JAJSKQ3D February   2016  – December 2022 LM5165

PRODUCTION DATA  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 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 Switching Characteristics
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Integrated Power MOSFETs
      2. 7.3.2  Selectable PFM or COT Mode Converter Operation
      3. 7.3.3  COT Mode Light-Load Operation
      4. 7.3.4  Low Dropout Operation and 100% Duty Cycle Mode
      5. 7.3.5  Adjustable Output Voltage (FB)
      6. 7.3.6  Adjustable Current Limit
      7. 7.3.7  Precision Enable (EN) and Hysteresis (HYS)
      8. 7.3.8  Power Good (PGOOD)
      9. 7.3.9  Configurable Soft Start (SS)
      10. 7.3.10 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Standby Mode
      3. 7.4.3 Active Mode in COT
      4. 7.4.4 Active Mode in PFM
      5. 7.4.5 Sleep Mode in PFM
  8. 8 Applications and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Design 1: Wide VIN, Low IQ COT Converter Rated at 5 V, 150 mA
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Custom Design With WEBENCH® Tools
          2. 8.2.1.2.2 Switching Frequency – RT
          3. 8.2.1.2.3 Filter Inductor – LF
          4. 8.2.1.2.4 Output Capacitors – COUT
          5. 8.2.1.2.5 Series Ripple Resistor – RESR
          6. 8.2.1.2.6 Input Capacitor – CIN
          7. 8.2.1.2.7 Soft-Start Capacitor – CSS
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Design 2: Small Solution Size PFM Converter Rated at 3.3 V, 50 mA
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
          1. 8.2.2.2.1 Peak Current Limit Setting – RILIM
          2. 8.2.2.2.2 Switching Frequency – LF
          3. 8.2.2.2.3 Output Capacitor – COUT
          4. 8.2.2.2.4 Input Capacitor – CIN
        3. 8.2.2.3 Application Curves
      3. 8.2.3 Design 3: High Density 12-V, 75-mA PFM Converter
        1. 8.2.3.1 Design Requirements
        2. 8.2.3.2 Detailed Design Procedure
          1. 8.2.3.2.1 Peak Current Limit Setting – RILIM
          2. 8.2.3.2.2 Switching Frequency – LF
          3. 8.2.3.2.3 Input and Output Capacitors – CIN, COUT
          4. 8.2.3.2.4 Feedback Resistors – RFB1, RFB2
          5. 8.2.3.2.5 Undervoltage Lockout Setpoint – RUV1, RUV2, RHYS
          6. 8.2.3.2.6 Soft Start – CSS
        3. 8.2.3.3 Application Curves
      4. 8.2.4 Design 4: 3.3-V, 150-mA COT Converter With High Efficiency
        1. 8.2.4.1 Design Requirements
        2. 8.2.4.2 Application Curves
      5. 8.2.5 Design 5: 15-V, 150-mA, 600-kHz COT Converter
        1. 8.2.5.1 Design Requirements
        2. 8.2.5.2 Detailed Design Procedure
          1. 8.2.5.2.1 COT Output Ripple Voltage Reduction
        3. 8.2.5.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
        1. 8.4.1.1 Compact PCB Layout for EMI Reduction
        2. 8.4.1.2 Feedback Resistor Layout
      2. 8.4.2 Layout Example
  9. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Third-Party Products Disclaimer
      2. 9.1.2 Development Support
      3. 9.1.3 Custom Design With WEBENCH® Tools
    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
  10. 10Mechanical, 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
8.2.2.2.2 Switching Frequency – LF

Tie RT to GND to select PFM mode of operation. The inductor, input voltage, output voltage, and peak current determine the pulse switching frequency of a PFM-configured LM5165. For a given input voltage, output voltage and peak current, the inductance of LF sets the switching frequency when the output is in regulation. Use Equation 19 to select an inductance of 47 µH based on the target PFM converter switching frequency of 350 kHz at 12-V input.

Equation 19. GUID-6B2B288A-3E47-4372-9D1F-D71EDEECB203-low.gif

IPK(PFM) in this example is the peak current limit setting of 120 mA plus an additional 10% margin added to include the effect of the 100-ns peak current comparator delay. An additional constraint on the inductance is the 180-ns minimum on-time of the high-side MOSFET. Therefore, to keep the inductor current well controlled, choose an inductance that is larger than LF(min) using Equation 20 where VIN(max) is the maximum input supply voltage for the application, tON(min) is 180 ns, and IL(max) is the maximum allowed peak inductor current.

Equation 20. GUID-66E0270C-1639-49C8-9F78-FF41BF34902D-low.gif

Choose an inductor with saturation current rating above the peak current limit setting, and allow for derating of the saturation current at the highest expected operating temperature.