SLVSB97E July   2012  – January 2018 TPS23751 , TPS23752

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
    1.     Device Images
      1. 3.1 Typical Application Circuit
  4. Revision History
  5. Pin Configuration and Functions
    1.     Pin Functions
  6. Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 ESD Ratings: Surge
    4. 6.4 Recommended Operating Conditions
    5. 6.5 Thermal Information
    6. 6.6 Electric Characteristics - Controller Section
    7. 6.7 Electrical Characteristics - Sleep Mode (TPS23752 Only)
    8. 6.8 Electrical Characteristics - PoE Interface Section
    9. 6.9 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagrams
    3. 7.3 Feature Description
      1. 7.3.1 Pin Description
    4. 7.4 Device Functional Modes
      1. 7.4.1 PoE Overview
        1. 7.4.1.1 Threshold Voltages
        2. 7.4.1.2 PoE Startup Sequence
        3. 7.4.1.3 Detection
        4. 7.4.1.4 Hardware Classification
        5. 7.4.1.5 Inrush and Startup
        6. 7.4.1.6 Maintain Power Signature
        7. 7.4.1.7 Startup and Converter Operation
        8. 7.4.1.8 PD Hotswap Operation
      2. 7.4.2 Sleep Mode Operation (TPS23752 only)
        1. 7.4.2.1  Converter Controller Features
        2. 7.4.2.2  PWM and VFO Operation; CTL, SRT, and SRD Pin Relationships to Output Load Current
        3. 7.4.2.3  Bootstrap Topology
        4. 7.4.2.4  Current Slope Compensation and Current Limit
        5. 7.4.2.5  RT
        6. 7.4.2.6  T2P, Startup and Power Management
        7. 7.4.2.7  Thermal Shutdown
        8. 7.4.2.8  Adapter ORing
        9. 7.4.2.9  Using DEN to Disable PoE
        10. 7.4.2.10 ORing Challenges
  8. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1  Input Bridges and Schottky Diodes
        2. 8.2.2.2  Protection, D1
        3. 8.2.2.3  Capacitor, C1
        4. 8.2.2.4  Detection Resistor, RDEN
        5. 8.2.2.5  Classification Resistor, RCLS
        6. 8.2.2.6  APD Pin Divider Network, RAPD1, RAPD2
        7. 8.2.2.7  Setting the PWM-VFO Threshold using the SRT pin
        8. 8.2.2.8  Setting Frequency (RT)
        9. 8.2.2.9  Current Slope Compensation
        10. 8.2.2.10 Voltage Feed-Forward Compensation
        11. 8.2.2.11 Estimating Bias Supply Requirements and Cvc
        12. 8.2.2.12 Switching Transformer Considerations and RVC
        13. 8.2.2.13 T2P Pin Interface
        14. 8.2.2.14 Softstart
        15. 8.2.2.15 Special Switching MOSFET Considerations
        16. 8.2.2.16 ESD
        17. 8.2.2.17 Thermal Considerations and OTSD
      3. 8.2.3 Application Curves
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
      2. 11.1.2 Related Links
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Electrical Characteristics - PoE Interface Section

Unless otherwise noted, 40 V ≤ VDD ≤ 57 V; VCTL = VMODE = VSLPb = VB; VSRT = 0.5 V; VAPD = VCS = VARTN = VRTN; CLS, GATE, LED, SRD, T2P open; RWAKE = 392 kΩ; RDEN = 24.9 kΩ; RT = 34 kΩ; CVB = CVC = 0.1 µF;
–40 ≤ TJ ≤ 125°C. Typical values are at 25°C. All voltages referred to VSS.
Unless otherwise noted, VVC = VAPD = VCS = VARTN = VRTN.
PARAMETERTEST CONDITIONSMINTYPMAXUNIT
DEN (DETECTION AND ENABLE)
Bias current DEN open, IVDD + IDEN + IRTN, VVDD = 10.1 V, not in mark 3 5 12 µA
DEN leakage current VDEN = VVDD = 57 V 0.1 5 µA
Detection current IVDD + IDEN + IRTN, VVDD = 1.4 V 53.8 56.5 58.3 µA
IVDD + IDEN + IRTN, VVDD = 10.1 V 395 410 417
VPD_DIS Disable threshold DEN falling 3 3.6 5 V
Hysteresis 50 113 200 mV
CLS (CLASSIFICATION)
ICLS Classification current 13 V ≤ VVDD ≤ 21 V, Measure IVDD + IDEN + IRTN mA
RCLS = 1270 Ω 1.80 2.17 2.60
RCLS = 243 Ω 9.90 10.60 11.20
RCLS = 137 Ω 17.60 18.60 19.40
RCLS = 90.9 Ω 26.50 27.90 29.30
RCLS = 63.4 Ω 38.00 39.90 42.00
VCL_ON
VCL_H
Class lower threshold VVDD rising, VCLS 11.9 12.5 13 V
Hysteresis 1.4 1.6 1.7 V
VCU_OFF
VCU_H
Class upper threshold VVDD rising, VCLS 21 22 23 V
Hysteresis 0.50 0.75 0.90 V
VMSR Mark reset threshold VVDD falling 3 3.9 5 V
Mark state resistance 2-point measurement at 5 V and 10.1 V 6 9.1 12
Leakage current VVDD = 57 V, VCLS = 0 V, measure ICLS 1 µA
RTN (PASS DEVICE)
rDS(on) On resistance VVC = VAPD = VARTN = VCS = VVDD 0.20 0.45 0.75 Ω
Current limit VVC = VAPD = VARTN = VCS = VVDD, VRTN =1.5 V, Measure IRTN 0.85 1.00 1.20 A
Inrush current VVC = VAPD = VARTN = VCS = VDD, VRTN = 2 V, VDD = 20 V → 48 V 100 140 180 mA
Inrush termination Percentage of inrush current 80% 90% 99%
Foldback threshold VRTN 11.0 12.3 13.6 V
Foldback deglitch time VRTN rising to when current limit changes to inrush current limit 500 800 1500 µs
Input bias current VVDD = VRTN = 30 V, Measure IRTN 30 µA
RTN leakage current VRTN = VVDD = 100 V, VDEN = VVSS 50 µA
T2P (TYPE 2 PSE INDICATION)
VT2P Output low voltage IT2P = 2 mA, after 2-event classification and softstart is complete,
VVC = 12 V, VCTL = 3 V, VARTN = VVSS
0.26 0.60 V
tT2P T2P startup delay VCTL = 3 V, VAPD = 2 V, Measure from switching start to VT2P 2 4.3 7 ms
Leakage current VT2P = 18 V, VARTN = VVSS 10 µA
PoE – PD UVLO
VUVLO_R UVLO rising threshold 36.3 38.1 40 V
UVLO falling threshold 30.5 32.0 33.6
SUPPLY CURRENT
Operating current Measure IVDD, VVDD = 48 V, 40 V ≤ VVDD ≤ 57 V 210 500 µA
Off-state current ARTN and VVC open, VVDD = 30 V, Measure IVDD 300 µA
THERMAL SHUTDOWN
Shutdown TJ rising 135 145 155 °C
Hysteresis (1) 20 °C
Parameters provided for reference only, and do not constitute part of TI published specifications for purposes of TI product warranty.
TPS23751 TPS23752 Curr_Mode_Comp_Ramp_SLVSB97.gifFigure 1. Current Mode Compensation Ramp
TPS23751 TPS23752 Time_Delay_SLVSB97.gifFigure 2. Time Delay from VCS to VGATE
TPS23751 TPS23752 Rise_Fall_Time_SLVSB97.gifFigure 3. Rise Time and Fall Time of VGATE