SNVS788H
January 2012 – August 2021
LM5019
PRODUCTION DATA
1
Features
2
Applications
3
Description
4
Revision History
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
6.6
Switching Characteristics
6.7
Typical Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Control Overview
7.3.2
VCC Regulator
7.3.3
Regulation Comparator
7.3.4
Overvoltage Comparator
7.3.5
On-Time Generator
7.3.6
Current Limit
7.3.7
N-Channel Buck Switch and Driver
7.3.8
Synchronous Rectifier
7.3.9
Undervoltage Detector
7.3.10
Thermal Protection
7.3.11
Ripple Configuration
7.3.12
Soft Start
7.4
Device Functional Modes
8
Application and Implementation
8.1
Application Information
8.2
Typical Applications
8.2.1
Application Circuit: 12.5 V to 95 V Input and 10 V, 100-mA Output Buck Converter
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
RFB1, RFB2
8.2.1.2.3
Frequency Selection
8.2.1.2.4
Inductor Selection
8.2.1.2.5
Output Capacitor
8.2.1.2.6
Type II Ripple Circuit
8.2.1.2.7
VCC and Bootstrap Capacitor
8.2.1.2.8
Input Capacitor
8.2.1.2.9
UVLO
8.2.1.3
Application Curves
8.2.2
Application Circuit: 20 V to 95 V Input and 10 V, 100 mA Output Isolated Fly-Buck Converter
8.2.2.1
Design Requirements
8.2.2.2
Detailed Design Procedure
8.2.2.2.1
Transformer Turns Ratio
8.2.2.2.2
Total IOUT
8.2.2.2.3
RFB1, RFB2
8.2.2.2.4
Frequency Selection
8.2.2.2.5
Transformer Selection
8.2.2.2.6
Primary Output Capacitor
8.2.2.2.7
Secondary Output Capacitor
8.2.2.2.8
Type III Feedback Ripple Circuit
8.2.2.2.9
Secondary Diode
8.2.2.2.10
VCC and Bootstrap Capacitor
8.2.2.2.11
Input Capacitor
8.2.2.2.12
UVLO Resistors
8.2.2.2.13
VCC Diode
8.2.2.3
Application Curves
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
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
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)
DDA|8
MPDS092F
NGU|8
MPDS407A
Thermal pad, mechanical data (Package|Pins)
Orderable Information
snvs788h_oa
snvs788h_pm
2
Applications
Smart power meters
Telecommunication systems
Automotive electronics
Isolated bias supply (
Fly-Buck™
)