TIDUCL3
February
2017
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1 Overview
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2 Resources
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3 Features
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4 Applications
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5 Design Images
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6 System Overview
- 6.1
System Description
- 6.2
Key System Specifications
- 6.3
Block Diagram
- 6.4
Highlighted Products
- 6.4.1
LMT87-Q1
- 6.4.2
TLC555-Q1
- 6.4.3
OPA2377-Q1
- 6.4.4
TL431-Q1
- 6.4.5
TPS92691-Q1
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7 System Design Theory
- 7.1
PCB and Form Factor
- 7.2
Optimizing Board Performance Based on LED String Voltage and Current
- 7.3
Switching Frequency
- 7.4
Output Overvoltage Protection (OVP)
- 7.5
Current Monitoring (IMON)
- 7.6
Thermal Foldback
- 7.6.1
Changing Thermal Foldback Response
- 7.6.1.1
Changing Starting Point for Thermal Foldback
- 7.6.1.2
Changing Slope of Thermal Foldback
- 7.6.1.3
Constant Current at High Temperatures
- 7.6.2
Thermal Foldback Without PWM Dimming
- 7.7
Clock Generation (PWM)
- 7.8
Onboard Supply and Setting Duty Cycle
- 7.9
Buffering, Averaging, and Filtering
- 7.10
Boost Converter
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8 Getting Started Hardware
- 8.1
Hardware
- 8.2
LED Selection
- 8.3
J3, LED+, LED– (Boost)
- 8.4
J1, POS(+), NEG(–)
- 8.5
J4, Temperature Sensor Connection
- 8.6
Duty Cycle Adjust
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9 Testing and Results
- 9.1
Duty Cycle Accuracy
- 9.2
Thermal Foldback Testing
- 9.3
EMI Testing
- 9.4
Accuracy Calculation
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10Design Files
- 10.1
Schematics
- 10.2
Bill of Materials
- 10.3
PCB Layout Recommendations
- 10.3.1
Layout Prints
- 10.4
Altium Project
- 10.5
Gerber Files
- 10.6
Assembly Drawings
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11Related Documentation
- 11.1
Trademarks
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12About the Author
11 Related Documentation
- Texas Instruments, TLC555-Q1 LINCMOS™ TIMER, TLC555-Q1 Datasheet (SLFS078)
- Texas Instruments, TPS92691/-Q1 Multi-Topology LED Driver With Rail-to-Rail Current Sense Amplifier, TPS92691-Q1 Datasheet (SLVSD68)
- Texas Instruments, OPAx377-Q1 Low-Noise, Low Quiescent Current, Precision Automotive Grade Operational Amplifier, OPA2377-Q1 Datasheet (SBOS797)
- Texas Instruments, TL431-Q1 ADJUSTABLE PRECISION SHUNT REGULATOR, TL431A-Q1 Datasheet (SGLS302)
- Texas Instruments, TPS92691 Boost and Boost-to-Battery LED Driver Evaluation Board, TPS92691-Q1 User's Guide (SLVUAO7)
- OSRAM Opto Semiconductor, SYNIOS P2720 KW DMLN31.SG Verison 1.2, SYNIOS P2720 Datasheet (http://www.osram-os.com/Graphics/XPic0/00192945_0.pdf/KW%20DMLN31.SG.pdf)