SLVS946E
September 2009 – April 2018
TPS54418
PRODUCTION DATA.
1
Features
2
Applications
3
Description
Device Images
Simplified Schematic
Efficiency vs Output Current
4
Revision History
5
Pin Configuration and Functions
Pin 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
Fixed Frequency PWM Control
7.3.2
Slope Compensation and Output Current
7.3.3
Bootstrap Voltage (Boot) and Low Dropout Operation
7.3.4
Error Amplifier
7.3.5
Voltage Reference
7.3.6
Adjusting the Output Voltage
7.3.7
Enable and Adjusting Undervoltage Lockout
7.3.8
Soft-Start Pin
7.3.9
Sequencing
7.3.10
Constant Switching Frequency and Timing Resistor (RT/CLK Pin)
7.3.11
Overcurrent Protection
7.3.12
Frequency Shift
7.3.13
Reverse Overcurrent Protection
7.3.14
Synchronize Using the RT/CLK Pin
7.3.15
Power Good (PWRGD Pin)
7.3.16
Overvoltage Transient Protection
7.3.17
Thermal Shutdown
7.4
Device Functional Modes
7.4.1
Small Signal Model for Loop Response
7.4.2
Simple Small Signal Model for Peak Current Mode Control
7.4.3
Small Signal Model for Frequency Compensation
8
Application and Implementation
8.1
Application Information
8.2
Typical Application
8.2.1
Design Requirements
8.2.2
Detailed Design Procedure
8.2.2.1
Step One: Select the Switching Frequency
8.2.2.2
Step Two: Select the Output Inductor
8.2.2.3
Step Three: Choose the Output Capacitor
8.2.2.4
Step Four: Select the Input Capacitor
8.2.2.5
Step Five: Minimum Load DC COMP Voltage
8.2.2.6
Step Six: Choose the Soft-Start Capacitor
8.2.2.7
Step Seven: Select the Bootstrap Capacitor
8.2.2.8
Step Eight: Undervoltage Lockout Threshold
8.2.2.9
Step Nine: Select Output Voltage and Feedback Resistors
8.2.2.9.1
Output Voltage Limitations
8.2.2.10
Step 10: Select Loop Compensation Components
8.2.2.11
Power Dissipation Estimate
8.2.3
Application Curves
9
Power Supply Recommendations
10
Layout
10.1
Layout Guidelines
10.2
Layout Example
11
Device and Documentation Support
11.1
Device Support
11.1.1
Custom Design With WEBENCH® Tools
11.1.2
Development Support
11.2
Trademarks
11.3
Electrostatic Discharge Caution
11.4
Glossary
12
Mechanical, Packaging, and Orderable Information
10
Layout