JAJSRX9C January   2012  – November 2023 TPS40170-Q1

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 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  LDO Linear Regulators and Enable
      2. 6.3.2  Input Undervoltage Lockout (UVLO)
      3. 6.3.3  Equations for Programming the Input UVLO
      4. 6.3.4  Overcurrent Protection and Short-Circuit Protection (OCP and SCP)
      5. 6.3.5  Oscillator and Voltage Feed-Forward
        1. 6.3.5.1 Calculating the Timing Resistance (RRT)
      6. 6.3.6  Feed-Forward Oscillator Timing Diagram
      7. 6.3.7  Soft-Start and Fault-Logic
        1. 6.3.7.1 Soft-Start During Overcurrent Fault
        2. 6.3.7.2 Equations for Soft-Start and Restart Time
      8. 6.3.8  Overtemperature Fault
      9. 6.3.9  Tracking
      10. 6.3.10 Adaptive Drivers
      11. 6.3.11 Start-Up Into Pre-Biased Output
      12. 6.3.12 31
      13. 6.3.13 Power Good (PGOOD)
      14. 6.3.14 PGND and AGND
      15. 6.3.15 Bootstrap Capacitor
      16. 6.3.16 Bypass and Filtering
    4. 6.4 Device Functional Modes
      1. 6.4.1 Frequency Synchronization
  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  Select A Switching Frequency
        2. 7.2.2.2  Inductor Selection (L1)
        3. 7.2.2.3  Output Capacitor Selection (C9)
        4. 7.2.2.4  Peak Current Rating of Inductor
        5. 7.2.2.5  Input Capacitor Selection (C1, C6)
        6. 7.2.2.6  MOSFET Switch Selection (Q1, Q2)
        7. 7.2.2.7  Timing Resistor (R7)
        8. 7.2.2.8  UVLO Programming Resistors (R2, R6)
        9. 7.2.2.9  Bootstrap Capacitor (C7)
        10. 7.2.2.10 VIN Bypass Capacitor (C18)
        11. 7.2.2.11 VBP Bypass Capacitor (C19)
        12. 7.2.2.12 SS Timing Capacitor (C15)
        13. 7.2.2.13 ILIM Resistor (R19, C17)
        14. 7.2.2.14 SCP Multiplier Selection (R5)
        15. 7.2.2.15 Feedback Divider (R10, R11)
        16. 7.2.2.16 Compensation: (R4, R13, C13, C14, C21)
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
      1. 7.3.1 Bootstrap Resistor
      2. 7.3.2 SW-Node Snubber Capacitor
      3. 7.3.3 Input Resistor
      4. 7.3.4 LDRV Gate Capacitor
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 サード・パーティ製品に関する免責事項
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 ドキュメントの更新通知を受け取る方法
    4. 8.4 サポート・リソース
    5. 8.5 Trademarks
    6. 8.6 静電気放電に関する注意事項
    7. 8.7 用語集
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

7.2.2.7 Timing Resistor (R7)

The switching frequency is programmed by the current through RRT to GND. The RRT value is calculated using Equation 34.

Equation 34. GUID-C3AA7A9D-6A8E-4159-B843-BBFF500E59A3-low.gif