SNVSB73
September 2018
LM2735-Q1
PRODUCTION DATA.
1
Features
2
Applications
3
Description
Device Images
Typical Boost Application Circuit
Efficiency vs Load Current VO = 12 V
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
Typical Characteristics
7
Detailed Description
7.1
Overview
7.1.1
Theory of Operation
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Current Limit
7.3.2
Thermal Shutdown
7.3.3
Soft Start
7.3.4
Compensation
7.4
Device Functional Modes
7.4.1
Enable Pin and Shutdown Mode
8
Application and Implementation
8.1
Application Information
8.2
Typical Applications
8.2.1
LM2735X-Q1 SOT-23 Design Example 1
8.2.1.1
Design Requirements
8.2.1.2
Detailed Design Procedure
8.2.1.2.1
Custom Design With WEBENCH® Tools
8.2.1.2.2
Inductor Selection
8.2.1.2.3
Input Capacitor
8.2.1.2.4
Output Capacitor
8.2.1.2.5
Setting the Output Voltage
8.2.1.3
Application Curves
8.2.2
LM2735Y-Q1 SOT-23 Design Example 2
8.2.3
LM2735X-Q1 WSON Design Example 3
8.2.4
LM2735Y-Q1 WSON Design Example 4
8.2.5
LM2735X-Q1 SOT-23 Design Example 6
8.2.6
LM2735Y-Q1 SOT-23 Design Example 7
8.2.7
LM2735X-Q1 SOT-23 Design Example 8
8.2.8
LM2735Y-Q1 SOT-23 Design Example 9
8.2.9
LM2735X-Q1 WSON Design Example 10
8.2.10
LM2735Y-Q1 WSON Design Example 11
8.2.11
LM2735X-Q1 WSON SEPIC Design Example 12
8.2.12
LM2735X-Q1 SOT-23 LED Design Example 14
8.2.13
LM2735Y-Q1 WSON FlyBack Design Example 15
8.2.14
LM2735X-Q1 SOT-23 LED Design Example 16 VRAIL > 5.5 V Application
8.2.15
LM2735X-Q1 SOT-23 LED Design Example 17 Two-Input Voltage Rail Application
8.2.16
SEPIC Converter
8.2.16.1
Detailed Design Procedure
8.2.16.1.1
SEPIC Design Guide
8.2.16.1.2
Small Ripple Approximation
8.2.16.1.3
Steady State Analysis With Loss Elements
9
Power Supply Recommendations
10
Layout
10.1
Layout Guidelines
10.1.1
WSON Package
10.2
Layout Examples
10.3
Thermal Considerations
10.3.1
Definitions
10.3.2
PCB Design With Thermal Performance in Mind
10.3.3
LM2735-Q1 Thermal Models
10.3.4
Calculating Efficiency, and Junction Temperature
10.3.4.1
Example Efficiency Calculation
10.3.5
Calculating RθJA and RΨJC
10.3.5.1
Procedure
10.3.5.2
Example From Previous Calculations
11
Device and Documentation Support
11.1
Device Support
11.1.1
Third-Party Products Disclaimer
11.2
Custom Design With WEBENCH® Tools
11.3
Documentation Support
11.3.1
Related Documentation
11.4
Receiving Notification of Documentation Updates
11.5
Community Resources
11.6
Trademarks
11.7
Electrostatic Discharge Caution
11.8
Glossary
12
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
NGG|6
MPDS395
DBV|5
MPDS018T
Thermal pad, mechanical data (Package|Pins)
Orderable Information
snvsb73_oa
6.6
Typical Characteristics
Figure 1.
Current Limit vs Temperature
Figure 3.
Oscillator Frequency vs Temperature - "X"
Figure 5.
Typical Maximum Output Current vs V
IN
V
O
= 20 V
Figure 7.
LM2735-Q1X Efficiency vs Load Current
V
O
= 12 V
Figure 9.
LM2735-Q1X Efficiency vs Load Current
Figure 11.
Output Voltage Load Regulation
Figure 2.
FB Pin Voltage vs Temperature
Figure 4.
Oscillator Frequency vs Temperature - "Y"
Figure 6.
R
DSON
vs Temperature
V
O
= 20 V
Figure 8.
LM2735-Q1Y Efficiency vs Load Current
V
O
= 12 V
Figure 10.
LM2735-Q1Y Efficiency vs Load Current
Figure 12.
Output Voltage Line Regulation