application brief AB20 3
replaces AN
1149
3
Electrical Design
Considerations for
SuperFlux LEDs
Table of Contents
Overview
Summary
Electrical Design Process Overview
Circuit Design Overview
Worst Case Circuit Analysis and Validation
Comparison of Different Methods of Worst Case Circuit Analysis
Characterization of Prototype LED Signal Lamp
Validation of LED Signal Lamp
Key Concepts for Electrical Design of LED Signal Lamps
Resistor Limited Drive Circuits
Effect of LED String Length on Forward Current Regulation
Forward Current Variations between LED Emitters in an Array
EMC Transient Protection Circuits
Stop/Tail Drive Circuits
2
3
4
5
5
7
7
8
8
9
10
12
12
13
16
17
18
19
21
24
27
29
29
30
31
32
Theory
Electrical, Optical, and Thermal Characteristics of LED Emitters
LED Emitter Modeling
Linear Forward Voltage Model
Luminous Flux Models Versus Forward Current and Temperature
Thermal Resistance Models
Applications
Resistive Current Limiting
CHMSL Design Example
EMC Transient Protection
Special Considerations for Dual Luminous Intensity Operation
Luminous Flux Variations at Low Currents
PWM Drive Circuit for Tail Functions
Current and Voltage Regulator Circuits
Operation of Shunt, Series Pass, and Switching Regulators
LUMILEDS [ LUMILEDS LIGHTING COMPANY ]
