SLVSD68
December 2015
TPS92691
,
TPS92691-Q1
PRODUCTION DATA.
1
Features
2
Applications
3
Description
4
Revision History
5
Pin Configuration and Functions
6
Specifications
6.1
Absolute Maximum Ratings
6.2
ESD Ratings
6.3
Recommended Operating Conditions
6.4
Thermal Information
6.5
Electrical Characteristics
6.6
Typical Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Internal Regulator and Undervoltage Lockout (UVLO)
7.3.2
Oscillator
7.3.3
Gate Driver
7.3.4
Rail-to-Rail Current Sense Amplifier
7.3.5
Transconductance Error Amplifier
7.3.6
Switch Current Sense and Internal Slope Compensation
7.3.7
Analog Adjust Input
7.3.8
PWM Input and Series Dimming FET Gate Driver Output
7.3.9
Soft-Start
7.3.10
Current Monitor Output
7.3.11
Overvoltage Protection
7.3.12
Thermal Protection
7.4
Device Functional Modes
8
Application and Implementation
8.1
Application Information
8.1.1
Duty Cycle Considerations
8.1.2
Inductor Selection
8.1.3
Output Capacitor Selection
8.1.4
Input Capacitor Selection
8.1.5
Main Power MOSFET Selection
8.1.6
Rectifier Diode Selection
8.1.7
LED Current Programming
8.1.8
Switch Current Sense Resistor and Slope Compensation
8.1.9
Feedback Compensation
8.1.10
Soft-Start
8.1.11
Overvoltage Protection
8.1.12
PWM Dimming Considerations
8.2
Typical Applications
8.2.1
Typical Boost LED Driver
8.2.1.1
Design Requirements
8.2.1.2
Detailed Design Procedure
8.2.1.2.1
Calculating Duty Cycle
8.2.1.2.2
Setting Switching Frequency
8.2.1.2.3
Inductor Selection
8.2.1.2.4
Output Capacitor Selection
8.2.1.2.5
Input Capacitor Selection
8.2.1.2.6
Main N-Channel MOSFET Selection
8.2.1.2.7
Rectifying Diode Selection
8.2.1.2.8
Programming LED Current
8.2.1.2.9
Setting Switch Current Limit and Slope Compensation
8.2.1.2.10
Deriving Compensator Parameters
8.2.1.2.11
Setting Start-up Duration
8.2.1.2.12
Setting Overvoltage Protection Threshold
8.2.1.2.13
PWM Dimming Considerations
8.2.1.3
Application Curves
8.2.2
Typical Buck-Boost LED Driver
8.2.2.1
Design Requirements
8.2.2.2
Detailed Design Procedure
8.2.2.2.1
Calculating Duty Cycle
8.2.2.2.2
Setting Switching Frequency
8.2.2.2.3
Inductor Selection
8.2.2.2.4
Output Capacitor Selection
8.2.2.2.5
Input Capacitor Selection
8.2.2.2.6
Main N-Channel MOSFET Selection
8.2.2.2.7
Rectifier Diode Selection
8.2.2.2.8
Setting Switch Current Limit and Slope Compensation
8.2.2.2.9
Programming LED Current
8.2.2.2.10
Deriving Compensator Parameters
8.2.2.2.11
Setting Startup Duration
8.2.2.2.12
Setting Overvoltage Protection Threshold
8.2.2.2.13
PWM Dimming Consideration
8.2.2.3
Application Curves
9
Power Supply Recommendations
10
Layout
10.1
Layout Guidelines
10.2
Layout Example
11
Device and Documentation Support
11.1
Related Links
11.2
Community Resources
11.3
Trademarks
11.4
Electrostatic Discharge Caution
11.5
Glossary
12
Mechanical, Packaging, and Orderable Information
4 Revision History
DATE
REVISION
NOTES
December 2015
*
Initial release.