SLVSB97E
July 2012 – January 2018
TPS23751
,
TPS23752
PRODUCTION DATA.
1
Features
2
Applications
3
Description
Device Images
3.1
Typical Application Circuit
4
Revision History
5
Pin Configuration and Functions
Pin Functions
6
Specifications
6.1
Absolute Maximum Ratings
6.2
ESD Ratings
6.3
ESD Ratings: Surge
6.4
Recommended Operating Conditions
6.5
Thermal Information
6.6
Electric Characteristics - Controller Section
6.7
Electrical Characteristics - Sleep Mode (TPS23752 Only)
6.8
Electrical Characteristics - PoE Interface Section
6.9
Typical Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagrams
7.3
Feature Description
7.3.1
Pin Description
7.4
Device Functional Modes
7.4.1
PoE Overview
7.4.1.1
Threshold Voltages
7.4.1.2
PoE Startup Sequence
7.4.1.3
Detection
7.4.1.4
Hardware Classification
7.4.1.5
Inrush and Startup
7.4.1.6
Maintain Power Signature
7.4.1.7
Startup and Converter Operation
7.4.1.8
PD Hotswap Operation
7.4.2
Sleep Mode Operation (TPS23752 only)
7.4.2.1
Converter Controller Features
7.4.2.2
PWM and VFO Operation; CTL, SRT, and SRD Pin Relationships to Output Load Current
7.4.2.3
Bootstrap Topology
7.4.2.4
Current Slope Compensation and Current Limit
7.4.2.5
RT
7.4.2.6
T2P, Startup and Power Management
7.4.2.7
Thermal Shutdown
7.4.2.8
Adapter ORing
7.4.2.9
Using DEN to Disable PoE
7.4.2.10
ORing Challenges
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
Input Bridges and Schottky Diodes
8.2.2.2
Protection, D1
8.2.2.3
Capacitor, C1
8.2.2.4
Detection Resistor, RDEN
8.2.2.5
Classification Resistor, RCLS
8.2.2.6
APD Pin Divider Network, RAPD1, RAPD2
8.2.2.7
Setting the PWM-VFO Threshold using the SRT pin
8.2.2.8
Setting Frequency (RT)
8.2.2.9
Current Slope Compensation
8.2.2.10
Voltage Feed-Forward Compensation
8.2.2.11
Estimating Bias Supply Requirements and Cvc
8.2.2.12
Switching Transformer Considerations and RVC
8.2.2.13
T2P Pin Interface
8.2.2.14
Softstart
8.2.2.15
Special Switching MOSFET Considerations
8.2.2.16
ESD
8.2.2.17
Thermal Considerations and OTSD
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
Documentation Support
11.1.1
Related Documentation
11.1.2
Related Links
11.2
Community Resources
11.3
Trademarks
11.4
Electrostatic Discharge Caution
11.5
Glossary
12
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
PWP|16
MPDS371A
Thermal pad, mechanical data (Package|Pins)
PWP|16
PPTD312C
Orderable Information
slvsb97e_oa
slvsb97e_pm
6.9
Typical Characteristics
Figure 4.
Supply Current vs Supply Voltage
Figure 6.
CS VFO Peak Voltage vs SRT Voltage
Figure 8.
CS Ramp Current vs Temperature
Figure 10.
VC Bootstrap Current Source vs Supply Voltage
Figure 12.
Switching Frequency vs Temperature
Figure 14.
VFO Frequency vs CTL Voltage
Figure 16.
rDS(on) vs Temperature
Figure 18.
MPS Supply Current vs Supply Voltage
Figure 5.
DEN BIas Current vs Supply Voltage
Figure 7.
VC Operating Current vs VC Voltage
Figure 9.
VC Voltage in Sleep Mode vs Temperature
Figure 11.
CTL PWM/VFO Threshold vs SRT Voltage
Figure 13.
Switching Frequency vs Programmable Conductance
Figure 15.
Blanking Period vs Temperature
Figure 17.
MPS Supply Current vs LED Current