SNVSCH2 September   2024 LM65645-Q1

ADVANCE INFORMATION  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  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
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Descriptions
      1. 7.3.1 Output Voltage Selection
      2. 7.3.2 EN Pin and Use as VIN UVLO
      3. 7.3.3 Mode Selection
        1. 7.3.3.1 MODE/SYNC Pin Uses for Synchronization
        2. 7.3.3.2 Clock Locking
      4. 7.3.4 Adjustable Switching Frequency
      5. 7.3.5 Dual Random Spread Spectrum (DRSS)
      6. 7.3.6 Internal LDO, VCC UVLO, and BIAS Input
      7. 7.3.7 Bootstrap Voltage (BST Pin)
      8. 7.3.8 Soft Start and Recovery From Dropout
      9. 7.3.9 Safety Features
        1. 7.3.9.1 Power-Good Monitor
        2. 7.3.9.2 Overcurrent and Short-Circuit Protection
        3. 7.3.9.3 Hiccup
        4. 7.3.9.4 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Active Mode
        1. 7.4.2.1 Peak Current Mode Operation
        2. 7.4.2.2 Auto Mode Operation
          1. 7.4.2.2.1 Diode Emulation
        3. 7.4.2.3 FPWM Mode Operation
  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 Custom Design With WEBENCH® Tools
        2. 8.2.2.2 Choosing the Switching Frequency
        3. 8.2.2.3 FB for Adjustable or Fixed Output Voltage Mode
        4. 8.2.2.4 Inductor Selection
        5. 8.2.2.5 Output Capacitor Selection
        6. 8.2.2.6 Input Capacitor Selection
        7. 8.2.2.7 CBOOT
        8. 8.2.2.8 External UVLO
        9. 8.2.2.9 Maximum Ambient Temperature
    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 Third-Party Products Disclaimer
      2. 9.1.2 Development Support
        1. 9.1.2.1 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
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information
    1. 11.1 Tape and Reel Information

Package Options

Mechanical Data (Package|Pins)
  • RZT|20
Thermal pad, mechanical data (Package|Pins)
Orderable Information

1 Features

  • AEC-Q100 qualified for automotive applications:
    • Temperature grade 1: –40°C to +125°C, TA
  • Wide input voltage range: 3V to 65V
  • Designed for low EMI requirements
    • Facilitates CISPR 25 class 5 compliance
    • Mode pin configurable ±5% or ±10% dual-random spread spectrum reducing peak emissions
    • Enhanced HotRod™ QFN package with symmetrical pinout
    • Switching frequency from 300kHz to 2.2MHz
    • Pin-configurable 400kHz and 2.2MHz
    • Pin-configurable AUTO or FPWM operation
  • Low minimum on time: 40ns (maximum)
    • Enables 36V to 3.3V conversion at 2.2MHz
  • High-efficiency power conversion at all loads
    • > 94% peak efficiency at 24VIN, 5VOUT, 400kHz
    • 2.5µA PFM no-load input current
  • High power density
    • Internal compensation, current limit, and TSD
    • 3.6mm × 2.6mm, wettable flank, 20-pin package
    • ϴJA = 25.5°C/W (LM65645-Q1EVM)
  • Create a custom design using the LM656x5-Q1 with the WEBENCH® Power Designer