SNVSA24 October   2014 LMR16006

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
  4. Simplified Schematic
  5. Revision History
  6. Pin Configuration and Functions
  7. Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 Handling Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Switching Characteristics
    7. 7.7 Typical Characteristics
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Fixed Frequency PWM Control
      2. 8.3.2 Bootstrap Voltage (CB)
      3. 8.3.3 Output Voltage Setting
      4. 8.3.4 Enable SHDN and VIN Undervoltage Lockout
      5. 8.3.5 Current Limit
      6. 8.3.6 Overvoltage Transient Protection
      7. 8.3.7 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Continuous Conduction Mode
      2. 8.4.2 ECO Mode
  9. Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Custom Design with WEBENCH Tools
        2. 9.2.2.2 Output Inductor Selection
        3. 9.2.2.3 Output Capacitor Selection
        4. 9.2.2.4 Schottky Diode Selection
        5. 9.2.2.5 Input Capacitor Selection
        6. 9.2.2.6 Bootstrap Capacitor Selection
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Custom Design with WEBENCH Tools
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Related Documentation
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

11 Layout

11.1 Layout Guidelines

Layout is a critical portion of good power supply design. The following guidelines will help users design a PCB with the best power conversion performance, thermal performance, and minimized generation of unwanted EMI.

  1. The feedback network, resistors R1 and R2, should be kept close to the FB pin, and away from the inductor to minimize coupling noise into the feedback pin.
  2. The input bypass capacitor Cin must be placed close to the VIN pin. This will reduce copper trace resistance which effects input voltage ripple of the IC.
  3. The inductor L1 should be placed close to the SW pin to reduce magnetic and electrostatic noise.
  4. The output capacitor, Cout should be placed close to the junction of L1 and the diode D1. The L1, D1, and Cout trace should be as short as possible to reduce conducted and radiated noise and increase overall efficiency.
  5. The ground connection for the diode, Cin, and Cout should be as small as possible and tied to the system ground plane in only one spot (preferably at the Cout ground point) to minimize conducted noise in the system ground plane.
  6. For more detail on switching power supply layout considerations see AN-1149 Layout Guidelines for Switching Power Supplies SNVA021

11.2 Layout Example

LMR16006 layout_example_snvsa24.png Figure 18. Layout