DER-56
UPS Battery Charger - LNK520
April 20, 2005
Table Of Contents
1
2
3
4
Introduction.................................................................................................................3
Power Supply Specification........................................................................................4
Schematic...................................................................................................................5
Circuit Description ......................................................................................................6
4.1
Input EMI Filtering...............................................................................................6
LinkSwitch Primary and Output Feedback ..........................................................6
Output Rectification.............................................................................................7
Output Feedback.................................................................................................7
4.2
4.3
4.4
5
6
7
PCB Layout ................................................................................................................8
Bill Of Materials ..........................................................................................................9
Transformer Specification.........................................................................................10
7.1
Electrical Diagram .............................................................................................10
Electrical Specifications.....................................................................................10
Materials............................................................................................................10
Transformer Build Diagram ...............................................................................11
Transformer Construction..................................................................................11
7.2
7.3
7.4
7.5
8
9
Transformer Spreadsheet.........................................................................................12
Performance Data ....................................................................................................14
9.1
Efficiency at Full Load (400mA) ........................................................................14
Efficiency vs. Output Current.............................................................................15
Efficiency and Input Power Comparison to Transformer + LDO........................16
No-load Input Power..........................................................................................17
Regulation.........................................................................................................18
9.2
9.3
9.4
9.5
9.5.1
9.5.2
Load and Line ............................................................................................18
Battery Load Charge Profile at 120VAC Input............................................18
10
Waveforms............................................................................................................19
10.1 Drain Voltage and Current, Normal Operation ..................................................19
10.2 Output Voltage Start-up Profile .........................................................................19
10.3 Output Ripple Measurements............................................................................20
10.3.1 Ripple Measurement Technique ................................................................20
10.3.2 Measurement Results ................................................................................21
11
12
Conducted EMI.....................................................................................................22
Revision History....................................................................................................23
Important Note:
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.
Power Integrations
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