IAF12020A007V-006-R datasheet(14/18 Pages) TDK

14 / 18 page

Advance Data Sheet: iAF Series – Non-isolated SMT Power Module

iAF12_Full_Datasheet_08152011.doc 8/16/2011

(877) 498-0099

14/18

Thermal Management:

An important part of the overall system design process

is thermal management; thermal design must be

considered at all levels to ensure good reliability and

lifetime of the final system. Superior thermal design

and the ability to operate in severe application

environments are key elements of a robust, reliable

power module.

A finite amount of heat must be dissipated from the

power module to the surrounding environment. This

heat is transferred by the three modes of heat

transfer: convection, conduction and radiation. While

all three modes of heat transfer are present in every

application, convection is the dominant mode of heat

transfer in most applications. However, to ensure

adequate cooling and proper operation, all three

modes should be considered in a final system

configuration.

The open frame design of the power module provides

an air path to individual components. This air path

improves convection cooling to the surrounding

environment, which reduces areas of heat

concentration and resulting hot spots.

Test Setup:

The thermal performance data of the

power module is based upon measurements obtained

from a wind tunnel test with the setup shown in the

wind tunnel figure. This thermal test setup replicates

the typical thermal environments encountered in most

modern electronic systems with distributed power

architectures. The electronic equipment in

networking, telecom, wireless, and advanced

computer systems operates in similar environments

and utilizes vertically mounted PCBs or circuit cards in

cabinet racks.

The power module, as shown in the figure, is mounted

on a printed circuit board (PCB) and is vertically

oriented within the wind tunnel. The cross section of

the airflow passage is rectangular. The spacing

between the top of the module and a parallel facing

PCB is kept at a constant (0.5 in). The power

module’s orientation with respect to the airflow

direction can have a significant impact on the

module’s thermal performance.

Thermal Derating

: For proper application of the

power module in a given thermal environment, output

current derating curves are provided as a design

guideline on the Thermal Performance section for the

power module of interest. The module temperature

should be measured in the final system configuration

to ensure proper thermal management of the power

module. For thermal performance verification, the

module temperature should be measured at the

component indicated in the thermal measurement

location figure on the thermal performance page for

the power module of interest. In all conditions, the

power module should be operated below the

maximum operating temperature shown on the

derating curve. For improved design margins and

enhanced system reliability, the power module may be

operated at temperatures below the maximum rated

operating temperature

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 2 m/s

(400 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.

AIRFLOW

Air Velocity and Ambient Temperature

Measurement Location

12.7

(0.50)

Module

Centerline

Air Passage

Centerline

Adjacent PCB

76 (3.0)

Wind Tunnel Test Setup Figure Dimensions are in

millimeters and (inches).

IAF12020A007V-006-R Datasheet(PDF) 14 Page - TDK Electronics

IAF12020A007V-006-R Datasheet(HTML) 14 Page - TDK Electronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Datasheet Download

Link URL