SNVS847F
June 2012 – November 2017
LM34926
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 Ratings
6.4
Thermal Information
6.5
Electrical Characteristics
6.6
Switching Characteristics
6.7
Typical Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Control Overview
7.3.2
VCC Regulator
7.3.3
Regulation Comparator
7.3.4
Overvoltage Comparator
7.3.5
On-Time Generator
7.3.6
Current Limit
7.3.7
N-Channel Buck Switch and Driver
7.3.8
Synchronous Rectifier
7.3.9
Undervoltage Detector
7.3.10
Thermal Protection
7.3.11
Ripple Configuration
7.3.12
Soft Start
7.4
Device Functional Modes
8
Application and Implementation
8.1
Application Information
8.2
Typical Application
8.2.1
Design Requirements
8.2.2
Detailed Design Procedure
8.2.2.1
Custom Design With WEBENCH® Tools
8.2.2.2
Transformer Turns Ratio
8.2.2.3
Total IOUT
8.2.2.4
RFB1, RFB2
8.2.2.5
Frequency Selection
8.2.2.6
Transformer Selection
8.2.2.7
Primary Output Capacitor
8.2.2.8
Secondary Output Capacitor
8.2.2.9
Type III Feedback Ripple Circuit
8.2.2.10
Secondary Diode
8.2.2.11
VCC and Bootstrap Capacitor
8.2.2.12
Input Capacitor
8.2.2.13
UVLO Resistors
8.2.2.14
VCC Diode
8.2.3
Application Curves
9
Power Supply Recommendations
10
Layout
10.1
Layout Guidelines
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)
DDA|8
MPDS092F
NGU|8
MPDS407A
Thermal pad, mechanical data (Package|Pins)
DDA|8
PPTD058J
Orderable Information
snvs847f_oa
snvs847f_pm