SLVSB14B
October 2011 – February 2016
TPS54821
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
Fixed Frequency PWM Control
7.3.2
Continuous Current Mode Operation (CCM)
7.3.3
VIN and Power VIN Pins (VIN and PVIN)
7.3.4
Voltage Reference
7.3.5
Adjusting the Output Voltage
7.3.6
Safe Start-up into Pre-Biased Outputs
7.3.7
Error Amplifier
7.3.8
Slope Compensation
7.4
Device Functional Modes
7.4.1
Enable and Adjusting Undervoltage Lockout
7.4.2
Adjustable Switching Frequency and Synchronization (RT/CLK)
7.4.3
Adjustable Switching Frequency (RT Mode)
7.4.4
Synchronization (CLK mode)
7.4.5
Slow Start (SS/TR)
7.4.6
Power Good (PWRGD)
7.4.7
Bootstrap Voltage (BOOT) and Low Dropout Operation
7.4.8
Sequencing (SS/TR)
7.4.9
Output Overvoltage Protection (OVP)
7.4.10
Overcurrent Protection
7.4.11
Thermal Shutdown
7.4.12
Small Signal Model for Loop Response
7.4.13
Simple Small Signal Model for Peak Current Mode Control
7.4.14
Small Signal Model for Frequency Compensation
8
Application and Implementation
8.1
Application Information
8.2
Typical Application
8.2.1
Design Parameters
8.2.2
Design Guide - Step-By-Step Design Procedure
8.2.2.1
Typical Application Schematic
8.2.2.2
Operating Frequency
8.2.2.3
Output Inductor Selection
8.2.2.4
Output Capacitor Selection
8.2.2.5
Input Capacitor Selection
8.2.2.6
Slow Start Capacitor Selection
8.2.2.7
Bootstrap Capacitor Selection
8.2.2.8
Under Voltage Lockout Set Point
8.2.2.9
Output Voltage Feedback Resistor Selection
8.2.2.9.1
Minimum Output Voltage
8.2.2.10
Compensation Component Selection
8.2.2.11
Fast Transient Considerations
8.2.3
Application Curves
9
Power Supply Recommendations
10
Layout
10.1
PCB Layout Guidelines
10.2
Layout Example
10.2.1
Estimated Circuit Area
11
Device and Documentation Support
11.1
Trademarks
11.2
Electrostatic Discharge Caution
11.3
Glossary
12
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
RHL|14
MPQF252H
Thermal pad, mechanical data (Package|Pins)
Orderable Information
slvsb14b_oa
slvsb14b_pm