SNOSB22D
October 2008 – April 2025
LM5574-Q1
PRODUCTION DATA
1
1
Features
2
Applications
3
Description
4
Pin Configuration and Functions
5
Specifications
5.1
Absolute Maximum Ratings
5.2
ESD Ratings
5.3
Recommended Operating Conditions
5.4
Thermal Information
5.5
Electrical Characteristics
5.6
Typical Characteristics
6
Detailed Description
6.1
Overview
6.2
Functional Block Diagram
6.3
Feature Description
6.3.1
Shutdown and Standby
6.3.2
Current Limit
6.3.3
Soft Start
6.3.4
Thermal Protection
6.4
Device Functional Modes
6.4.1
High Voltage Start-Up Regulator
6.4.2
Oscillator and Sync Capability
6.4.3
Error Amplifier and PWM Comparator
6.4.4
Ramp Generator
6.4.5
Maximum Duty Cycle and Input Dropout Voltage
6.4.6
Boost Pin
7
Application and Implementation
7.1
Application Information
7.1.1
Bias Power Dissipation Reduction
7.2
Typical Application
7.2.1
Design Requirements
7.2.2
Detailed Design Procedure
7.2.2.1
Custom Design With WEBENCH® Tools
7.2.2.2
External Components
7.2.2.3
R3 (RT)
7.2.2.4
L1- Inductor
7.2.2.5
C3- Ramp Capacitor
7.2.2.6
C9 -Output Capacitor
7.2.2.7
D1 - Async Diode
7.2.2.8
C1- Input Capacitor
7.2.2.9
C8 - Vcc Capacitor
7.2.2.10
C7 - BST Capacitor
7.2.2.11
C4 - SS Capacitor
7.2.2.12
R5, R6 - Feedback Resistor
7.2.2.13
R1, R2, C2 - SD Pin Components
7.2.2.14
R4, C5, C6 - Compensation Components
7.2.3
Application Curves
7.3
Power Supply Recommendations
7.4
Layout
7.4.1
Layout Guidelines
7.4.2
Layout Example
7.4.3
Power Dissipation
7.4.4
Thermal Considerations
8
Device and Documentation Support
8.1
Device Support
8.1.1
Development Support
8.1.1.1
Custom Design With WEBENCH® Tools
8.2
Receiving Notification of Documentation Updates
8.3
Support Resources
8.4
Trademarks
8.5
Electrostatic Discharge Caution
8.6
Glossary
9
Revision History
10
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
PW|16
MPDS361B
Thermal pad, mechanical data (Package|Pins)
Orderable Information
snosb22d_oa
snosb22d_pm
Data Sheet
LM5574-Q1 75V, 0.5A, Automotive, Step-Down Switching Regulator