How do you calculate derating factor?
Clearly, the longer the length of cable enclosed in the insulation the greater will be the derating effect….
| Table 4.5 – Derating factors (CI) for cables up to 10mm² in cross-sectional area buried in thermal insulation. | |
|---|---|
| Length in insulation (mm) | Derating factor (CI) |
| 100 | 0.81 |
| 200 | 0.68 |
| 400 | 0.55 |
How to calculate diode derating guide lines based on temperature?
Diode Temperature Correction Diode Type Critical Stress Parameter Derating Factor General Purpose, Rectifier, Switching, . PIV 0.70 General Purpose, Rectifier, Switching, . Surge Current 0.50 General Purpose, Rectifier, Switching, . Forward Current 0.50 Varactor Power 0.50
What should be the maximum junction temperature of a diode?
The point is to never exceed the maximum junction temperature of the device. The link [above] to derating curves should be taken as a ruled as those pages provide precise Current-Temperature curves over ambient temperature, or in some cases give the derating equation from the data sheet.
How does the body of a diode lose heat?
The terminals of an axial leaded package may be used to conduct heat away from the diode and into the printed wiring board, using the copper pads as a heat dissipator, while the body of the diode will lose heat by convection and radiation into the surrounding air. The point is to never exceed the maximum junction temperature of the device.
Is there such a thing as a design derating table?
While engineering departments may not have a design derating recommendation at all and just leave it up to the engineer. This particular table was derived from NASA recommendations for circuit design. Some engineers use the term Stress Ratio instead of Dearting Factor, but they both mean about the same thing.