Heat transfer via convection, Thermal considerations – GE Industrial Solutions JRW017-040-060-065-070 Series User Manual

Page 18

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Data Sheet

June 14, 2010

JRW017-070 Series Power Modules DC-DC Converters

36-75Vdc Input; 1.2Vdc to 12Vdc Output

LINEAGE

POWER

18

Thermal Considerations

The power modules operate in a variety of thermal
environments; however, sufficient cooling should be
provided to help ensure reliable operation.

Considerations include ambient temperature, airflow,
module power dissipation, and the need for increased
reliability. A reduction in the operating temperature of
the module will result in an increase in reliability. The
thermal data presented here is based on physical
measurements taken in a wind tunnel.

Heat-dissipating components are mounted on the
topside of the module. Heat is removed by
conduction, convection and radiation to the
surrounding environment. Proper cooling can be
verified by measuring the thermal reference

temperature (T

ref

). The peak temperature (T

ref

)

occurs at the position indicated in Figures 50 - 52.
The temperature at any one of these locations should
not exceed per below table to ensure reliable
operation of the power module.

Figure 50. T

ref

Temperature Measurement

Location for Vo= 12V.

Please refer to the Application Note “Thermal
Characterization Process For Open-Frame Board-
Mounted Power Modules” for a detailed discussion of
thermal aspects including maximum device
temperatures.

Figure 51. T

ref

Temperature Measurement

Location for Vo= 5V.

Figure 52. T

ref

Temperature Measurement

Locations for Vo= 3.3V – 1.2V.

The output power of the module should not exceed
the rated power for the module as listed in the
Ordering Information table.

Although the maximum T

ref

temperature of the power

modules is approximately 117 °C, you can limit this
temperature to a lower value for extremely high
reliability.

Heat Transfer via Convection

Increased airflow over the module enhances the heat
transfer via convection. Following derating figures
shows the maximum output current that can be
delivered by each module in the respective orientation
without exceeding the maximum T

ref

temperature

versus local ambient temperature (T

A

) for natural

convection through 2m/s (400 ft./min).

Model

Device

Temperature( ºC)

JRW070A0P (1.2V)

T

ref3

117

JRW070A0M (1.5V)

T

ref2

/ T

ref3

115/118

JRW065A0Y (1.8V)

T

ref3

115

JRW065A0G (2.5V)

T

ref2

/ T

ref3

117/118

JRW060A0F (3.3V)

T

ref1

/ T

ref2

117/118

JRW040A0A (5V)

T

ref1

117

JRW017A0B (12V)

T

ref1

117

T

ref1

T

ref3

T

ref1

T

ref2

T

ref1

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