JAJSHT2C
august 2019 – december 2020
UCC28740-Q1
PRODUCTION DATA
1
1
特長
2
アプリケーション
3
概要
4
Revision History
5
Revision History
6
Revision History
7
Pin Configuration and Functions
7.1
Pin Functions
8
Specifications
8.1
Absolute Maximum Ratings
8.2
ESD Ratings
8.3
Recommended Operating Conditions
8.4
Thermal Information
8.5
Electrical Characteristics
8.6
Switching Characteristics
8.7
Typical Characteristics
9
Detailed Description
9.1
Overview
9.2
Functional Block Diagram
9.3
Feature Description
9.3.1
Detailed Pin Description
9.3.2
Valley-Switching and Valley-Skipping
9.3.3
Startup Operation
9.3.4
Fault Protection
9.4
Device Functional Modes
9.4.1
Secondary-Side Optically Coupled Constant-Voltage (CV) Regulation
9.4.2
Primary-Side Constant-Current (CC) Regulation
10
Application and Implementation
10.1
Application Information
10.2
High Voltage Applications
10.3
Typical Application
10.3.1
Design Requirements
10.3.2
Detailed Design Procedure
10.3.2.1
Custom Design With WEBENCH® Tools
10.3.2.2
Standby Power Estimate and No-Load Switching Frequency
10.3.2.3
Input Bulk Capacitance and Minimum Bulk Voltage
10.3.2.4
38
10.3.2.5
Transformer Turns-Ratio, Inductance, Primary Peak Current
10.3.2.6
Transformer Parameter Verification
10.3.2.7
VS Resistor Divider, Line Compensation
10.3.2.8
Output Capacitance
10.3.2.9
VDD Capacitance, CVDD
10.3.2.10
Feedback Network Biasing
10.3.3
Application Curves
11
Power Supply Recommendations
12
Layout
12.1
Layout Guidelines
12.1.1
VDD Pin
12.1.2
VS Pin
12.1.3
FB Pin
12.1.4
GND Pin
12.1.5
CS Pin
12.1.6
DRV Pin
12.1.7
HV Pin
12.2
Layout Example
13
Device and Documentation Support
13.1
Device Support
13.1.1
Development Support
13.1.1.1
Custom Design With WEBENCH® Tools
13.1.2
Device Nomenclature
13.1.2.1
Capacitance Terms in Farads
13.1.2.2
Duty Cycle Terms
13.1.2.3
Frequency Terms in Hertz
13.1.2.4
Current Terms in Amperes
13.1.2.5
Current and Voltage Scaling Terms
13.1.2.6
Transformer Terms
13.1.2.7
Power Terms in Watts
13.1.2.8
Resistance Terms in Ohms
13.1.2.9
Timing Terms in Seconds
13.1.2.10
Voltage Terms in Volts
13.1.2.11
AC Voltage Terms in VRMS
13.1.2.12
Efficiency Terms
13.2
Documentation Support
13.2.1
Related Documentation
13.3
Receiving Notification of Documentation Updates
13.4
Community Resources
13.5
Trademarks
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)
D|7
MPDS347D
サーマルパッド・メカニカル・データ
発注情報
jajsht2c_oa
13.1.2.12
Efficiency Terms
η
The converter overall efficiency at full-power output.
η
SB
The estimated efficiency of the converter at no-load condition, excluding startup resistance or bias losses. For a 5-V USB-charger application, 60% to 65% is a good initial estimate.
η
XFMR
The transformer primary-to-secondary power-transfer efficiency.