SNVSCT0
July 2025
LMR71915
ADVANCE INFORMATION
1
1
Features
2
Applications
3
Description
4
Device Comparison Table
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
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Control Architecture
7.3.2
Internal VCC Regulator and Bootstrap Capacitor
7.3.3
Internal Soft Start
7.3.4
On-Time Generator
7.3.5
Current Limit
7.3.6
N-Channel Buck Switch and Driver
7.3.7
Synchronous Rectifier
7.3.8
Enable, Undervoltage Lockout (EN/UVLO)
7.3.9
Power Good (PGOOD)
7.3.10
Thermal Protection
7.4
Device Functional Modes
7.4.1
Shutdown Mode
7.4.2
Active Mode
7.4.3
Sleep Mode
8
Application and Implementation
8.1
Application Information
8.2
Typical Fly-Buck™ Converter Application
8.2.1
Design Requirements
8.2.2
Detailed Design Procedure
8.2.2.1
Switching Frequency (RT)
8.2.2.2
Transformer Selection
8.2.2.3
Secondary Output Diode
8.2.2.4
CBST Selection
8.2.2.5
Minimum Secondary Output Load
8.3
Power Supply Recommendations
8.4
Layout
8.4.1
Layout Guidelines
8.4.1.1
Compact PCB Layout for EMI Reduction
8.4.1.2
Feedback Resistors
8.4.2
Layout Example
9
Device and Documentation Support
9.1
Device Support
9.1.1
Third-Party Products Disclaimer
9.2
Documentation Support
9.2.1
Related Documentation
9.3
Receiving Notification of Documentation Updates
9.4
Support Resources
9.5
Trademarks
9.6
Electrostatic Discharge Caution
9.7
Glossary
10
Revision History
11
Mechanical, Packaging, and Orderable Information
11.1
Tape and Reel Information
1
Features
Designed for reliability in rugged applications
Wide input voltage range of 6V to 115V
Junction temperature range: –40°C to +150°C
Fixed 3ms internal soft-start timer
Peak and valley current-limit protection
Input UVLO and thermal shutdown protection
Designed for scalable industrial power supplies and battery packs
Low minimum on time of 30ns and minimum off time of 50ns
Adjustable switching frequency up to 1MHz
Diode emulation for high light-load efficiency
Auto mode with low quiescent current (5µA typical)
FPWM for Fly-Buck converter capability
1µA shutdown quiescent current
Pin-to-pin compatible with
LM5169, LM5168
,
LM5164
,
LM5163
, and
LM5013
Similar pinout and functionality to
LM5017
and
LM34927
Integration reduces design size and cost
COT mode control architecture
Integrated 0.7Ω NFET buck switch
Integrated 0.35Ω NFET synchronous rectifier
1V internal voltage reference
No loop compensation components
Internal V
CC
bias regulator and boot diode
Open-drain power-good indicator
SOIC
PowerPAD™
-8 integrated circuit package