EPR-91 Datasheet, PDF (3/36 Pages) Power Integrations, Inc. – Engineering Prototype Report for EP-91 - 12 W Power Supply using

7-Feb-2006
EP-91 12 V, 1 A, Universal Input Supply
Table Of Contents
1 Introduction................................................................................................................. 5
2 Power Supply Specification ........................................................................................ 6
3 Circuit Diagram........................................................................................................... 7
4 Circuit Description ...................................................................................................... 8
4.1 Input Rectification and Filtering ........................................................................... 8
4.2 TNY278P Operation ............................................................................................ 8
4.3 Output Rectification and Filtering ........................................................................ 9
4.4 Feedback and Output Voltage Regulation........................................................... 9
4.5 Output Overvoltage Shutdown ............................................................................ 9
4.6 EMI Design Aspects ............................................................................................ 9
4.7 Peak Primary Current Limit Selection................................................................ 10
4.8 UV Lockout........................................................................................................ 10
5 PCB Layout .............................................................................................................. 11
6 Bill Of Materials ........................................................................................................ 12
7 Transformer Specification......................................................................................... 13
7.1 Electrical Diagram ............................................................................................. 13
7.2 Electrical Specifications..................................................................................... 13
7.3 Materials............................................................................................................ 14
7.4 Transformer Build Diagram ............................................................................... 14
7.5 Transformer Construction.................................................................................. 15
8 Transformer Spreadsheet......................................................................................... 16
9 Performance Data .................................................................................................... 18
9.1 Efficiency........................................................................................................... 18
9.2 Active Mode CEC Measurement Data............................................................... 19
9.3 No-load Input Power (R8 not installed: no bias winding supplementation)........ 20
9.4 No-load Input Power (with R8 and bias winding supplementation) ................... 20
9.5 Available Standby Output Power....................................................................... 21
9.6 Regulation ......................................................................................................... 22
9.6.1 Load and Line ............................................................................................ 22
10 Thermal Performance ............................................................................................... 23
11 Waveforms............................................................................................................... 24
11.1 Drain Voltage and Current, Normal Operation .................................................. 24
11.2 Output Voltage Start-Up Profile......................................................................... 25
11.3 Drain Voltage and Current Start-Up Profile ....................................................... 25
11.4 Load Transient Response (75% to 100% Load Step) ....................................... 26
11.5 Output Ripple Measurements............................................................................ 27
11.5.1 Ripple Measurement Technique ................................................................ 27
11.5.2 Measurement Results ................................................................................ 28
11.6 Overvoltage Shutdown ...................................................................................... 28
12 Line Surge................................................................................................................ 29
13 Conducted EMI ........................................................................................................ 30
13.1 115 VAC, Full Load ........................................................................................... 30
13.2 230 VAC, Full Load ........................................................................................... 31
14 Audible Noise........................................................................................................... 32
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