Datasheet

DS_D12S05020_10282008
9
THERMAL CURVES
Figure 31: Temperature measurement location* The allowed
maximum hot spot temperature is defined at 125 ℃
D12S05020-1 B Output Current vs. Ambient Temperature and Air Velocity
@ Vin =12V, Vout =5V (Worse Orientation)
0
5
10
15
20
25
25 35 45 55 65 75 85
Ambient Temperature (℃)
Output Current (A)
200LFM
500LFM
100LFM
300LFM
400LFM
Natural
Convection
Figure 32: Output current vs. ambient temperature and air
velocity @Vin=12V, Vout=5.0V (Worst Orientation)
D12S05020-1 B Output Current vs. Ambient Temperature and Air Velocity
@ Vin =12V, Vout =3.3V (Worse Orientation)
0
5
10
15
20
25
25 35 45 55 65 75 85
Ambient Temperature (℃)
Output Current (A)
100LFM
400LFM
200LFM
300LFM
Natural
Convection
Figure 33: Output current vs. ambient temperature and air
velocity@ Vin=12V, Vout=3.3V (Worst Orientation)
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 in most electronics
equipment. This type of equipment commonly uses
vertically mounted circuit cards in cabinet racks in which
the power modules are mounted.
The following figure shows the wind tunnel
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.
Note: Wind Tunnel Test Setup Figure Dimensions are in millimeters and (Inches)
12.7 (0.5”)
MODULE
A
IR FLOW
50.8
(
2.0”
)
FACING PWB
PWB
AIR VELOCIT
Y
AND AMBIEN
T
TEMPERATURE
MEASURED BELOW
THE MODULE
Note: Wind tunnel test setup figure dimensions are in
millimeters and (Inches)