides the longest life.
Lead length is also important in conducting heat, use the length shown in the graph, 3/8"
Refer to MIL-PRF-19500/406; Semiconductor Device, Diode, Silicon, Voltage Regulator, Types 1N4460, 1N4460C, 1N4460D through 1N4496, 1N4496C, 1N4496D, and 1N6485, 1N6485C, 1N6485D through 1N6491, 1N6491C, 1N6491D, 1N4460US, 1N4460CUS, 1N4460DUS through 1N4496US, 1N4496CUS, 1N4496DUS, and 1N6485US, 1N6485CUS, 1N6485DUS through 1N6491US, 1N6491CUS, 1N6491DUS, Plus C and D Tolerance Suffix; JAN, JANTX, JANTXV, and JANS, [DO-41 Axial Leaded]
1N4460 Maximum Operational Ratings:
Maximum Repetitive Reverse Voltage = xx volts [Device Dependent]
Average Rectified Forward Current = xx mA [Device Dependent]
Power Dissipation 25C = 1.5 Watts
Operating Temperature = -65C to +175C
Zener Diodes covered by this graph:
1.5 watt silicon, low leakage, voltage regulator diodes
1N4460, 1N4461, 1N4462, 1N4463, 1N4464, 1N4465, 1N4466, 1N4467, 1N4468, 1N4469,
1N4470, 1N4471, 1N4472, 1N4473, 1N4474, 1N4475, 1N4476, 1N4477, 1N4478, 1N4479,
1N4480, 1N4481, 1N4482, 1N4483, 1N4484, 1N4485, 1N4486, 1N4487, 1N4488, 1N4489,
1N4490, 1N4491, 1N4492, 1N4493, 1N4494, 1N4495, 1N4496
Zener Voltage, Vz = 3.3v to 200 volts depending on device.
Note that no electrical specifications are provided here, because the DOD document covers a number of devices which all have different characteristics, primarily zener voltage and current. However to many to list here, as the curves are the main topic.