SNVSAU3B
December 2017 – October 2019
LM76002-Q1
,
LM76003-Q1
PRODUCTION DATA.
1
Features
2
Applications
3
Description
Simplified Schematic
Efficiency vs Output Current (VOUT = 5 V, fSW = 400 kHz, Auto Mode)
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 Characteristics
6.7
Switching Characteristics
6.8
System Characteristics
6.9
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 Control
7.3.2
Light Load Operation Modes — PFM and FPWM
7.3.3
Adjustable Output Voltage
7.3.4
Enable (EN Pin) and UVLO
7.3.5
Internal LDO, VCC UVLO, and Bias Input
7.3.6
Soft Start and Voltage Tracking (SS/TRK)
7.3.7
Adjustable Switching Frequency (RT) and Frequency Synchronization
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 and VBOOT UVLO (BOOT Pin)
7.3.11
Power Good and Overvoltage Protection (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
DCM Mode
7.4.6
Light Load Mode
7.4.7
Foldback Mode
7.4.8
Forced Pulse-Width-Modulation Mode
7.4.9
Self-Bias Mode
8
Application 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 Capacitors
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
8.2.2.14
Synchronization
8.2.3
Application Curves
9
Power Supply Recommendations
10
Layout
10.1
Layout Guidelines
10.1.1
Layout Highlights
10.1.2
Compact Layout for EMI Reduction
10.1.3
Ground Plane and Thermal Considerations
10.1.4
Feedback Resistors
10.2
Layout Example
10.3
Thermal Design
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
Support Resources
11.4
Trademarks
11.5
Electrostatic Discharge Caution
11.6
Glossary
12
Mechanical, Packaging, and Orderable Information
6.9
Typical Characteristics
Unless otherwise specified, V
IN
= 24 V. Curves represent most likely parametric norm at specified condition.
Figure 1.
High-Side and Low-Side Switch R
DS-ON
Figure 3.
Feedback Voltage
Figure 5.
LM76002-Q1
High-Side and Low-Side Current Limits
Figure 7.
Switching Frequency With R
T
Open
Figure 9.
PGOOD Threshold
Figure 2.
Shutdown Quiescent Current
Figure 4.
LM76003-Q1
High-Side and Low-Side Current Limits
Figure 6.
Switching Frequency Set by R
T
Resistor
Figure 8.
Enable Threshold