SNVS135E September   1999  – December 2014 LM2660

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 Handling Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. 7 Parameter Measurement Information
    1. 7.1 Test Circuits
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Changing Oscillator Frequency
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Voltage Inverter
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Capacitor Selection
          2. 9.2.1.2.2 Paralleling Devices
          3. 9.2.1.2.3 Cascading Devices
          4. 9.2.1.2.4 Regulating VOUT
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Positive Voltage Doubler
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 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 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Trademarks
    3. 12.3 Electrostatic Discharge Caution
    4. 12.4 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

11 Layout

11.1 Layout Guidelines

The high switching frequency and large switching currents of the LM2660 make the choice of layout important. The following steps should be used as a reference to ensure the device is stable and maintains proper LED current regulation across its intended operating voltage and current range:

  • Place CIN on the top layer (same layer as the LM2660) and as close to the device as possible. Connecting the input capacitor through short, wide traces to both the V+ and GND pins reduces the inductive voltage spikes that occur during switching which can corrupt the V+ line.
  • Place COUT on the top layer (same layer as the LM2660) and as close as possible to the OUT and GND pin. The returns for both CIN and COUT should come together at one point, as close to the GND pin as possible. Connecting COUT through short, wide traces reduce the series inductance on the OUT and GND pins that can corrupt the VOUT and GND lines and cause excessive noise in the device and surrounding circuitry.
  • Place C1 on the top layer (same layer as the LM2660) and as close to the device as possible. Connect the flying capacitor through short, wide traces to both the CAP+ and CAP– pins.

11.2 Layout Example

layout.gifFigure 25. LM2660 Layout Example