TDK iHA48040A033V* specifications 13/17

Data Sheet: Veta® iHA48040A033V*, 3.3V/40A Output Half Brick Series

Heat transfer by convection can be enhanced by increasing the airflow rate that the power module experiences. The maximum output current of the power module is a function of ambient temperature

(TAMB) and airflow rate as shown in the thermal performance figures on the thermal

performance page for the power module of interest. The curves in the figures are shown for natural convection through 3 m/s (600 ft/min). The data for the natural convection condition has been collected at 0.3 m/s (60 ft/min) of airflow which is the typical airflow generated by other heat dissipating components in many of the systems that these types of modules are used in. In the final system configurations, the airflow rate for the natural convection condition can vary due to temperature gradients from other heat dissipating components.

Heatsink Usage: For applications with demanding environmental requirements, such as higher ambient temperatures or higher power dissipation, the thermal performance of the power module can be improved by attaching a heatsink or cold plate. The iHx platform is designed with a base plate with four M3 X 0.5 through- threaded mounting fillings for attaching a heatsink or cold plate. The addition of a heatsink can reduce the airflow requirement and ensure consistent operation and extended reliability of the system. With improved thermal performance, more power can be delivered at a given environmental condition.

Standard heatsink kits are available from TDK Innoveta for vertical module mounting in two different orientations (longitudinal – perpendicular to the direction of the pins and transverse – parallel to the direction of the pins). The heatsink kit contains four M3 x

0.5steel mounting screws and a precut thermal interface pad for improved thermal resistance between the power module and the heatsink. The screws should be installed using a torque-limiting driver set between

0.35and 0.55 Nm (3-5 in-lbs).

During heatsink assembly, the base-plate to heatsink interface must be carefully managed. A thermal pad may be required to reduce mechanical-assembly-related stresses and improve the thermal connection. Please contact TDK Innoveta Engineering for recommendations on this subject.

The system designer must use an accurate estimate or actual measurement of the internal airflow rate and temperature when doing the heatsink thermal analysis. For each application, a review of the heatsink fin orientation should be completed to verify proper fin alignment with airflow direction to maximize the heatsink effectiveness. With respect to TDK Innoveta standard heatsinks, contact TDK Innoveta for the latest performance data.

©2007 TDK Innoveta Inc.	' (877) 498-0099
iHA Datasheet 040207	13/17