SLUSEP7
December 2022
LMR51440
,
LMR51450
PRODUCTION DATA
1
Features
2
Applications
3
Description
4
Revision History
5
Device Comparison Table
6
Pin Configuration and Functions
7
Specifications
7.1
Absolute Maximum Ratings
ESD Ratings
7.2
Recommended Operating Conditions
7.3
Thermal Information
7.4
Electrical Characteristics
7.5
System Characteristics
7.6
Typical Characteristics
8
Detailed Description
8.1
Overview
8.2
Functional Block Diagram
8.3
Feature Description
8.3.1
Fixed Frequency Peak Current Mode Control
8.3.2
Adjustable Output Voltage
8.3.3
Enable
8.3.4
Switching Frequency
8.3.5
Power-Good Flag Output
8.3.6
Minimum ON-Time, Minimum OFF-Time, and Frequency Foldback
8.3.7
Bootstrap Voltage
8.3.8
Overcurrent and Short-Circuit Protection
8.3.9
Soft Start
8.3.10
Thermal Shutdown
8.4
Device Functional Modes
8.4.1
Shutdown Mode
8.4.2
Active Mode
8.4.3
CCM Mode
8.4.4
Light-Load Operation (PFM Version)
8.4.5
Light-Load Operation (FPWM Version)
9
Application and Implementation
9.1
Application Information
9.2
Typical Application
9.2.1
Design Requirements
9.2.2
Detailed Design Procedure
9.2.2.1
Output Voltage Set-Point
9.2.2.2
Switching Frequency
9.2.2.3
Inductor Selection
9.2.2.4
Output Capacitor Selection
9.2.2.5
Input Capacitor Selection
9.2.2.6
Bootstrap Capacitor
9.2.2.7
Undervoltage Lockout Set-Point
9.2.3
Application Curves
9.3
Best Design Practices
9.4
Power Supply Recommendations
9.5
Layout
9.5.1
Layout Guidelines
9.5.1.1
Compact Layout for EMI Reduction
9.5.1.2
Feedback Resistors
9.5.2
Layout Example
10
Device and Documentation Support
10.1
Device Support
10.1.1
Development Support
10.1.1.1
Custom Design With WEBENCH® Tools
10.2
Documentation Support
10.2.1
Related Documentation
10.3
Receiving Notification of Documentation Updates
10.4
Support Resources
10.5
Trademarks
10.6
Electrostatic Discharge Caution
10.7
Glossary
11
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
DRR|12
MPSS085A
Thermal pad, mechanical data (Package|Pins)
DRR|12
PPTD377
Orderable Information
slusep7_oa
slusep7_pm
5
Device Comparison Table
ORDERABLE PART NUMBER
Current
PFM OR FPWM
Spread Specturm
LMR51440SDRRR
4 A
PFM
Yes
LMR51450SDRRR
5 A
PFM
Yes
LMR51450FNDRRR
5 A
FPWM
No