JAJSOL2 August   2024 TPS55287

PRODUCTION DATA  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 I2C Timing Characteristics
    7. 5.7 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1  VCC Power Supply
      2. 6.3.2  EXTVCC Power Supply
      3. 6.3.3  Operation Mode Setting
      4. 6.3.4  Input Undervoltage Lockout
      5. 6.3.5  Enable and Programmable UVLO
      6. 6.3.6  Soft Start
      7. 6.3.7  Shutdown and Load Discharge
      8. 6.3.8  Switching Frequency
      9. 6.3.9  Switching Frequency Dithering
      10. 6.3.10 Inductor Current Limit
      11. 6.3.11 Internal Charge Path
      12. 6.3.12 Output Voltage Setting
      13. 6.3.13 Output Current Monitoring and Cable Voltage Droop Compensation
      14. 6.3.14 Output Current Limit
      15. 6.3.15 Overvoltage Protection
      16. 6.3.16 Output Short Circuit Protection
      17. 6.3.17 Thermal Shutdown
    4. 6.4 Device Functional Modes
      1. 6.4.1 PWM Mode
      2. 6.4.2 Power Save Mode
    5. 6.5 Programming
      1. 6.5.1 Data Validity
      2. 6.5.2 START and STOP Conditions
      3. 6.5.3 Byte Format
      4. 6.5.4 Acknowledge (ACK) and Not Acknowledge (NACK)
      5. 6.5.5 Target Address and Data Direction Bit
      6. 6.5.6 Single Read and Write
      7. 6.5.7 Multiread and Multiwrite
    6. 6.6 Register Maps
      1. 6.6.1 REF Register (Address = 0h, 1h)
      2. 6.6.2 IOUT_LIMIT Register (Address = 2h) [reset = 11100100h]
      3. 6.6.3 VOUT_SR Register (Address = 3h) [reset = 00000001h]
      4. 6.6.4 VOUT_FS Register (Address = 4h) [reset = 00000011h]
      5. 6.6.5 CDC Register (Address = 5h) [reset = 11100000h]
      6. 6.6.6 MODE Register (Address = 6h) [reset = 00100000h]
      7. 6.6.7 STATUS Register (Address = 7h) [reset = 00000011h]
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Switching Frequency
        2. 7.2.2.2 Output Voltage Setting
        3. 7.2.2.3 Inductor Selection
        4. 7.2.2.4 Input Capacitor
        5. 7.2.2.5 Output Capacitor
        6. 7.2.2.6 Output Current Limit
        7. 7.2.2.7 Loop Stability
      3. 7.2.3 Application Curves
  9. 8 Power Supply Recommendations
  10. 9 Layout
    1. 9.1 Layout Guidelines
    2. 9.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 サード・パーティ製品に関する免責事項
    2. 10.2 ドキュメントの更新通知を受け取る方法
    3. 10.3 サポート・リソース
    4. 10.4 Trademarks
    5. 10.5 静電気放電に関する注意事項
    6. 10.6 用語集
  12. 11Revision History
  13. 12Mechanical, 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）
サーマルパッド・メカニカル・データ
発注情報

7.2.2.4 Input Capacitor

In buck mode, the input capacitor supplies high ripple current. The RMS current in the input capacitors is given by Equation 14.

Equation 14. TPS55287

where

  • ICIN(RMS) is the RMS current through the input capacitor.
  • IOUT is the output current.

The maximum RMS current occurs at the output voltage is half of the input voltage, which gives ICIN(RMS) = IOUT / 2. Ceramic capacitors are recommended for their low ESR and high ripple current capability. A total of 20 µF effective capacitance is a good starting point for this application. Add a 0.1-µF/0402 package ceramic capacitor and place it close to VIN pin and GND pin to suppress high frequency noise.