SNVSB35B
May 2018 – June 2020
LM26420-Q1
PRODUCTION DATA.
1
Features
2
Applications
3
Description
Device Images
LM26420 Dual Buck DC/DC Converter
LM26420 Efficiency (Up to 93%)
4
Revision History
5
Pin Configuration and Functions
Pin Functions: 16-Pin WQFN
Pin Functions 20-Pin HTSSOP
6
Specifications
6.1
Absolute Maximum Ratings
6.2
ESD Ratings
6.3
Recommended Operating Conditions
6.4
Thermal Information
6.5
Electrical Characteristics Per Buck
6.6
Typical Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Soft Start
7.3.2
Power Good
7.3.3
Precision Enable
7.4
Device Functional Modes
7.4.1
Output Overvoltage Protection
7.4.2
Undervoltage Lockout
7.4.3
Current Limit
7.4.4
Thermal Shutdown
8
Application and Implementation
8.1
Application Information
8.1.1
Programming Output Voltage
8.1.2
VINC Filtering Components
8.1.3
Using Precision Enable and Power Good
8.1.4
Overcurrent Protection
8.2
Typical Applications
8.2.1
2.2-MHz, 0.8-V Typical High-Efficiency Application Circuit
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
Inductor Selection
8.2.1.2.3
Input Capacitor Selection
8.2.1.2.4
Output Capacitor
8.2.1.2.5
Calculating Efficiency and Junction Temperature
8.2.1.3
Application Curves
8.2.2
2.2-MHz, 1.8-V Typical High-Efficiency Application Circuit
8.2.2.1
Design Requirements
8.2.2.2
Detailed Design Procedure
8.2.2.3
Application Curves
8.2.3
LM26420-Q12.2-MHz, 2.5-V Typical High-Efficiency Application Circuit
8.2.3.1
Design Requirements
8.2.3.2
Detailed Design Procedure
8.2.3.3
Application Curves
9
Power Supply Recommendations
10
Layout
10.1
Layout Guidelines
10.2
Layout Example
10.3
Thermal Considerations
10.3.1
Method 1: Silicon Junction Temperature Determination
10.3.2
Thermal Shutdown Temperature Determination
11
Device and Documentation Support
11.1
Device Support
11.1.1
Third-Party Products Disclaimer
11.1.2
Custom Design With WEBENCH® Tools
11.2
Documentation Support
11.2.1
Related Documentation
11.3
Receiving Notification of Documentation Updates
11.4
Support Resources
11.5
Trademarks
11.6
Electrostatic Discharge Caution
11.7
Glossary
12
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
PWP|20
MHTS001G
RUM|16
MPQF223A
Thermal pad, mechanical data (Package|Pins)
PWP|20
PPTD289
RUM|16
QFND453A
Orderable Information
snvsb35b_oa
snvsb35b_pm
8.2.3.3
Application Curves
See
Application Curves
above.