SNVS615K
January 2010 – February 2018
LM27402
PRODUCTION DATA.
1
Features
2
Applications
3
Description
Device Images
Typical Application Circuit
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
Timing Requirements
6.7
Switching Characteristics
6.8
Typical Performance Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Wide Input Voltage Range
7.3.2
UVLO
7.3.3
Precision Enable
7.3.4
Soft-Start and Voltage Tracking
7.3.5
Output Voltage Setpoint and Accuracy
7.3.6
Voltage-Mode Control
7.3.7
Power Good
7.3.8
Inductor-DCR-Based Overcurrent Protection
7.3.9
Current Sensing
7.3.10
Power MOSFET Gate Drivers
7.3.11
Pre-Bias Start-up
7.4
Device Functional Modes
7.4.1
Fault Conditions
7.4.1.1
Thermal Protection
7.4.1.2
Current Limit
7.4.1.3
Negative Current Limit
7.4.1.4
Undervoltage Threshold (UVT)
7.4.1.5
Overvoltage Threshold (OVT)
8
Application and Implementation
8.1
Application Information
8.1.1
Converter Design
8.1.2
Inductor Selection (L)
8.1.3
Output Capacitor Selection (COUT)
8.1.4
Input Capacitor Selection (CIN)
8.1.5
Using Precision Enable
8.1.6
Setting the Soft-Start Time
8.1.7
Tracking
8.1.8
Setting the Switching Frequency
8.1.9
Setting the Current Limit Threshold
8.1.10
Control Loop Compensation
8.1.11
MOSFET Gate Drivers
8.1.12
Power Loss and Efficiency Calculations
8.1.12.1
Power MOSFETs
8.1.12.2
High-Side Power MOSFET
8.1.12.3
Low-Side Power MOSFET
8.1.12.4
Gate-Charge Loss
8.1.12.5
Input and Output Capacitor ESR Losses
8.1.12.6
Inductor Losses
8.1.12.7
Controller Losses
8.1.12.8
Overall Efficiency
8.2
Typical Applications
8.2.1
Example Circuit 1
8.2.1.1
Design Requirements
8.2.1.2
Detailed Design Procedure
8.2.1.2.1
Custom Design With WEBENCH® Tools
8.2.1.3
Application Curves
8.2.2
Example Circuit 2
8.2.3
Example Circuit 3
9
Power Supply Recommendations
10
Layout
10.1
Layout Guidelines
10.1.1
Power Stage Layout
10.1.2
Gate Drive Layout
10.1.3
Controller Layout
10.1.4
Thermal Design and Layout
10.2
Layout Example
11
Device and Documentation Support
11.1
Device Support
11.1.1
Third-Party Products Disclaimer
11.1.2
Development Support
11.1.2.1
Custom Design With WEBENCH® Tools
11.2
Documentation Support
11.2.1
Related Documentation
11.3
Receiving Notification of Documentation Updates
11.4
Community Resources
11.5
Trademarks
11.6
Electrostatic Discharge Caution
11.7
Glossary
12
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
RUM|16
MPQF223A
PWP|16
MPDS371A
Thermal pad, mechanical data (Package|Pins)
RUM|16
QFND453A
PWP|16
PPTD288A
Orderable Information
snvs615k_oa
snvs615k_pm
7.4
Device Functional Modes