Data Sheet: Xeta
iHG48070A033V, 3.3V/70A Output Half Brick Series
©2008 TDK Innoveta Inc.
iHG Datasheet 2008-05-15 Revision 1.1
℡
(877) 498-0099
11/16
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 printed circuit boards
(PCBs) or circuit cards in cabinet racks.
The power module is mounted on a 0.087
inch thick, 12-layer, 2oz/layer PCB and is
vertically oriented within the wind tunnel.
Power is routed on the internal layers of the
PCB. The outer copper layers are thermally
decoupled from the converter to better
simulate the customer’s application. This
also results in a more conservative derating.
The cross section of the airflow passage is
rectangular with the spacing between the
top of the module and a parallel facing PCB
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 unit’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 in 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
location
indicated
in
the
thermal
measurement location figure in the Thermal
Performance section for the power module
of interest. In all conditions, the power
module should be operated below the
maximum operating temperature shown on
AIRFLOW
Air Velocity and Ambient Temperature
Measurement Location
A
I
R
F
L
O
W
12.7
(0.50)
Module
Centerline
Air Passage
Centerline
Adjacent PCB
76 (3.0)
Wind Tunnel Test Setup Figure
Dimensions are in millimeters (inches)
