DER-37

16W Adapter using TOP245P

April 27, 2004

Page 21 of 32

Power Integrations

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11 Thermal Performance

11.1 Thermal measurements at max ambient

The power supply was placed inside a mock-up plastic case of the specified dimensions.

The case was placed inside a large closed carton box, and the carton was placed in an

oven. The carton box was to prevent airflow on the unit under test. The ambient

temperature was monitored inside the carton. The internal temperatures stabilized after

1 hour of continuous full load operation.

Temperature (

°C)

Item

90 VAC

265VAC

External Ambient

45

45

Bridge (BR1)

84

74

Transformer (T1)

81

87

Rectifier (D1)

120

122

TOP245P (U1)

110

112

11.2 Thermal margin test

As a test of thermal margin, the unit was operated at 10

ambient, or 55

thermal margin.