SNVSA45B
June 2014 – March 2018
LM46000
PRODUCTION DATA.
1
Features
2
Applications
3
Description
Device Images
Simplified Schematic
Radiated Emission Graph VOUT = 3.3 V, VIN = 24 V, FS= 500 kHz, IOUT = 0.5 A
4
Revision History
5
Pin Configuration and Functions
Pin 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
Timing Requirements
6.7
Switching Characteristics
6.8
Typical Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Fixed-Frequency, Peak-Current-Mode Controlled Step-Down Regulator
7.3.2
Light Load Operation
7.3.3
Adjustable Output Voltage
7.3.4
Enable (EN)
7.3.5
VCC, UVLO, and BIAS
7.3.6
Soft Start and Voltage Tracking (SS/TRK)
7.3.7
Switching Frequency (RT) and Synchronization (SYNC)
7.3.8
Minimum ON-Time, Minimum OFF-Time and Frequency Foldback at Dropout Conditions
7.3.9
Internal Compensation and CFF
7.3.10
Bootstrap Voltage (CBOOT)
7.3.11
Power Good (PGOOD)
7.3.12
Overcurrent and Short-Circuit Protection
7.3.13
Thermal Shutdown
7.4
Device Functional Modes
7.4.1
Shutdown Mode
7.4.2
Standby Mode
7.4.3
Active Mode
7.4.4
CCM Mode
7.4.5
Light Load Operation
7.4.6
Self-Bias Mode
8
Applications and Implementation
8.1
Application Information
8.2
Typical Applications
8.2.1
Design Requirements
8.2.2
Detailed Design Procedure
8.2.2.1
Custom Design With WEBENCH® Tools
8.2.2.2
Output Voltage Setpoint
8.2.2.3
Switching Frequency
8.2.2.4
Input Capacitors
8.2.2.5
Inductor Selection
8.2.2.6
Output Capacitor Selection
8.2.2.7
Feed-Forward Capacitor
8.2.2.8
Bootstrap Capacitors
8.2.2.9
VCC Capacitor
8.2.2.10
BIAS Capacitors
8.2.2.11
Soft-Start Capacitors
8.2.2.12
Undervoltage Lockout Setpoint
8.2.2.13
PGOOD
8.2.3
Application Performance Curves
9
Power Supply Recommendations
10
Layout
10.1
Layout Guidelines
10.1.1
Compact Layout for EMI Reduction
10.1.2
Ground Plane and Thermal Considerations
10.1.3
Feedback Resistors
10.2
Layout Example
11
Device and Documentation Support
11.1
Device Support
11.1.1
Custom Design With WEBENCH® Tools
11.2
Receiving Notification of Documentation Updates
11.3
Community Resources
11.4
Trademarks
11.5
Electrostatic Discharge Caution
11.6
Glossary
12
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
PWP|16
MPDS371A
Thermal pad, mechanical data (Package|Pins)
PWP|16
PPTD297B
Orderable Information
snvsa45b_oa
snvsa45b_pm
7.4
Device Functional Modes