SNAS660D June   2015  – May 2021 LM53600-Q1 , LM53601-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison
  6. 6 Pin Configuration and Functions
  7. 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 System Characteristics
    7. 7.7 Timing Requirements
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Control Scheme
      2. 8.3.2 Soft-Start Function
      3. 8.3.3 Current Limit
      4. 8.3.4 Hiccup Mode
      5. 8.3.5 RESET Function
      6. 8.3.6 Forced PWM Operation
      7. 8.3.7 Auto Mode Operation and IQ_VIN
      8. 8.3.8 SYNC Operation
      9. 8.3.9 Spread Spectrum
    4. 8.4 Device Functional Modes
      1. 8.4.1 Shutdown
      2. 8.4.2 FPWM Operation
      3. 8.4.3 Auto Mode Operation
  9. 9 Applications and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Off-Battery 5-V, 1-A Output Automotive Converter with Spread Spectrum
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Inductor Selection
          2. 9.2.1.2.2 Output Capacitor Selection
          3. 9.2.1.2.3 Input Capacitor Selection
          4. 9.2.1.2.4 FB Voltage Divider for Adjustable Versions
          5. 9.2.1.2.5 RPU - RESET Pull Up Resistor
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Off-Battery 3.3 V, 1 A Output Automotive Converter with Spread Spectrum
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Design Procedure
        3. 9.2.2.3 Application Curves
    3. 9.3 Do's and Don't's
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Ground and Thermal Plane Considerations
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

11.1 Layout Guidelines

The following list is in order of importance starting with the most important item:-

  • Place high frequency input bypass capacitor, Cinhf, as close to the LM53600-Q1 and LM53601-Q1 devices as possible.
  • Connect AGND and GND to the DAP immediately adjacent to the LM53600-Q1 and LM53601-Q1 devices.
  • Do not interrupt the ground plain under the loop containing the VIN and GND pins and Cinhf of the LM53600-Q1 and LM53601-Q1 devices.
  • The boot capacitor, CBOOT, should be close to the LM53601-Q1 and the loop from the SW pin, through the boot capacitor and into the BOOT pin should be kept as small as possible.
  • Keep the SW node as small as possible. It should be wide enough to carry the converter’s full current without significant drop.
  • 4.7 µF of bypassing should be close to the input of the LM53600-Q1 and LM53601-Q1 devices.
  • Place CVCC, the VCC pin’s bypass, and CBIAS, the bypass for FB for fixed voltage devices and BIAS for adjustable devices as close to the LM53600-Q1 and LM53601-Q1 devices as possible.
  • The first output the trace from the output inductor to the output node should run by an output capacitor before joining the rest of the output node.
  • Keep 10 µF close to the output (output inductor and GND) of the LM53600-Q1 and LM53601-Q1 devices.
  • Clear the layer beneath the SW node.
Table 11-1 PCB Layout Resources
TITLELINK
AN-1149 Layout Guidelines for Switching Power SuppliesSNVA021
AN-1229 Simple Switcher PCB Layout GuidelinesSNVA054
Constructing Your Power Supply- Layout ConsiderationsSLUP230
SNVA721 Low Radiated EMI Layout Made SIMPLE with LM4360x and LM4600xSNVA721
GUID-88F98522-5CEC-4F38-95B8-69538AF9BC90-low.gifFigure 11-1 Current Loops with Fast Transients