JAJSKO7F October   2020  – January 2024 LMR43610-Q1 , LMR43620-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 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 System Characteristics
    7. 6.7 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Enable, Start-Up, and Shutdown
      2. 7.3.2  External CLK SYNC (with MODE/SYNC)
        1. 7.3.2.1 Pulse-Dependent MODE/SYNC Pin Control
      3. 7.3.3  Adjustable Switching Frequency (with RT)
      4. 7.3.4  Power-Good Output Operation
      5. 7.3.5  Internal LDO, VCC, and VOUT/FB Input
      6. 7.3.6  Bootstrap Voltage and VBOOT-UVLO (BOOT Terminal)
      7. 7.3.7  Output Voltage Selection
      8. 7.3.8  Spread Spectrum
      9. 7.3.9  Soft Start and Recovery from Dropout
        1. 7.3.9.1 Recovery from Dropout
      10. 7.3.10 Current Limit and Short Circuit
      11. 7.3.11 Thermal Shutdown
      12. 7.3.12 Input Supply Current
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Standby Mode
      3. 7.4.3 Active Mode
        1. 7.4.3.1 CCM Mode
        2. 7.4.3.2 Auto Mode – Light-Load Operation
          1. 7.4.3.2.1 Diode Emulation
          2. 7.4.3.2.2 Frequency Reduction
        3. 7.4.3.3 FPWM Mode – Light-Load Operation
        4. 7.4.3.4 Minimum On-Time (High Input Voltage) Operation
        5. 7.4.3.5 Dropout
  9. 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  Choosing the Switching Frequency
        2. 8.2.2.2  Setting the Output Voltage
          1. 8.2.2.2.1 FB for Adjustable Output
        3. 8.2.2.3  Inductor Selection
        4. 8.2.2.4  Output Capacitor Selection
        5. 8.2.2.5  Input Capacitor Selection
        6. 8.2.2.6  CBOOT
        7. 8.2.2.7  VCC
        8. 8.2.2.8  CFF Selection
        9. 8.2.2.9  External UVLO
        10. 8.2.2.10 Maximum Ambient Temperature
      3. 8.2.3 Application Curves
    3. 8.3 Best Design Practices
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
        1. 8.5.1.1 Ground and Thermal Considerations
      2. 8.5.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 サード・パーティ製品に関する免責事項
      2. 9.1.2 Device Nomenclature
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 ドキュメントの更新通知を受け取る方法
    4. 9.4 サポート・リソース
    5. 9.5 Trademarks
    6. 9.6 静電気放電に関する注意事項
    7. 9.7 用語集
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information
    1. 11.1 Mechanical Data

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

7.3.2 External CLK SYNC (with MODE/SYNC)

It is often desirable to synchronize the operation of multiple regulators in a single system, resulting in a well-defined system level performance. The select variants in the LMR436x0-Q1 with the MODE/SYNC pin allow the power designer to synchronize the device to a common external clock. The LMR436x0-Q1 implements an in-phase locking scheme, where the rising edge of the clock signal, provided to the MODE/SYNC pin of the LMR436x0-Q1, corresponds to the turning on of the high-side device. The external clock synchronization is implemented using a phase locked loop (PLL), eliminating any large glitches. The external clock fed into the LMR436x0-Q1 replaces the internal free-running clock, but does not affect any frequency foldback operation. Output voltage continues to be well-regulated. The device remains in FPWM mode and operates in CCM for light loads when synchronization input is provided.

The MODE/SYNC input pin in the LMR436x0-Q1 can operate in one of three selectable modes:

  • Auto mode: Pulse frequency modulation (PFM) operation is enabled during light load and diode emulation prevents reverse current through the inductor. See Section 7.4.3.2 for more details.
  • FPWM mode: In FPWM mode, diode emulation is disabled, allowing current to flow backwards through the inductor. This allows operation at full frequency even without load current. See Section 7.4.3.3 for more details.
  • SYNC mode: The internal clock locks to an external signal applied to the MODE/SYNC pin. As long as output voltage can be regulated at full frequency and is not limited by minimum off time or minimum on time, clock frequency is matched to the frequency of the signal applied to the MODE/SYNC pin. While the device is in SYNC mode, it operates as though in FPWM mode: diode emulation is disabled, allowing the frequency applied to the MODE/SYNC pin to be matched without a load.