SLUSE50 November 2023 TPS92642-Q1
PRODUCTION DATA
- 1
- 1 Features
- 2 Applications
- 3 Description
- 4 Pin Configuration and Functions
- 5 Specifications
-
6 Detailed Description
- 6.1 Overview
- 6.2 Functional Block Diagram
- 6.3
Feature Description
- 6.3.1 Internal Regulator
- 6.3.2 Buck Converter Switching Operation
- 6.3.3 Bootstrap Supply
- 6.3.4 Switching Frequency and Adaptive On-Time Control
- 6.3.5 Minimum On-Time, Off-Time, and Inductor Ripple
- 6.3.6 LED Current Regulation and Error Amplifier
- 6.3.7 Start-Up Sequence
- 6.3.8 Analog Dimming and Forced Continuous Conduction Mode
- 6.3.9 External PWM Dimming and Input Undervoltage Lockout (UVLO)
- 6.3.10 Pulse Duty Cycle Limit Circuit
- 6.3.11 Output Short and Open-Circuit Faults
- 6.3.12 Overcurrent Protection
- 6.3.13 Thermal Shutdown
- 6.3.14 Fault Indicator and Diagnostics Summary
- 6.4 Device Functional Modes
-
7 Application and Implementation
- 7.1
Application Information
- 7.1.1 Duty Cycle Considerations
- 7.1.2 Switching Frequency Selection
- 7.1.3 LED Current Programming
- 7.1.4 Inductor Selection
- 7.1.5 Output Capacitor Selection
- 7.1.6 Input Capacitor Selection
- 7.1.7 Bootstrap Capacitor Selection
- 7.1.8 Compensation Capacitor Selection
- 7.1.9 Input Dropout and Undervoltage Protection
- 7.1.10 Pulse Duty Cycle Limit Circuit
- 7.1.11 Protection Diodes
- 7.2
Typical Application
- 7.2.1 Design Requirements
- 7.2.2
Detailed Design Procedure
- 7.2.2.1 Calculating Duty Cycle
- 7.2.2.2 Calculating Minimum On-Time and Off-Time
- 7.2.2.3 Minimum Switching Frequency
- 7.2.2.4 LED Current Set Point
- 7.2.2.5 Inductor Selection
- 7.2.2.6 Output Capacitor Selection
- 7.2.2.7 Bootstrap Capacitor Selection
- 7.2.2.8 Compensation Capacitor Selection
- 7.2.2.9 VIN Dropout Protection and PWM Dimming
- 7.2.3 Application Curves
- 7.3 Power Supply Recommendations
- 7.4 Layout
- 7.1
Application Information
- 8 Device and Documentation Support
- 9 Revision History
- 10Mechanical, Packaging, and Orderable Information
7.2.3 Application Curves
| Ch1: SW voltage (10 V/div); Ch2: Output voltage (1 V/div); Ch3: Inductor current (1 A/div); Ch4: VIN voltage (10 V/div); Time: 5 ms/div |
| Ch1: SW voltage (5 V/div); Ch2: Output voltage (2 V/div); Ch3: Inductor current (1 A/div); Time: 5 μs/div |
| Ch2: Output voltage (4 V/div); Ch3: LED current (1 A/div); Ch4: FLT voltage (2 V/div); Time: 40 ms/div |
| Ch1: SW voltage (5 V/div); Ch2: Output voltage (2 V/div); Ch3: LED current (1 A/div); Time: 400 ns/div |
| Ch1: SW voltage (5 V/div); Ch2: Output voltage (2 V/div); Ch3: Inductor current (1 A/div); Time: 1 μs/div |
| Ch2: Output voltage (4 V/div); Ch3: LED current (1 A/div); Ch4: FLT voltage (2 V/div); Time: 40 ms/div |