calc_thermal

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					                                                                                    Thermal Curve Calculator



Select desired Heatsink Part # (RoHS / non-RoHS) or Product type:

                                                              Choose device                                                                         This Calculator assumes the efficien
                                                                                                                                                  constant over all line and load condition
This is for a:                                                                                                                                         world this is not the case. Please v
                                                                                                                                                   efficiency if your application deviates
                                                                                                                                                     from nominal. Verify all thermal man
Enter Device's Maximum Output Power in Watts:                                                                            1                                        designs experimentally.
Enter Minimum Expected Efficiency in %:                                                                                  1

                                                                                            Thermal Curves for Selected Item               0.01
                                                                                    (Not All Curves in the Legend are Available for All Items)
                                            1

Ambient Temperature                                           Power Limit                   Free Air        100  200
                                                                                                       50 LFM LFM LFM 250 LFM 400 LFM              600
                                                                                                                                           500 LFM LFM750 LFM
                                 1                                                          #DIV/0!    #### ##### #DIV/0! #DIV/0! #DIV/0! ##### #DIV/0! #####
                                             5                                              #DIV/0!    #### ##### #DIV/0! #DIV/0! #DIV/0! ##### #DIV/0! #####
                                 1          10                                              #DIV/0!    #### ##### #DIV/0! #DIV/0! #DIV/0! ##### #DIV/0! #####
                                            15                                              #DIV/0!    #### ##### #DIV/0! #DIV/0! #DIV/0! ##### #DIV/0! #####
                                 1          20                                              #DIV/0!    #### ##### #DIV/0! #DIV/0! #DIV/0! ##### #DIV/0! #####
 Maximum Power Output in Watts




                                            25                                              #DIV/0!    #### ##### #DIV/0! #DIV/0! #DIV/0! ##### #DIV/0! #####
                                 1          30                                              #DIV/0!    #### ##### #DIV/0! #DIV/0! #DIV/0! ##### #DIV/0! #####
                                            35                                              #DIV/0!    #### ##### #DIV/0! #DIV/0! #DIV/0! ##### #DIV/0! #####
                                 1
                                            40                                              #DIV/0!    #### ##### #DIV/0! #DIV/0! #DIV/0! ##### #DIV/0! #####
                                            45                                              #DIV/0!    #### ##### #DIV/0! #DIV/0! #DIV/0! ##### #DIV/0! #####
                                 1
                                            50                                              #DIV/0!    #### ##### #DIV/0! #DIV/0! #DIV/0! ##### #DIV/0! #####
                                            55                                              #DIV/0!    #### ##### #DIV/0! #DIV/0! #DIV/0! ##### #DIV/0! #####
                                 0
                                            60                                              #DIV/0!    #### ##### #DIV/0! #DIV/0! #DIV/0! ##### #DIV/0! #####
                                 0
                                            65                                              #DIV/0!    #### ##### #DIV/0! #DIV/0! #DIV/0! ##### #DIV/0! #####
                                            70                                              #DIV/0!    #### ##### #DIV/0! #DIV/0! #DIV/0! ##### #DIV/0! #####
                                 0          75                                              #DIV/0!    #### ##### #DIV/0! #DIV/0! #DIV/0! ##### #DIV/0! #####
                                            80                                              #DIV/0!    #### ##### #DIV/0! #DIV/0! #DIV/0! ##### #DIV/0! #####
                                 0          85                                              #DIV/0!    #### ##### #DIV/0! #DIV/0! #DIV/0! ##### #DIV/0! #####
                                            90                                              #DIV/0!    #### ##### #DIV/0! #DIV/0! #DIV/0! ##### #DIV/0! #####
                                 0          95                                              #DIV/0!    #### ##### #DIV/0! #DIV/0! #DIV/0! ##### #DIV/0! #####
                                     0   5 100 10   15   20      25       30   35                45
                                                                                         40 #DIV/0!    #### ##### #DIV/0! 65
                                                                                                       50     55   60            70     75      80     85   90
                                                                                                                           #DIV/0! #DIV/0! ##### #DIV/0! #####



                                                                                             Page 1
Thermal Curve Calculator


            Ambient Temperature in
                    Deg C




        Page 2
                                                   Thermal Curve Calculator




alculator assumes the efficiency remains
 over all line and load conditions. In the real
d this is not the case. Please verify the
cy if your application deviates significantly
nominal. Verify all thermal management
       designs experimentally.




              800 LFM1000 LFM1200 LFM
              #DIV/0! #DIV/0! #DIV/0!
              #DIV/0! #DIV/0! #DIV/0!
              #DIV/0! #DIV/0! #DIV/0!Free Air
              #DIV/0! #DIV/0! #DIV/0!50 LFM
              #DIV/0! #DIV/0! #DIV/0!100 LFM
              #DIV/0! #DIV/0! #DIV/0!
                                     200 LFM
              #DIV/0! #DIV/0! #DIV/0!
              #DIV/0! #DIV/0! #DIV/0!250 LFM
              #DIV/0! #DIV/0! #DIV/0!400 LFM
              #DIV/0! #DIV/0! #DIV/0!500 LFM
              #DIV/0! #DIV/0! #DIV/0!600 LFM
              #DIV/0! #DIV/0! #DIV/0!750 LFM
              #DIV/0! #DIV/0! #DIV/0!800 LFM
              #DIV/0! #DIV/0! #DIV/0!
                                     1000 LFM
              #DIV/0! #DIV/0! #DIV/0!
                                     1200 LFM
              #DIV/0! #DIV/0! #DIV/0!
              #DIV/0! #DIV/0! #DIV/0!Power Limit
              #DIV/0! #DIV/0! #DIV/0!
              #DIV/0! #DIV/0! #DIV/0!
              #DIV/0! #DIV/0! #DIV/0!
                  95    100
           90 #DIV/0! #DIV/0! #DIV/0!




                                                           Page 3
Thermal Curve Calculator




        Page 4
                                            Instructions and Cautions




    1      Choose a heatsink, bare module or product from the pull down menu
           The program returns the intended module size for 2nd gen as MAXI, MINI, MICRO and
           VI-200, VI-J00 or number of internal modules for 1st gen.
    2      If prompted about front end module enter Y or N in the green box.
    3      Enter the device's maximum power rating in the space provided
    4      Enter the device's efficiency rating for the intended operating parameters in the space provided

The calculator determines the theoretical maximum power which can be delivered to the load
based upon the module baseplate maximum rated temperature, the thermal impedance from the
baseplate to the surrounding and the efficiency of the converter.

It limits the maximum power to the load to the module's package size maximum power rating +15% as this is where the
current limit feature normally gets activated. You will note in some cases that the curves "bend" at the
limit. This is due to limitations in the charting feature of Excel. In reality all the traces are linear.

In all cases the area above the "Power Limit" line to the maximum is a "ratings exceeded" zone
and applications should not be designed around data from this area.

For applications which push the limit use caution, for example a micro with no heatsink in free air at an ambient of 50C
and an efficiency of 75% nominal the maximum power output is shown to be ~12W.
This assumes the efficiency remained constant from the nominal load to the 12W load. In reality
the efficiency at 12W will be lower than the nominal published data.

Thermal data taken with ThermMate interface material.

Every effort has been made to make this tool accurate, however, mistakes do happen.
VERIFY ALL THERMAL MANAGEMENT SYSTEMS EXPERIMENTALLY




                                                     Page 5
                               Instructions and Cautions




space provided




ng +15% as this is where the




ree air at an ambient of 50C




                                        Page 6
Heatsink #      Natural         50 LFM
30089 / 02111             3.4
                                     Thermal Impedance Deg C/W
100 LFM   200 LFM         250 LFM   400 LFM     500 LFM    600 LFM     750 LFM   800 LFM
                    1.5                       1                    0.8                     0.6
1000 LFM         1200 LFM
           0.5              0

				
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posted:10/19/2012
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