SNVSA47D February   2016  – December 2022 LM5165

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  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 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  10. 10Mechanical, Packaging, and Orderable Information

8.2.1.1 Design Requirements

The target full-load efficiency is 91% based on a nominal input voltage of 12 V and an output voltage of 5 V. The required input voltage range is 5 V to 65 V. The LM5165X is chosen to deliver a fixed 5-V output voltage. The switching frequency is set by resistor RRT at 220 kHz. The output voltage soft-start time is 6 ms. The required components are listed in Table 8-1.

Table 8-1 List of Components for Design 1
REF DESQTYSPECIFICATIONVENDORPART NUMBER
CIN11 µF, 100 V, X7R, 1206 ceramicTDKC3216X7R2A105K160AA
COUT122 µF, 10 V, X7R, 1206 ceramicMurataGRM31CR71A226KE15L
LF1220 µH ±20%, 0.29 A, 0.92 Ω typ DCR, 5.8 x 5.8 x 2.8 mmWürth ElectronikWE-TPC 5828 744053221
220 µH ±30%, 0.3 A, 1.25 Ω max DCR, 5.8 x 5.8 x 3.0 mmBournsSRR5028-221Y
RESR11.5 Ω, 5%, 0402StdStd
RRT1133 kΩ, 1%, 0402StdStd
CSS147 nF, 10 V, X7R, 0402 ceramicStdStd
U11LM5165X Synchronous Buck Converter, VSON-10, 5V FixedTILM5165XDRCR