SNVS429C
October 2006 – December 2016
LM3405
PRODUCTION DATA.
1
Features
2
Applications
3
Description
4
Revision History
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
Boost Function
7.3.2
Setting the LED Current
7.3.3
Output Voltage
7.3.4
Enable Mode or Shutdown Mode
7.3.5
LED PWM Dimming
7.3.6
Undervoltage Lockout
7.3.7
Current Limit
7.3.8
Overcurrent Protection
7.4
Device Functional Modes
7.4.1
Thermal Shutdown
8
Application and Implementation
8.1
Application Information
8.1.1
Inductor (L1)
8.1.2
Input Capacitor (C1)
8.1.3
Output Capacitor (C2)
8.1.4
Feed-Forward Capacitor (C4)
8.1.5
Catch Diode (D1)
8.1.6
Boost Diode (D2)
8.1.7
Boost Capacitor (C3)
8.1.8
Power Loss Estimation
8.2
Typical Applications
8.2.1
VBOOST Derived from VIN (VIN = 5 V, IF = 1 A)
8.2.1.1
Design Requirements
8.2.1.2
Detailed Design Procedure
8.2.1.2.1
Calculate Duty Cycle (D)
8.2.1.2.2
Choose Capacitor Values (C1, C2, C3, and C4)
8.2.1.2.3
Set the Nominal LED Current (R1)
8.2.1.2.4
Choose Diodes (D1 and D2)
8.2.1.2.5
Calculate the Inductor Value (L1)
8.2.1.3
Application Curve
8.3
System Examples
8.3.1
VBOOST Derived From VOUT (VIN = 12 V, IF = 1 A)
8.3.1.1
Bill of Materials
8.3.2
VBOOST Derived From VIN Through a Series Zener Diode, D3 (VIN = 15 V, IF = 1 A)
8.3.2.1
Bill of Materials
8.3.3
VBOOST Derived From VIN Through a Shunt Zener Diode, D3 (VIN = 15 V, IF = 1 A)
8.3.3.1
Bill of Materials
8.3.4
VBOOST Derived from VOUT Through a Series Zener Diode, D3 (VIN = 15 V, IF = 1 A)
8.3.4.1
Bill of Materials
9
Power Supply Recommendations
10
Layout
10.1
Layout Guidelines
10.2
Layout Example
11
Device and Documentation Support
11.1
Documentation Support
11.1.1
Related Documentation
11.2
Receiving Notification of Documentation Updates
11.3
Community Resource
11.4
Trademarks
11.5
Electrostatic Discharge Caution
11.6
Glossary
12
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
DDC|6
MPDS124I
Thermal pad, mechanical data (Package|Pins)
Orderable Information
snvs429c_oa
snvs429c_pm