Datasheet
Data Sheet: Asceta
TM
 iQG Series –Single Output Quarter Brick 
© 2001 - 2012 TDK Innoveta Inc. 
iQG 12V/33A Droop Load Share Rev 1.4 2/15/2012 
(
877
)
 498-0099
11/15 
Wind Tunnel Test Setup Figure
Dimensions are in millimeters and (inches). 
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 
component indicated in the thermal 
measurement location figure on the thermal 
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) 










