AN2359

Application example nº 1

11/18

3.2

Thermal measurements

In this application, the main thermal issues are related to parasitic capacitance effects that

can lead to higher power dissipation in the device and then higher working temperature. In

order to evaluate the case temperature of the VIPer in the entire input voltage range, a

thermal mapping by means of an IR Camera was done at ambient temperature and full load.

In Figure 12. and Figure 13. the thermal profile of the device at minimum and maximum

input voltage range respectively is shown. It is important to highlight that at low line the

conduction losses are predominant, instead at high input voltage the switch losses became

not negligible, due to parasitic capacitance of the inductor. This is point out in Figure 14.

Figure 10.

Turn on losses measurement at full

Figure 11.

Turn on losses measurement at full

M1 Area 2.92

µWs

M1 Area 10.07

µWs

Figure 12.

VIPer22A Thermal profile: at VIN=

Figure 13.

VIPer22A Thermal profile: at VIN=