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
1
Features
LM5574-Q1 is an automotive grade product that is AEC-Q100 grade qualified
–40°C to + 150°C operating junction temperature
Integrated 75V, 750mΩ N-Channel MOSFET
Ultra-wide input voltage range from 6V to 75V
Adjustable output voltage as low as 1.225V
1.5% feedback reference accuracy
Operating frequency adjustable between 50kHz and 500kHz with single resistor
Controller or peripheral frequency synchronization
Adjustable soft start
Emulated current mode control architecture
Wide bandwidth error amplifier
Built-in protection
Package:
TSSOP-16
Create a custom design using the LM5574-Q1 with the
WEBENCH®
Power Designer