©2007 TDK Innoveta Inc.
iHA Datasheet 040207
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(877) 498
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0099
11/17
Thermal Performance (continued): 0
5
10
15
20
25
30
35
40
107 108 109 110 111 112 113 114
Temperature (oC)
Output Current (A)
1/4" HS 1/2" HS 1" HS
0
5
10
15
20
25
30
35
40
105 106 107 108 109
Temperature (oC)
Output Current (A)
1/4" HS 1/2" HS 1" HS
iHA48040A033V-001 with heatsink maximum Output
Current vs. maximum allowable IMS Temperature at
nominal input voltage with airflow from output to input.
iHA48040A033V-001 with heatsink maximum Output Current
vs. maximum allowable IMS Temperature at nominal input
voltage with airflow from input to output.
Example: : To estimate the maximum temperature at which an iHA48040A033V* Module can
provide full load with 0.5 m/s (100 lfm) of airflow, at nominal line (48V) using a 1/2” heatsink with
the best orientation, one must first look at the Power Dissipation vs. input voltage and Output
Current plot. From this plot, it can be seen that the iHA dissipates 11.5W* of power (Pd) at full
load. From the Case to Ambient Thermal Resistance vs. Airflow Rate curve, Rca is 2.4oC/W. From
the Output Current vs. maximum allowable IMS Temperature plot for the best orientation heatsink
application, it can be seen that the maximum allowable IMS temperature at the thermal
measurement location (Tc) is 112oC. From the governing equation for the overall thermal
resistance of the module, Tc - Ta = Pd x Rca, the maximum ambient temperature (Ta) is determined
to be 84oC.
Complete thermal de-rating and maximum IMS temperature curves without or with a heatsink
((¼”, ½” or 1”) are available upon request from TDK Innoveta.
* Please note that the Power Dissipation curve is for Tamb = 25oC. At higher temperatures, power
dissipation may be higher. Consult with TDK Innoveta if operating at high ambient temperatures.
The thermal curves provided are based upon measurements made in TDK Innoveta’s experimental test setup that is
described in the Thermal Management section. Due to the large number of variables in system design, TDK Innoveta
recommends that the user verify the module’s thermal performance in the end application. The critical component
should be thermo-coupled and monitored, and should not exceed the temperature limit specified in the derating curve
above. It is critical that the thermocouple be mounted in a manner that gives direct thermal contact otherwise significant
measurement errors may result.