SNVS276I
April 2004 – February 2019
LM2743
PRODUCTION DATA.
1
Features
2
Applications
3
Description
Device Images
Typical Application Diagram
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
Start Up and Soft-Start
7.3.2
Normal Operation
7.3.3
Tracking a Voltage Level
7.3.4
Tracking Voltage Slew Rate
7.3.5
Sequencing
7.3.6
SD Pin Impedance
7.3.7
MOSFET Gate Drivers
7.3.8
Power Good Signal
7.3.9
UVLO
7.3.10
Current Limit
7.3.11
Foldback Current Limit
7.4
Device Functional Modes
7.4.1
Shutdown
8
Application and Implementation
8.1
Application Information
8.2
Typical Applications
8.2.1
Synchronous Buck Converter Typical Application using LM2743
8.2.1.1
Design Requirements
8.2.1.2
Detailed Design Procedure
8.2.1.2.1
Custom Design With WEBENCH® Tools
8.2.1.2.2
Duty Cycle Calculation
8.2.1.2.3
Input Capacitor
8.2.1.2.4
Output Inductor
8.2.1.2.5
Output Capacitor
8.2.1.2.6
MOSFETs
8.2.1.2.7
Support Components
8.2.1.2.8
Control Loop Compensation
8.2.1.2.9
Efficiency Calculations
8.2.1.3
Application Curves
8.2.2
Example Circuit 1
8.2.2.1
Design Requirements
8.2.2.2
Detailed Design Procedure
8.2.2.3
Bill of Materials
8.2.3
Example Circuit 2
8.2.3.1
Design Requirements
8.2.3.2
Detailed Design Procedure
8.2.3.3
Bill of Materials
8.2.4
Example Circuit 3
8.2.4.1
Design Requirements
8.2.4.2
Detailed Design Procedure
8.2.4.3
Bill of Materials
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
Development Support
11.1.1.1
Custom Design With WEBENCH® Tools
11.2
Receiving Notification of Documentation Updates
11.3
Community Resources
11.4
Trademarks
11.5
Electrostatic Discharge Caution
11.6
Glossary
12
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
PW|14
MPDS360
Thermal pad, mechanical data (Package|Pins)
PW|14
QFND305D
Orderable Information
snvs276i_oa
snvs276i_pm
8.2.1.3
Application Curves
V
CC
= 3.3V
V
OUT
= 1.2V
I
OUT
= 4A
C
SS
= 12nF
f
SW
= 300 kHz
Figure 39.
Start-Up (Full-Load)
V
CC
= 3.3 V
V
OUT
= 1.2 V
I
OUT
= 4 A
C
SS
= 12 nF
f
SW
= 300 kHz
Figure 40.
Shutdown (Full-Load)