1N4150 Diode Temperature-Current Derating Curve [DO-35 Through-Hole Case, DO-213]
High Conductance Ultra Fast Diode.
1N4150 general applications; High speed switch and general purpose use in computer and industrial applications.
Temperature-Current Derating Curve 1N4150 Diode
Use the Curves to determine how much to derate current based on operational Printed Circuit Broad Temperature [Tpcb]. Note that the graph provides DC Forward Current vs Printed Circuit Board [PCB] temperature. The graph is for still-air with no near-by heat generating components.
Some data sheets indicate to derate above 250C ambient air temperature, at 3.33mW/0C. In either case the best way to draw heat away from the 1N4150 is to provide large pads on the PCB, the larger the better. The larger the copper pad the lower the thermal impedance, as seen in this graph: Copper Thermal Resistance.
Guidelines for derating diodes, additional Diode Derating Curves
Temperature derating is a common design practice for electrical engineers.
Refer to MIL-PRF-19500/231; Silicon Switching Semiconductor Device, Diode Types 1N4150-1, 1N4150UR-1, 1N4150UB, 1N4150UBCA, 1N4150UBCC, 1N4150UBD, and 1N3600, JAN, JANTX, and JANTXV, [DO-35, DO-7, DO-213AA packages]
1N4150 Maximum Operational Ratings:
Maximum Repetitive Reverse Voltage = 50 volts
Average Rectified Forward Current = 200 mA
Power Dissipation 250C = 500mW
Operating Temperature = -65 to +200 0C, [Storage Temperature -65 to +200 0C]
DO-35 Through Hole, Axial Mounting Style
1N4150UB SMD Diode
The other style covered in the specification is the so-called UB version. The UB term is a DOD term used to describe this package, primarily because there is no commercial standard that defines the physical package type.
UB Surface Mount Package
Note the difference between the pin outs or configurations between the UB and UBCC.
The UBCC version has either a common cathode or dual diode configuration.
The UBCA has a common anode orientation or a single diode approach.
The surface mount package remains the same regardless of the diode orientation.
1N4150UB/1N4150UBCA Diode Schematic
1N4150UBD/1N4150UBCC Diode Schematic
This page complements the through hole, axial lead 1N4150 diode. As with that page these devices are selected for extended military temperature ranges, so this surface mount version is not the standard three pin molded plastic component common with commercial implementations of the device. This version has a ceramic body with a metal lid and is qualified to the DOD standard referenced above.
In other words, don't except to see this component being used in a normal design. However the reverse is also true, in that a military design may require the use of this part, or a part qualified for military designs [by military specifications]. Using a 1N4150-UB may be the only option if plastic components are forbidden by the contract.