Contents
1 Preface ............................................................................................................................... 4
1.1 About this Manual........................................................................................................ 4
1.2 Related Documentation from Texas Instruments .................................................................... 4
1.3 FCC Warning ............................................................................................................. 4
1.4 If You Need Assistance ................................................................................................. 4
2 Introduction......................................................................................................................... 4
3 Description of the LP8861-Q1 Device...................................................................................... 5
3.1 Features................................................................................................................... 5
3.2 Applications ............................................................................................................... 5
4 Hardware Setup ................................................................................................................... 6
5 Board Layout....................................................................................................................... 7
6 Start-Up of the EVM and Power Sequences............................................................................. 8
6.1 PWM Input to Initiate Start-up Sequence............................................................................. 8
6.2 Shutdown Sequence..................................................................................................... 9
7 Boost Converter................................................................................................................. 10
7.1 Switching Frequency .................................................................................................. 10
7.2 Spread Spectrum and Synchronization.............................................................................. 10
7.3 Voltage Control.......................................................................................................... 11
8 LED Current Sinks.............................................................................................................. 12
8.1 Output Configuration ................................................................................................... 12
8.2 Current Setting.......................................................................................................... 12
8.3 Brightness Control...................................................................................................... 12
9 External Temperature Sensor Functionality .......................................................................... 13
9.1 Overview................................................................................................................. 13
9.2 Calculator................................................................................................................ 13
10 Fault Detection................................................................................................................... 13
10.1 Fault Indicator........................................................................................................... 13
11 Evaluation Board Schematic................................................................................................ 14
12 Bill of Materials .................................................................................................................. 15
13 Appendix A: LED Load Board .............................................................................................. 17
2Table of Contents SNVU456–July 2015
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