SNVSB32B
August 2018 – June 2021
LM5146-Q1
PRODUCTION DATA
1
Features
2
Applications
3
Description
4
Revision History
5
Description (continued)
6
Pin Configuration and Functions
6.1
Wettable Flanks
7
Specifications
7.1
Absolute Maximum Ratings
7.2
ESD Ratings
7.3
Recommended Operating Conditions
7.4
Thermal Information
7.5
Electrical Characteristics
7.6
Switching Characteristics
7.7
Typical Characteristics
8
Detailed Description
8.1
Overview
8.2
Functional Block Diagram
8.3
Feature Description
8.3.1
Input Range (VIN)
8.3.2
Output Voltage Setpoint and Accuracy (FB)
8.3.3
High-Voltage Bias Supply Regulator (VCC)
8.3.4
Precision Enable (EN/UVLO)
8.3.5
Power Good Monitor (PGOOD)
8.3.6
Switching Frequency (RT, SYNCIN)
8.3.6.1
Frequency Adjust
8.3.6.2
Clock Synchronization
8.3.7
Configurable Soft Start (SS/TRK)
8.3.7.1
Tracking
8.3.8
Voltage-Mode Control (COMP)
8.3.9
Gate Drivers (LO, HO)
8.3.10
Current Sensing and Overcurrent Protection (ILIM)
8.3.11
OCP Duty Cycle Limiter
8.4
Device Functional Modes
8.4.1
Shutdown Mode
8.4.2
Standby Mode
8.4.3
Active Mode
8.4.4
Diode Emulation Mode
8.4.5
Thermal Shutdown
9
Application and Implementation
9.1
Application Information
9.1.1
Design and Implementation
9.1.2
Power Train Components
9.1.2.1
Inductor
9.1.2.2
Output Capacitors
9.1.2.3
Input Capacitors
9.1.2.4
Power MOSFETs
9.1.3
Control Loop Compensation
9.1.4
EMI Filter Design
9.2
Typical Applications
9.2.1
Design 1 – 12-A High-Efficiency Synchronous Buck DC/DC Regulator for Automotive Applications
9.2.1.1
Design Requirements
9.2.1.2
Detailed Design Procedure
9.2.1.3
Custom Design With WEBENCH® Tools
9.2.1.4
Custom Design With Excel Quickstart Tool
9.2.1.5
Application Curves
9.2.2
Design 2 – High Density, 12-V, 8-A Rail From 48-V Automotive Battery Power
9.2.2.1
Design Requirements
9.2.2.2
Detailed Design Procedure
9.2.2.3
Application Curves
10
Power Supply Recommendations
11
Layout
11.1
Layout Guidelines
11.1.1
Power Stage Layout
11.1.2
Gate Drive Layout
11.1.3
PWM Controller Layout
11.1.4
Thermal Design and Layout
11.1.5
Ground Plane Design
11.2
Layout Example
12
Device and Documentation Support
12.1
Device Support
12.1.1
Third-Party Products Disclaimer
12.1.2
Development Support
12.1.2.1
Custom Design With WEBENCH® Tools
12.2
Documentation Support
12.2.1
Related Documentation
12.2.1.1
PCB Layout Resources
12.2.1.2
Thermal Design Resources
12.3
Receiving Notification of Documentation Updates
12.4
Support Resources
12.5
Trademarks
12.6
Electrostatic Discharge Caution
12.7
Glossary
13
Mechanical, Packaging, and Orderable Information
1
Features
AEC-Q100 qualified for automotive applications:
Device temperature grade 1: –40°C to +125°C ambient temperature range
Functional Safety-Capable
Documentation available to aid functional safety system design
Versatile synchronous buck DC/DC controller
Wide input voltage range of 5.5 V to 100 V
150°C maximum junction temperature
0.8-V reference with ±1% feedback accuracy
Adjustable output voltage from 0.8 V to 60 V
40-ns t
ON(min)
for high V
IN
/ V
OUT
ratio
140-ns t
OFF(min)
for low dropout
Lossless R
DS(on)
or shunt current sensing
Optimized for
CISPR 25 Class 5
requirements
Switching frequency from 100 kHz to 1 MHz
SYNC In and SYNC Out capability
Selectable diode emulation or FPWM
7.5-V gate drivers for standard V
TH
MOSFETs
14-ns adaptive dead-time control
2.3-A source and 3.5-A sink capability
Inherent protection features for robust design
Adjustable output voltage soft start
Hiccup-mode overcurrent protection
Input UVLO with hysteresis
VCC and gate-drive UVLO protection
Precision enable input and open-drain PGOOD indicator for sequencing and control
Thermal shutdown protection with hysteresis
20-pin VQFN package with wettable flanks
Create a custom design using the LM5146-Q1 with
WEBENCH®
Power Designer