Technical Reference Notes (AEH60/ALH60F48)

MODEL: AEH/ALH60F48

SHEET 14 OF 21

SEPTEMBER 26, 2002 - REVISION 02

Thermal Considerations

While the ALH60 (Open Frame Converter) is designed to provide the maximum performance at the lowest profile, the

AEH60 (Power Converter with HS adapter) operates in a variety of thermal environments. Sufficient cooling should be

provided to help ensure reliable operation of either device. Heat generating components are thermally coupled to the

adapter where heat energy is removed by conduction, convection, and radiation to the surrounding environment. Heat sinks

can provide enhanced output performance as shown below. Proper cooling can be verified by measuring the case

temperature (Center of adapter plate/baseplate).

HEAT TRANSFER CHARACTERISTICS

Increasing airflow over the converter enhances heat transfer via convection. Figure 16 shows worse case maximum power

that can be dissipated by the converter, without exceeding the maximum adapter plate temperature, versus local ambient

dissipated through both the adapter plate and through the output pins (unit soldered into a 4” square copper plane (2 Oz.) or

equivalent).

Figure 16. Forced Convection Power Dissipation

Note:

This is worse case dissipation - additional Heat transfer through O/P pins will increase

allowable dissipation considerably. See Figure 17.

AEH60 Series

Power Dissipation vs Temp

Forced Convection without HS

0

5

10

15

20

25

30

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100

Ambient Temperature (ºC)

Nat. Conv.

1.0 m/s (200 ft/min)

1.5 m/s (300 ft/min)

2.0 m/s (400 ft/min)