JAJSJO5A October   2022  – October 2023 LM64460-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 Revision History
  6. 5 Device Comparison Table
  7. 6 Pin Configuration and Functions
    1. 6.1 Wettable Flanks
    2. 6.2 Pinout Design for Clearance and FMEA
  8. 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 Timing Characteristics
    7. 7.7 Systems Characteristics
    8. 7.8 Typical Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Input Voltage Range (VIN1, VIN2)
      2. 8.3.2  Output Voltage Setpoint (FB)
      3. 8.3.3  Precision Enable and Input Voltage UVLO (EN)
      4. 8.3.4  MODE/SYNC Operation
        1. 8.3.4.1 Level-Dependent MODE/SYNC Control
        2. 8.3.4.2 Pulse-Dependent MODE/SYNC Control
      5. 8.3.5  Clock Locking
      6. 8.3.6  Power-Good Monitor (PGOOD)
      7. 8.3.7  Bias Supply Regulator (VCC, BIAS)
      8. 8.3.8  Bootstrap Voltage and UVLO (CBOOT)
      9. 8.3.9  Spread Spectrum
      10. 8.3.10 Soft Start and Recovery From Dropout
      11. 8.3.11 Overcurrent and Short-Circuit Protection
      12. 8.3.12 Thermal Shutdown
      13. 8.3.13 Input Supply Current
    4. 8.4 Device Functional Modes
      1. 8.4.1 Shutdown Mode
      2. 8.4.2 Standby Mode
      3. 8.4.3 Active Mode
        1. 8.4.3.1 CCM Mode
        2. 8.4.3.2 AUTO Mode – Light-Load Operation
          1. 8.4.3.2.1 Diode Emulation
          2. 8.4.3.2.2 Frequency Foldback
        3. 8.4.3.3 FPWM Mode – Light-Load Operation
        4. 8.4.3.4 Minimum On-Time (High Input Voltage) Operation
        5. 8.4.3.5 Dropout
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Design 1 – Automotive Synchronous Buck Regulator at 2.1 MHz
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1  Custom Design With WEBENCH® Tools
          2. 9.2.1.2.2  Setting the Output Voltage
          3. 9.2.1.2.3  Choosing the Switching Frequency
          4. 9.2.1.2.4  Inductor Selection
          5. 9.2.1.2.5  Output Capacitor Selection
          6. 9.2.1.2.6  Input Capacitor Selection
          7. 9.2.1.2.7  Bootstrap Capacitor
          8. 9.2.1.2.8  VCC Capacitor
          9. 9.2.1.2.9  BIAS Power Connection
          10. 9.2.1.2.10 Feedforward Network
          11. 9.2.1.2.11 Input Voltage UVLO
        3. 9.2.1.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
        1. 9.4.1.1 Thermal Design and Layout
      2. 9.4.2 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. 10.1.2 Development Support
        1. 10.1.2.1 Custom Design With WEBENCH® Tools
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 ドキュメントの更新通知を受け取る方法
    4. 10.4 サポート・リソース
    5. 10.5 Trademarks
    6. 10.6 静電気放電に関する注意事項
    7. 10.7 用語集
  12. 11Mechanical, 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

8.3.2 Output Voltage Setpoint (FB)

While dependent on switching frequency and load current levels, the LM64460-Q1 is generally capable of providing an output voltage in the range of 1 V to a maximum of slightly less than the input voltage. If the LM64460-Q1 converter is a fixed 3.3-V or 5-V output option, simply connect FB to the output at the point of regulation. With an adjustable output voltage version, define the output voltage setpoint with feedback resistors designated as RFBT and RFBB as shown in Figure 8-1.

Adjustable versions of the converter use a 1-V reference voltage, and the internal error amplifier regulates the FB voltage to be equal to the reference voltage. Use Equation 1 to determine RFBB for a desired output voltage setpoint and a given value of RFBT.

Equation 1. GUID-20211025-SS0I-MMJZ-BDQF-ZC7SWKHJDGLL-low.svg

While RFBT is generally in the range of 10 kΩ to 1 MΩ, use a value of 100 kΩ for improved noise immunity (relative to higher resistances such as 1 MΩ) and reduced current consumption (compared to lower resistance values).