SNVS787I
January 2012 – August 2021
LM5018
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
Timing Requirements
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- to 95-V Input and 10-V, 300-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 Resistors
8.2.1.3
Application Curves
8.2.2
Typical Isolated DC-DC Converter Using LM5018
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
Development Support
11.1.1.1
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
snvs787i_oa
snvs787i_pm
1
Features
Wide 7.5- to 100-V input range
Integrated 300-mA high-side and
low-side switches
No schottky required
Constant on-time control
No loop compensation required
Ultra-fast transient response
Nearly constant operating frequency
Intelligent peak current limit
Adjustable output voltage from 1.225 V
Precision 2% feedback reference
Frequency adjustable to 1 MHz
Adjustable undervoltage lockout
Remote shutdown
Thermal shutdown
Packages:
WSON-8
SO
PowerPAD™
-8
Create a custom design using the LM5018 with the
WEBENCH®
power designer