Thermal Consideration - Delta Electronics Delphi ND Series Specification Sheet

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 31: Wind tunnel test setup
DS_ND12S10A_07172008
in most electronics
shows the wind tunnel
PWB
MODULE
50.8 (2.0")
11 (0.43")
22 (0.87")
THERMAL CUREVES
Figure 32: Temperature measurement location* The allowed
maximum hot spot temperature is defined at 124
ND12S0A0V50(standard) Output Current vs. Ambient Temperature and Air Velocity
Output Current (A)
@Vin=12V Vout=0.9V (Through PCB Orientation)
55
50
45
Natural
Convection
40
35
30
25
20
15
10
5
0
25 30 35 40 45
Figure 33: Output current vs. ambient temperature and air
velocity @Vin=12V, Vout=0.9V(Through PCB Orientation)
ND12S0A0V50(standard) Output Current vs. Ambient Temperature and Air Velocity
Output Current (A)
@Vin=12V Vout=2.5V (Through PCB Orientation)
55
50
45
Natural
40
Convection
35
100LFM
30
25
20
15
10
5
0
25 30 35 40 45
Figure 34: Output current vs. ambient temperature and air
velocity@ Vin=12V, Vout=2.5V(Through PCB Orientation)
`
℃
100LFM
200LFM
50 55 60 65 70 75 80
Ambient Temperature (℃)
200LFM
300LFM
50 55 60 65 70 75 80
Ambient Temperature (℃)
85
85
10