Delta Electronics DNT04 manual Thermal Considerations, Thermal Curves, Thermal Testing Setup

Models: DNT04

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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 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 height of this fan duct is constantly kept at 25.4mm (1’’).

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

Figure 32: Temperature measurement location

The allowed maximum hot spot temperature is defined at 125

DNT04S0A0R03(standard) Output Current vs. Ambient Temperature and Air Velocity

Output Current (A)

@Vin=5V Vout=0.75~3.3V (Through PCB Orientation)

3.5

 

3.0

Natural

Convection

2.5

2.0

1.5

1.0

0.5

0.0

25

30

35

40

45

50

55

60

65

70

75

80

85

 

 

 

 

 

 

 

 

 

 

Ambient Temperature ()

Figure 33: Output current vs. ambient temperature and air velocity @ Vin=5V, Vout=0.75V~3.3V(Through PCB Orientation)

FACING PWB

AIR VELOCITY

AND AMBIENT

TEMPERATURE

MEASURED BELOW

THE MODULE

PWB

MODULE

50.8 (2.0”)

AIR FLOW

Thermal Testing Setup 12.7 (0.5”) Thermal Derating 25.4 (1.0”)

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

Figure 31: Wind tunnel test setup

DS_DNT04SIP3A_09262007

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Delta Electronics DNT04 manual Thermal Considerations, Thermal Curves, Thermal Testing Setup, Thermal Derating