| 1. |
Use a heat sink at all times
with any power module. This heat sink should be of adequate mass to maintain the
power supply's baseplate temperature below its specified maximum temperature.
The following equations assist when designing a suitable heat sink. The basic
equation is: PDiss= Pin-Pout.
When Pout is defined as the maximum load condition and Pin is defined as a function of Pout and efficiency. The
equation is therefore:
PDiss=(Pout/Efficiency) - Pout.
The energy loss calculated from the above equation will be dissipated via the converter's
baseplate the form of heat. A key parameter in this equation is the converter
efficiency. Efficiency will be dependent upon the line and load characteristics of
the application. |
 2. |
Be sure that the mounting surface of the power
supply ("baseplate") and the heatsink are clean and thermal grease is properly
applied. |
| 3. |
Fuse the input to the power module according to the
rating in the appropriate catalog or as shown on the label of the unit (two times low line
input current). |
| 4. |
Follow the wiring or "hook up" information
contained in the catalogs or shown on the label of the power module. |
| 5. |
If sense pins are present (as described in the
catalog or shown on the label) they must be connected either locally (to the respective
"+" or "-" output) or remotely (to the respective "+" or
"-" points of load) for proper operation. |
| 6. |
Use the largest practical wire gauge for all wires
carrying load current and keep them as short as possible (especially if you are utilizing
the sense pins in the "remote" configuration). |
| 7. |
Be sure that any electrical performance
measurements intended to verify published performance are taken as close to the power
module as possible i.e., at the output terminations (for example, ripple measurements
should be taken at the module terminations with the appropriate measurement parameter, 25
or 10 MHz). |
| 8. |
Be sure to utilize a well regulated power source
when testing the power module. This will provide a control measurement. If a
problem arises with system integration you will be able to compare test results for a
given module; i.e., test data from the system source and test data from a controlled
source. |
| 9. |
When verifying electrical performance over
temperature extremes make sure that the reference point is the baseplate of the power
module. For example; measuring the performance of a power module at high temperature
is meaningless if high temperature is defined (or measured) as ambient or case
temperature. If the ambient temperature is measured at +95°C then the baseplate
will be over the maximum of +100°C and permanent damage will occur to the power module. |
| 10. |
The only bad questions are those not asked.
Martek Power Abbott designs and manufactures standard power modules. We maintain a
full staff of applications engineers to respond to customer questions. Please
contact us via this web site or the phone numbers listed for applications assistance. |
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