Delta Electronics Series H48SV Thermal Considerations, Thermal Derating, Thermal Testing Setup

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THERMAL CONSIDERATIONS

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 Derating

Heat can be removed by increasing airflow over the module. The module’s maximum case temperature is +100°C. 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 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’’).

FACING PWB

AIR VELOCITY

AND AMBIENT

TEMPERATURE

MEASURED BELOW

THE MODULE

PWB

MODULE

50.8 (2.0”)

AIR FLOW

Thermal Derating 12.7 (0.5”)

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

Figure 24: Wind Tunnel Test Setup

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Contents FEATURES OPTIONSAPPLICATIONS DATASHEET DSH48SV0502008102007TECHNICAL SPECIFICATIONS INPUT CHARACTERISTICSOUTPUT CHARACTERISTICS DYNAMIC CHARACTERISTICSELECTRICAL CHARACTERISTICS CURVES For Negative Remote On/Off Logic For Positive Remote On/Off LogicFigure 8 Output voltage response to step-change in load current 50%-75%-50% of Imax dI/dt = 0.1A/µs.Vin=48V. Load cap 10µF, tantalum capacitor and 1µF ceramic capacitor. Top trace Vout 100mV/div, Bottom trace Iout 5A/div. Scope measurement should be made using a BNC cable length shorter than 20 inch. Position the load between 51 mm and 76 mm 2 inches and 3 inches from the module Copper Strip SCOPELOAD OUTPUT VOLTAGE Vin=48VLOAD CURRENT A THERMAL CURVES NO HEATSINK Figure 19 Power dissipation vs. ambient temperature and airFigure 18 Output current vs. ambient temperature and air velocity V in=75VSafety Considerations Soldering and Cleaning ConsiderationsDESIGN CONSIDERATIONS Input Source ImpedanceFEATURES DESCRIPTIONS Over-Current ProtectionOver-Voltage Protection Over-Temperature ProtectionFEATURES DESCRIPTIONS CON Output Voltage Adjustment TRIMThermal Testing Setup THERMAL CONSIDERATIONSThermal Derating Pin Specification MECHANICAL DRAWINGName FunctionWARRANTY PART NUMBERING SYSTEMMODEL LIST EFF @ 100% LOAD
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