SNVSC00
February 2023
LM5148-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
Typical Characteristics
8
Detailed Description
8.1
Overview
8.2
Functional Block Diagram
8.3
Feature Description
8.3.1
Input Voltage Range (VIN)
8.3.2
High-Voltage Bias Supply Regulator (VCC, VCCX, VDDA)
8.3.3
Precision Enable (EN)
8.3.4
Power-Good Monitor (PG)
8.3.5
Switching Frequency (RT)
8.3.6
Dual Random Spread Spectrum (DRSS)
8.3.7
Soft Start
8.3.8
Output Voltage Setpoint (FB)
8.3.9
Minimum Controllable On Time
8.3.10
Error Amplifier and PWM Comparator (FB, EXTCOMP)
8.3.11
Slope Compensation
8.3.12
Inductor Current Sense (ISNS+, VOUT)
8.3.12.1
Shunt Current Sensing
8.3.12.2
Inductor DCR Current Sensing
8.3.13
Hiccup Mode Current Limiting
8.3.14
High-Side and Low-Side Gate Drivers (HO, LO)
8.3.15
Output Configurations (CNFG)
8.3.16
Single-Output Dual-Phase Operation
8.4
Device Functional Modes
8.4.1
Sleep Mode
8.4.2
Pulse Frequency Modulation and Synchronization (PFM/SYNC)
8.4.3
Thermal Shutdown
9
Application and Implementation
9.1
Application Information
9.1.1
Power Train Components
9.1.1.1
Buck Inductor
9.1.1.2
Output Capacitors
9.1.1.3
Input Capacitors
9.1.1.4
Power MOSFETs
9.1.1.5
EMI Filter
9.1.2
Error Amplifier and Compensation
9.2
Typical Applications
9.2.1
Design 1 – High Efficiency 2.1-MHz Synchronous Buck Regulator
9.2.1.1
Design Requirements
9.2.1.2
Detailed Design Procedure
9.2.1.2.1
Custom Design with WEBENCH® Tools
9.2.1.2.2
Custom Design with Excel Quickstart Tool
9.2.1.2.3
Buck Inductor
9.2.1.2.4
Current-Sense Resistance
9.2.1.2.5
Output Capacitors
9.2.1.2.6
Input Capacitors
9.2.1.2.7
Frequency Set Resistor
9.2.1.2.8
Feedback Resistors
9.2.1.2.9
Compensation Components
9.2.1.3
Application Curves
9.2.2
Design 2 – High Efficiency 48-V to 12-V 400-kHz Synchronous Buck Regulator
9.2.2.1
Design Requirements
9.2.2.2
Detailed Design Procedure
9.2.2.3
Application Curves
9.2.3
Design 3 – High Efficiency 440-kHz Synchronous Buck Regulator
9.2.3.1
Design Requirements
9.2.3.2
Detailed Design Procedure
9.2.3.3
Application Curves
9.2.4
Design 4 – Dual-Phase 400-kHz 20-A Synchronous Buck Regulator
9.2.4.1
Design Requirements
9.2.4.2
Detailed Design Procedure
9.2.4.3
Application Curves
9.3
Power Supply Recommendations
9.4
Layout
9.4.1
Layout Guidelines
9.4.1.1
Power Stage Layout
9.4.1.2
Gate-Drive Layout
9.4.1.3
PWM Controller Layout
9.4.1.4
Thermal Design and Layout
9.4.1.5
Ground Plane Design
9.4.2
Layout Example
10
Device and Documentation Support
10.1
Device Support
10.1.1
Development Support
10.1.1.1
Custom Design with WEBENCH® Tools
10.2
Documentation Support
10.2.1
Related Documentation
10.2.1.1
PCB Layout Resources
10.2.1.2
Thermal Design Resources
10.3
Receiving Notification of Documentation Updates
10.4
Support Resources
10.5
Trademarks
10.6
Electrostatic Discharge Caution
10.7
Glossary
11
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
RGY|19
MPQF777A
RGY|24
MPQF143E
Thermal pad, mechanical data (Package|Pins)
RGY|19
QFND668
RGY|24
QFND819
Orderable Information
snvsc00_oa
snvsc00_pm
1
Features
AEC-Q100 qualified for automotive applications:
Device temperature grade 1: –40°C to +125°C ambient operating temperature
Functional Safety-Capable
Documentation available to aid functional safety system design
Integrated EMI mitigation
Selectable dual random spread spectrum (DRSS) feature for
enhanced EMI performance
across low and high-frequency bands
Optimized for
CISPR 25 Class 5 requirements
Versatile synchronous buck DC/DC controller
Wide input voltage range of 3.5 V to
80 V
1% accurate, fixed 3.3 V, 5 V, 12 V, or adjustable output from 0.8 V to
55 V
150°C maximum junction temperature
Lossless DCR or shunt current sensing
Shutdown mode current of 2.3 µA
No-load sleep current of 9.5 µA
Internal soft-start ramp of 3 ms
Stackable up to two phases
Internal bootstrap diode
Switching frequency from 100 kHz to 2.2 MHz
SYNC in and SYNC out capability
Selectable PFM or FPWM modes
Inherent protection features for robust design
Internal hiccup mode overcurrent protection
ENABLE and PGOOD functions
VCC, VDDA, and gate-drive UVLO protection
Internal or external loop compensation
Thermal shutdown protection with hysteresis
Create a custom design using the
LM5148-Q1 with
WEBENCH®
Power Designer