DER-37
16W Adapter using TOP245P
April 27, 2004
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
External Ambient
Bridge (BR1)
90 VAC
45
265VAC
45
84
74
Transformer (T1)
Rectifier (D1)
81
87
120
110
122
112
TOP245P (U1)
11.2 Thermal margin test
As a test of thermal margin, the unit was operated at 10o above max rated external
ambient, or 55oC. The unit did not go into thermal shutdown. This implies plenty of
thermal margin.
Power Integrations
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