SNVS602L
March 2009 – June 2016
LM3409
,
LM3409-Q1
,
LM3409HV
,
LM3409HV-Q1
PRODUCTION DATA.
1
Features
2
Applications
3
Description
4
Revision History
5
Device Comparison Table
6
Pin Configuration and Functions
7
Specifications
7.1
Absolute Maximum Ratings
7.2
ESD Ratings
7.3
Recommended Operating Conditions
7.4
Thermal Information
7.5
Electrical Characteristics
7.6
Typical Characteristics
8
Detailed Description
8.1
Overview
8.2
Functional Block Diagram
8.3
Feature Description
8.3.1
Buck Current Regulators
8.3.2
Controlled Off-Time (COFT) Architecture
8.3.2.1
Adjustable Peak Current Control
8.3.2.2
Controlled Off-Time
8.3.3
Average LED Current
8.3.4
Inductor Current Ripple
8.3.5
Switching Frequency
8.3.6
PWM Dimming Using the EN Pin
8.3.7
High Voltage Negative BIAS Regulator
8.3.8
External Parallel FET PWM Dimming
8.4
Device Functional Modes
8.4.1
Low-Power Shutdown
8.4.2
Thermal Shutdown
9
Application and Implementation
9.1
Application Information
9.1.1
Input Undervoltage Lockout (UVLO)
9.1.2
Operation Near Dropout
9.1.3
LED Ripple Current
9.1.4
Buck Converters without Output Capacitors
9.1.5
Buck Converters With Output Capacitors
9.1.6
Output Overvoltage Protection
9.1.7
Input Capacitors
9.1.8
P-Channel MOSFET (PFET)
9.1.9
Re-Circulating Diode
9.2
Typical Applications
9.2.1
EN PIN PWM Dimming Application for 10 LEDs
9.2.1.1
Design Requirements
9.2.1.2
Detailed Design Procedure
9.2.1.2.1
Nominal Switching Frequency
9.2.1.2.2
Inductor Ripple Current
9.2.1.2.3
Average LED Current
9.2.1.2.4
Output Capacitance
9.2.1.2.5
Input Capacitance
9.2.1.2.6
PFET
9.2.1.2.7
Diode
9.2.1.2.8
Input UVLO
9.2.1.2.9
IADJ Connection Method
9.2.1.2.10
PWM Dimming Method
9.2.1.3
Application Curve
9.2.2
Analog Dimming Application for 4 LEDs
9.2.2.1
Design Requirements
9.2.2.2
Detailed Design Procedure
9.2.2.2.1
Nominal Switching Frequency
9.2.2.2.2
Inductor Ripple Current
9.2.2.2.3
Average LED Current
9.2.2.2.4
Output Capacitance
9.2.2.2.5
Input Capacitance
9.2.2.2.6
PFET
9.2.2.2.7
Diode
9.2.2.2.8
Input UVLO
9.2.2.2.9
IADJ Connection Method
9.2.2.2.10
PWM Dimming Method
9.2.2.3
Application Curve
9.2.3
LM3409 Buck Converter Application
9.2.3.1
Design Requirements
9.2.3.2
Detailed Design Procedure
9.2.3.2.1
Nominal Switching Frequency
9.2.3.2.2
Inductor Ripple Current
9.2.3.2.3
Average LED Current
9.2.3.2.4
Output Capacitance
9.2.3.2.5
Input Capacitance
9.2.3.2.6
PFET
9.2.3.2.7
Diode
9.2.3.2.8
Input UVLO
9.2.3.2.9
IADJ Connection Method
9.2.3.2.10
PWM Dimming Method
10
Power Supply Recommendations
11
Layout
11.1
Layout Guidelines
11.2
Layout Example
12
Device and Documentation Support
12.1
Device Support
12.1.1
Third-Party Products Disclaimer
12.2
Related Links
12.3
Community Resources
12.4
Trademarks
12.5
Electrostatic Discharge Caution
12.6
Glossary
13
Mechanical, Packaging, and Orderable Information
パッケージ・オプション
メカニカル・データ(パッケージ|ピン)
DGQ|10
MPDS043F
NFF|14
MPDI093
サーマルパッド・メカニカル・データ
DGQ|10
PPTD275A
5 Device Comparison Table
ORDERABLE NUMBER
MAXIMUM INPUT VOLTAGE (V)
AEC-Q100 GRADE 1 QUALIFIED
LM3409
42
N
LM3409-Q1
Y
LM3409HV
75
N
LM3409HV-Q1
Y