Datasheet
DS_DIM3R3400_08142013 E-mail: DCDC@delta.com.tw
http://www.deltaww.com/dcdc
P13
THERMAL CONSIDERATIONS
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’’).
AIR FLOW
MODULE
PWB
50.8(2.00")
AIR VELOCITY
AND AMBIENT
TEMPERATURE
SURED BELOW
THE MODULE
FANCING PWB
Note: Wind Tunnel Test Setup Figure Dimensions are in millimeters and (Inches)
Figure 12: Wind tunnel test setup
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.
THERMAL CURVES
HOT SPOT
AIRFLOW
NTC RESISTOR
Figure 13: * Hot spot& NTC resistor temperature
measured points. The allowed maximum hot spot
temperature is defined at 115
℃
0
1
2
3
4
5
6
7
8
9
25 30 35 40 45 50 55 60 65 70 75 80 85
Output Current (A)
Ambient Temperature (℃)
DIM3R3400SFA Output Current vs. Ambient Temperature and Air Velocity
@Vin = 48V Vout =48V@3.3V/1.5A (Transverse Orientation)
200LFM
100LFM
300LFM
400LFM
Figure 14: Output current vs. ambient temperature and air
velocity @Vin=48V,Vout=48V@3.3V/1.5A (Transverse
Orientation, Airflow from Vin- to Vin+)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
25 30 35 40 45 50 55 60 65 70 75 80 85
Output Current (A)
Ambient Temperature (℃)
DIM3R3400SFA Output Current vs. Ambient Temperature and Air Velocity
@Vin = 48V Vout=3.3V@48V/4A (Transverse Orientation)
200LFM
100LFM
300LFM
Figure 15: Output current vs. ambient temperature and air
velocity @Vin=48V,Vout=3.3V@48V/4A (Transverse
Orientation, Airflow from Vin- to Vin+)