JAJSK02
October 2020
TPS23731
PRODUCTION DATA
1
特長
2
アプリケーション
3
概要
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: DC-DC Controller Section
7.6
Electrical Characteristics PoE
14
7.7
Typical Characteristics
8
Detailed Description
8.1
Overview
8.2
Functional Block Diagram
8.3
Feature Description
8.3.1
CLS Classification
8.3.2
DEN Detection and Enable
8.3.3
APD Auxiliary Power Detect
8.3.4
Internal Pass MOSFET
8.3.5
T2P and APDO Indicators
8.3.6
DC-DC Controller Features
8.3.6.1
VCC, VB, VBG and Advanced PWM Startup
27
8.3.6.2
CS, Current Slope Compensation and blanking
8.3.6.3
COMP, FB, EA_DIS, CP, PSRS and Opto-less Feedback
8.3.6.4
FRS Frequency Setting and Synchronization
8.3.6.5
DTHR and Frequency Dithering for Spread Spectrum Applications
8.3.6.6
SST and Soft-Start of the Switcher
8.3.6.7
SST, I_STP, LINEUV and Soft-Stop of the Switcher
8.3.7
Switching FET Driver - GATE
8.3.8
EMPS and Automatic MPS
8.3.9
VDD Supply Voltage
8.3.10
RTN, AGND, GND
8.3.11
VSS
8.3.12
Exposed Thermal pads - PAD_G and PAD_S
8.4
Device Functional Modes
8.4.1
PoE Overview
8.4.2
Threshold Voltages
8.4.3
PoE Start-Up Sequence
8.4.4
Detection
8.4.5
Hardware Classification
8.4.6
Maintain Power Signature (MPS)
8.4.7
Advanced Start-Up and Converter Operation
8.4.8
Line Undervoltage Protection and Converter Operation
8.4.9
PD Self-Protection
8.4.10
Thermal Shutdown - DC-DC Controller
8.4.11
Adapter ORing
9
Application and Implementation
9.1
Application Information
9.2
Typical Application
9.2.1
Design Requirements
9.2.1.1
Detailed Design Procedure
9.2.1.1.1
Input Bridges and Schottky Diodes
9.2.1.1.2
Input TVS Protection
9.2.1.1.3
Input Bypass Capacitor
9.2.1.1.4
Detection Resistor, RDEN
9.2.1.1.5
Classification Resistor, RCLS.
9.2.1.1.6
APD Pin Divider Network, RAPD1, RAPD2
9.2.1.1.7
Setting Frequency (RFRS) and Synchronization
9.2.1.1.8
Bias Supply Requirements and CVCC
9.2.1.1.9
APDO, T2P Interface
9.2.1.1.10
Output Voltage Feedback Divider, RAUX, R1,R2
9.2.1.1.11
Frequency Dithering for Conducted Emissions Control
10
Power Supply Recommendations
11
Layout
11.1
Layout Guidelines
11.2
Layout Example
11.3
EMI Containment
11.4
Thermal Considerations and OTSD
11.5
ESD
12
Device and Documentation Support
12.1
Documentation Support
12.1.1
Related Documentation
12.2
サポート・リソース
12.3
Trademarks
12.4
静電気放電に関する注意事項
12.5
用語集
13
Mechanical, Packaging, and Orderable Information