Thermal Consideration; Thermal Derating - Delta Electronics Delphi 6A Series Datasheet

THERMAL CONSIDERATION

Thermal management is an important part of the system
design. To ensure proper, reliable operation, sufficient
cooling of the power module is needed over the entire
temperature range of the module. Convection cooling is
usually the dominant mode of heat transfer.
Hence, the choice of equipment to characterize the
thermal performance of the power module is a wind
tunnel.
Thermal Testing Setup
Delta's DC/DC power modules are characterized in
heated vertical wind tunnels that simulate the thermal
environments encountered
equipment. This type of equipment commonly uses
vertically mounted circuit cards in cabinet racks in which
the power modules are mounted.
The following figure
characterization setup. The power module is mounted
on a test PWB and is vertically positioned within the
wind tunnel. The space between the neighboring PWB
and the top of the power module is constantly kept at
6.35mm (0.25'').

Thermal Derating

Heat can be removed by increasing airflow over the
module. To enhance system reliability, the power
module should always be operated below the maximum
operating temperature. If the temperature exceeds the
maximum module temperature, reliability of the unit may
be affected.
FACING PWB
AIR VELOCITY
AND AMBIENT
TEMPERATURE
MEASURED BELOW
THE MODULE
AIR FLOW
Note: Wind tunnel test setup figure dimensions are in
millimeters and (Inches)
Figure 25: Wind tunnel test setup
DS_NE12S06A_06302008
in most electronics
shows the wind tunnel
PWB
MODULE
50.8 (2.0")
11 (0.43")
22 (0.87")
THERMAL CURVES (VERTICAL)
Figure 26: Temperature measurement location* The allowed
maximum hot spot temperature is defined at 113
NE12S0A0V06(standard) Output Current vs. Ambient Temperature and Air Velocity
Output Current (A)
@Vin=12V Vout=0.9V (Either Orientation)
6
5
4
3
2
1
0
25 30 35 40 45 50
Figure 27: Output current vs. ambient temperature and air
velocity @Vin=12V, Vout=0.9V (Either Orientation)
NE12S0A0V06(standard) Output Current vs. Ambient Temperature and Air Velocity
Output Current (A)
@Vin=12V Vout=2.5V (Either Orientation)
6
5
4
3
2
1
0
25 30 35 40 45 50
Figure 28: Output current vs. ambient temperature and air
velocity @Vin=12V, Vout=2.5V (Either Orientation)
℃
Natural
Convection
100LFM
200LFM
300LFM
400LFM
55 60 65 70 75 80
Ambient Temperature (℃)
Natural
Convection
100LFM
200LFM
300LFM
400LFM
500LFM
55 60 65 70 75 80
Ambient Temperature (℃)
85
85
9