SNVSBX7A
September 2023 – June 2024
LM70840-Q1
,
LM70860-Q1
,
LM70880-Q1
PRODUCTION DATA
1
1
Features
2
Applications
3
Description
4
Description (continued)
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
Typical Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Input Voltage Range (VIN)
7.3.2
High-Voltage Bias Supply Regulator (VCC, BIAS, VDDA)
7.3.3
Enable (EN)
7.3.4
Power-Good Monitor (PG)
7.3.5
Switching Frequency (RT)
7.3.6
Dual Random Spread Spectrum (DRSS)
7.3.7
Soft Start
7.3.8
Output Voltage Setpoint (FB)
7.3.9
Minimum Controllable On-Time
7.3.10
Error Amplifier and PWM Comparator (FB, EXTCOMP)
7.3.11
Slope Compensation
7.3.12
Shunt Current Sensing
7.3.13
Hiccup Mode Current Limiting
7.3.14
Device Configuration (CONFIG)
7.3.15
Single-Output Dual-phase Operation
7.3.16
Pulse Frequency Modulation (PFM) / Synchronization
7.3.17
Thermal Shutdown (TSD)
7.4
Device Functional Modes
7.4.1
Shutdown Mode
7.4.2
Standby Mode
7.4.3
Active Mode
7.4.4
Sleep Mode
8
Application and Implementation
8.1
Application Information
8.1.1
Power Train Components
8.1.1.1
Buck Inductor
8.1.1.2
Output Capacitors
8.1.1.3
Input Capacitors
8.1.1.4
EMI Filter
8.1.2
Error Amplifier and Compensation
8.1.3
Maximum Ambient Temperature
8.1.3.1
Derating Curves
8.2
Typical Applications
8.2.1
Design 1 – High Efficiency, Wide Input, 400-kHz Synchronous Buck Regulator
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
Custom Design With Excel Quickstart Tool
8.2.1.2.3
Buck Inductor
8.2.1.2.4
Current-Sense Resistance
8.2.1.2.5
Output Capacitors
8.2.1.2.6
Input Capacitors
8.2.1.2.7
Frequency Set Resistor
8.2.1.2.8
Feedback Resistors
8.2.1.2.9
Compensation Components
8.2.1.3
Application Curves
8.2.2
Design 2 – High Efficiency 48V to 12V 400kHz Synchronous Buck Regulator
8.2.2.1
Design Requirements
8.2.2.2
Detailed Design Procedure
8.2.2.3
Application Curves
8.3
Power Supply Recommendations
8.4
Layout
8.4.1
Layout Guidelines
8.4.2
Thermal Design and Layout
8.4.3
Layout Example
9
Device and Documentation Support
9.1
Device Support
9.1.1
Development Support
9.1.1.1
Custom Design With WEBENCH® Tools
9.2
Documentation Support
9.2.1
Related Documentation
9.2.1.1
PCB Layout Resources
9.2.1.2
Thermal Design Resources
9.3
Receiving Notification of Documentation Updates
9.4
Support Resources
9.5
Trademarks
9.6
Electrostatic Discharge Caution
9.7
Glossary
10
Revision History
11
Mechanical, Packaging, and Orderable Information
11.1
Tape and Reel Information
Package Options
Mechanical Data (Package|Pins)
RRX|29
MPQF604D
Thermal pad, mechanical data (Package|Pins)
Orderable Information
snvsbx7a_oa
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 designs requiring functional safety
Synchronous DC/DC converter with a versatile buck controller and robust power MOSFETs
Wide input voltage range: 4.5V to
80V
Shutdown mode current: 2.3µA
No-load I
Q
regulating 48V to 5V: 8.2µA
1% accurate, fixed 3.3V, 5V, 12V, or adjustable outputs from 0.8V to
55V
Dual-phase operation enabling output currents up to 16A
Optimized for low EMI requirements
Facilitates
CISPR 25 Class 5
compliance
Pin-selectable ±8% dual-random spread spectrum reduces peak emissions
Switching frequency: 200kHz to 2.2MHz
Pin-configurable AUTO or FPWM operation
Inherent protection features for robust design
Internal hiccup-mode overcurrent protection
Enable, power good, and thermal shutdown
Internal or external loop compensation
6mm × 6mm thermally optimized, RoHS compliant, QFN-29 package with Pb-free plating
Create a custom design using the
LM708x0-Q1
with
WEBENCH®
Power Designer