SNVSA46B
June 2014 – January 2018
LM46001
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 = 1 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 (ENABLE)
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
Stand-by 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 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
Development Support
11.1.1.1
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
snvsa46b_oa
snvsa46b_pm
1
Features
24-µA Quiescent Current in Regulation
High Efficiency at Light Load (DCM and PFM)
Meets EN55022/CISPR 22 EMI standards
Integrated Synchronous Rectification
Adjustable Switching Frequency: 200 kHz to 2.2
MHz (500 kHz default)
Frequency Synchronization to External Clock
Internal Compensation
Stable With Many Combinations of Ceramic, Polymer, Tantalum, and Aluminum Capacitors
Power-Good Flag
Soft Start into Pre-Biased Load
Internal Soft Start: 4.1 ms
Extendable Soft-Start Time by External Capacitor
Output Voltage Tracking Capability
Precision Enable to Program System UVLO
Output Short-Circuit Protection With Hiccup Mode
Overtemperature Thermal Shutdown Protection
Create a Custom Design Using the LM46001 With the
WEBENCH® Power Designer