EPR-48 Datasheet, PDF (11/20 Pages) Power Integrations, Inc. – Engineering Prototype Report for EP48 - 1.4 W Non-Isolated Buck Converter Using LNK304P

02-May-2005
EP48 – 12 V, 1.44 W, Non-Isolated Buck Converter
7.4 Thermal Performance
To verify acceptable thermal performance, thermocouples were placed on key
components on the board and the unit was placed into a thermal chamber. The ambient
was raised to 85 °C with no air flow over the board. The unit was fully loaded and
allowed to stabilize at three different line voltages, at which point temperature
measurements were recorded.
In addition, a thermal image was taken of a unit painted matte black, operating at full
load, 85 VAC and an ambient temperature of 23 °C.
These results show very acceptable temperature rise figures and show that the unit can
operate in a very high ambient with sufficient margin to thermal shutdown.
Figure 8 – Infrared Thermograph of EP48, 85 VAC Input, Full Load and 23 °C Ambient.
Temperature (°C)
Item
90 VAC 115 VAC 240 VAC
Ambient
85
85
85
LinkSwitch-TN (U1)
112
112
106
Output Inductor (L1)
102
103
105
Freewheeling Diode (D1)
103
103
107
Input Capacitor (C5)
95
92
90
Output Capacitor (C2)
90
90
91
Table 2 - Temperature of Key Components, 85 VAC, Full Load, 85 °C Ambient.
Page 11 of 20
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