DER-19

TOP245P Multiple Output Set Top Box

March 30, 2004

Page 3 of 25

Power Integrations, Inc.

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

www.powerint.com

Table Of Figures

Figure 1 – Populated Circuit Board (Scale in cm).............................................................. 4

Figure 2– TOP245P Schematic for 32W cont / 46W peak................................................. 6

Figure 3 – Printed Circuit Layout (Scale not 1:1) ............................................................... 8

Figure 4 –Transformer Electrical Diagram ....................................................................... 10

Figure 5 – Transformer Build Diagram ............................................................................ 11

Figure 6- Full Continuous Power Conversion Efficiency.................................................. 15

Figure 7 - Efficiency Variation with Load ......................................................................... 15

Figure 9 – Line Regulation, Room Temperature, Full Load............................................. 17

Figure 10 - Cross Regulation........................................................................................... 17

Figure 11 - Key Component Temperature Rise variation with Line Voltage .................... 18

Figure 13 - 265 VAC, Full Continuous Load .................................................................... 18

Figure 18 - 265 VAC Input and Maximum Load............................................................... 20

................................................................................................................................. 20

Figure 20 - Oscilloscope Probe Prepared for Ripple Measurement................................. 21

Figure 21 - Oscilloscope Probe with Probe Master 5125BA BNC Adapter...................... 21

Important Notes:

Although this board is designed to satisfy safety isolation requirements, the engineering

prototype has not been agency approved. Therefore, all testing should be performed

using an isolation transformer to provide the AC input to the prototype board.

Design Reports contain a power supply design specification, schematic, bill of materials,

and transformer documentation. Performance data and typical operation characteristics

are included. Typically only a single prototype has been built.