JAJSEO7I October   2008  – December 2017 TPS23754 , TPS23754-1 , TPS23756

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      TPS23754を使用する高効率コンバータ
  4. 4 改訂履歴
  5. 5 概要（続き）
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Electrical Characteristics: PoE and Control
    7. 7.7 Switching Characteristics
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  APD
      2. 8.3.2  BLNK
      3. 8.3.3  CLS
      4. 8.3.4  Current Sense (CS)
      5. 8.3.5  Control (CTL)
      6. 8.3.6  Detection and Enable (DEN)
      7. 8.3.7  DT
      8. 8.3.8  Frequency and Synchronization (FRS)
      9. 8.3.9  GATE
      10. 8.3.10 GAT2
      11. 8.3.11 PPD
      12. 8.3.12 RTN, ARTN, COM
      13. 8.3.13 T2P
      14. 8.3.14 VB
      15. 8.3.15 VC
      16. 8.3.16 VDD
      17. 8.3.17 VDD1
      18. 8.3.18 VSS
      19. 8.3.19 PowerPAD
    4. 8.4 Device Functional Modes
      1. 8.4.1 PoE Overview
        1. 8.4.1.1  Threshold Voltages
        2. 8.4.1.2  PoE Start-Up Sequence
        3. 8.4.1.3  Detection
        4. 8.4.1.4  Hardware Classification
        5. 8.4.1.5  Inrush and Start-Up
        6. 8.4.1.6  Maintain Power Signature
        7. 8.4.1.7  Start-Up and Converter Operation
        8. 8.4.1.8  PD Hotswap Operation
        9. 8.4.1.9  Converter Controller Features
        10. 8.4.1.10 Bootstrap Topology
        11. 8.4.1.11 Current Slope Compensation and Current Limit
        12. 8.4.1.12 Blanking – RBLNK
        13. 8.4.1.13 Dead Time
        14. 8.4.1.14 FRS and Synchronization
        15. 8.4.1.15 T2P, Start-Up, and Power Management
        16. 8.4.1.16 Thermal Shutdown
        17. 8.4.1.17 Adapter ORing
        18. 8.4.1.18 PPD ORing Features
        19. 8.4.1.19 Using DEN to Disable PoE
        20. 8.4.1.20 ORing Challenges
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1  Input Bridges and Schottky Diodes
        2. 9.2.2.2  Protection, D1
        3. 9.2.2.3  Capacitor, C1
        4. 9.2.2.4  Detection Resistor, RDEN
        5. 9.2.2.5  Classification Resistor, RCLS
        6. 9.2.2.6  Dead Time Resistor, RDT
        7. 9.2.2.7  Switching Transformer Considerations and RVC
        8. 9.2.2.8  Special Switching MOSFET Considerations
        9. 9.2.2.9  Thermal Considerations and OTSD
        10. 9.2.2.10 APD Pin Divider Network, RAPD1, RAPD2
        11. 9.2.2.11 PPD Pin Divider Network, RPPD1, RPPD2
        12. 9.2.2.12 Setting Frequency (RFRS) and Synchronization
        13. 9.2.2.13 Current Slope Compensation
        14. 9.2.2.14 Blanking Period, RBLNK
        15. 9.2.2.15 Estimating Bias Supply Requirements and CVC
        16. 9.2.2.16 T2P Pin Interface
        17. 9.2.2.17 Advanced ORing Techniques
        18. 9.2.2.18 Soft Start
        19. 9.2.2.19 Frequency Dithering for Conducted Emissions Control
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 ESD
  12. 12デバイスおよびドキュメントのサポート
    1. 12.1 ドキュメントのサポート
      1. 12.1.1 関連資料
    2. 12.2 コミュニティ・リソース
    3. 12.3 商標
    4. 12.4 静電気放電に関する注意事項
    5. 12.5 Glossary
  13. 13メカニカル、パッケージ、および注文情報

パッケージ・オプション

デバイスごとのパッケージ図は、PDF版データシートをご参照ください。

メカニカル・データ（パッケージ｜ピン）
  • PWP|20
サーマルパッド・メカニカル・データ
発注情報

9.2.2.11 PPD Pin Divider Network, RPPD1, RPPD2

The PPD pin can be used to override the internal hotswap MOSFET UVLO (VUVLO_R and VUVLO_H) when using low voltage adapters connected between VDD and VSS. The PPD pin has an internal 5-μA pulldown current source. As an example, consider the choice of RPPD1 and RPPD2, for a 24-V adapter.

  1. Select the start-up voltage, VADPTR-ON approximately 75% of nominal for a 24-V adapter. Assuming that the adapter output is 24 V ± 10%, this provides 15% margin below the minimum adapter operating voltage.
  2. Choose VADPTR-ON = 24 V × 0.75 = 18 V.
  3. Choose RPPD2 = 3.01 kΩ.
  4. Calculate RPPD1.
    1. TPS23754 TPS23754-1 TPS23756 il_eq1_lvs885.gif
    2. Choose RPPD1 = 32.4 kΩ.
  5. Check PPD turnon and PPD turnoff voltages.
    1. TPS23754 TPS23754-1 TPS23756 il_eq2_lvs885.gif
    2. TPS23754 TPS23754-1 TPS23756 il_eq3_lvs885.gif
    3. Voltages look acceptable.
  6. Check PPD resistor power consumption.
    1. TPS23754 TPS23754-1 TPS23756 il_eq4_lvs885.gif
    2. Power is acceptable, but resistor values could be increased to reduce the power loss.

      3. The PPD pin can also be used to modify the internal MOSFET UVLO for use with a lower output voltage PSE (within certain limits). Connect the RPPD1 and RPPD2 dividers directly between VDD and VSS with the midpoint connected to PPD. For this case and to allow classification, target the minimum PSE OFF voltage (VADPTR_OFF) > VCU_OFF = 23 V. Then follow the procedure outlined above to select RPPD1, RPPD2, and determine the PSE ON (VADPTR_ON) and PSE OFF (VADPTR_OFF) voltages ensuring that PSE OFF > 23 V. Lastly, because the RPPD1 and RPPD2 divider is in parallel with RDEN during detection, RDEN must be increased such that the equivalent detection resistance is 25 kΩ nominal.