Delta Electronics Q48SR manual Thermal Considerations, Thermal Curves, Thermal Testing Setup

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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’’).

Thermal Derating

Heat can be removed by increasing airflow over the module. The module’s maximum device temperature is 114 and the measured location is illustrated in Figure

24.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

Figure 24: Hot spot location

The allowed maximum hot spot temperature is defined at 114

FACING PWB

AIR VELOCITY

AND AMBIENT

TEMPERATURE

MEASURED BELOW

THE MODULE

PWB

MODULE

50.8 (2.0”)

AIR FLOW

12.7 (0.5”)

Note: Wind Tunnel Test Setup Figure Dimensions are in millimeters and (Inche

Figure 23: Wind tunnel test setup

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Contents Features Parameter Technical SpecificationsElectrical Characteristics Curves Typical input characteristics at room temperature Electrical Characteristics Curves Output voltage noise and ripple measurement test setup Vin=48V Input Source Impedance Design ConsiderationsFeatures Descriptions Output Voltage Adjustment Trim Features Descriptions CONThermal Derating Thermal Testing SetupThermal Considerations Thermal CurvesThermal Curves CON Pin No Name Function Mechanical DrawingModel List Part Numbering System