VIEWS: 0 PAGES: 9 POSTED ON: 10/19/2012 Public Domain
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