SLUSBF3D
July 2013 – March 2018
UCC28740
PRODUCTION DATA.
1
Features
2
Applications
3
Description
Device Images
Simplified Application Diagram
Typical V-I Diagram
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
Switching Characteristics
6.7
Typical Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Detailed Pin Description
7.3.2
Valley-Switching and Valley-Skipping
7.3.3
Startup Operation
7.3.4
Fault Protection
7.4
Device Functional Modes
7.4.1
Secondary-Side Optically Coupled Constant-Voltage (CV) Regulation
7.4.2
Primary-Side Constant-Current (CC) Regulation
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
Standby Power Estimate and No-Load Switching Frequency
8.2.2.3
Input Bulk Capacitance and Minimum Bulk Voltage
8.2.2.4
Transformer Turns-Ratio, Inductance, Primary Peak Current
8.2.2.5
Transformer Parameter Verification
8.2.2.6
VS Resistor Divider, Line Compensation
8.2.2.7
Output Capacitance
8.2.2.8
VDD Capacitance, CVDD
8.2.2.9
Feedback Network Biasing
8.2.3
Application Curves
9
Power Supply Recommendations
10
Layout
10.1
Layout Guidelines
10.1.1
VDD Pin
10.1.2
VS Pin
10.1.3
FB Pin
10.1.4
GND Pin
10.1.5
CS Pin
10.1.6
DRV Pin
10.1.7
HV Pin
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
11.1.2
Device Nomenclature
11.1.2.1
Capacitance Terms in Farads
11.1.2.2
Duty Cycle Terms
11.1.2.3
Frequency Terms in Hertz
11.1.2.4
Current Terms in Amperes
11.1.2.5
Current and Voltage Scaling Terms
11.1.2.6
Transformer Terms
11.1.2.7
Power Terms in Watts
11.1.2.8
Resistance Terms in Ohms
11.1.2.9
Timing Terms in Seconds
11.1.2.10
Voltage Terms in Volts
11.1.2.11
AC Voltage Terms in VRMS
11.1.2.12
Efficiency Terms
11.2
Documentation Support
11.2.1
Related Documentation
11.3
Receiving Notification of Documentation Updates
11.4
Community Resources
11.5
Trademarks
11.6
Electrostatic Discharge Caution
11.7
Glossary
12
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
D|7
MPDS347D
Thermal pad, mechanical data (Package|Pins)
Orderable Information
slusbf3d_oa
slusbf3d_pm
11.1.2.11
AC Voltage Terms in V
RMS
V
IN(max)
The maximum input voltage to the converter.
V
IN(min)
The minimum input voltage to the converter.
V
IN(run)
The converter startup (run) input voltage.