DER-19

TOP245P Multiple Output Set Top Box

March 30, 2004

Page 16 of 25

Power Integrations, Inc.

Tel: +1 408 414 9200 Fax: +1 408 414 9201

www.powerint.com

9.2

No-load Input Power

input.

9.3

Peak Power

The prototype was loaded to the specified peak power levels in Table 1 and the

temperature of the TOP245P monitored. The 46W peak power level can easily be

supplied in 25°C ambient conditions. Under peak power levels, the TOP245P

temperature was measured at 86°C. Thus, a peak power of 46W in 50°C ambient is

achievable and only thermal shutdown will limit the time the peak power can be delivered

for. With the high operating efficiency of this design, peak power levels of above 50W can

be achieved for a few seconds.

9.4

Regulation

9.4.1 Load

-5

0

5

10

15

20

25

0

5

10

15

20

25

30

35

Output Power (W)

3V3

5V

12V

20V