SLVS644E February   2006  – December 2014 TPS61080 , TPS61081


  1. Features
  2. Applications
  3. Description
  4. 5-V To 12-V, 250-mA Step-Up DC-DC Converter
  5. Revision History
  6. Device Comparison Table
  7. Pin Configuration and Functions
  8. Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Typical Characteristics
  9. Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Start Up
      2. 9.3.2 Overcurrent and Short Circuit Protection
      3. 9.3.3 Overvoltage Protection
      4. 9.3.4 Undervoltage Lockout (UVLO)
      5. 9.3.5 Thermal Shutdown
    4. 9.4 Device Functional Modes
      1. 9.4.1 Enable
      2. 9.4.2 Frequency Selection
      3. 9.4.3 Maximum and Minimum Output Current
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Program Output Voltage
      2. 10.1.2 Feed Forward Capacitor
      3. 10.1.3 Soft Start Capacitor
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. Inductor Selection
        2. Input And Output Capacitor Selection
      3. 10.2.3 Application Curves
    3. 10.3 System Examples
      1. 10.3.1 Torch Light and Flash Light
      2. 10.3.2 24Vout Output Converter
      3. 10.3.3 30 WLEDs Driver in Media Factor Form Display
        1. ±15 V Dual Output Converter
        2. Step-Up DC-DC Converter with Output Doubler
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Third-Party Products Disclaimer
    2. 13.2 Related Links
    3. 13.3 Trademarks
    4. 13.4 Electrostatic Discharge Caution
    5. 13.5 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

12 Layout

12.1 Layout Guidelines

As for all switching power supplies, the layout is an important step in the design, especially for high current and high switching frequencies. If the layout is not carefully done, the regulator could show stability problems as well as EMI problems. Therefore, use wide and short traces for high current paths and for power ground tracks. Input capacitor needs not only to be close to the VIN, but also close to the GND pin to reduce the voltage ripple seen by the IC. The L and SW pins are conveniently located on the edge of the IC, therefore the inductor can be placed close to the IC. The output capacitor needs to be placed near the load to minimize ripple and maximize transient performance.

To minimize the effects of ground noise, use a common node for all power grounds that are connected to the PGND pin; and, a different one for signal ground tying to the GND pin. Connect two ground nodes together at the load if possible. This allows the GND pin to be close to the output ground for good DC regulation. Any voltage difference between these two nodes would be gained up by feedback divider on the output. It is also beneficial to have the ground of the output capacitor close to PGND because there is a large current between them. To lay out signal ground, it is recommended to use short traces separated from power ground traces.

12.2 Layout Example