SLVSB71E February   2012  – September 2016 TLV62150 , TLV62150A

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application Schematic
      2.      Efficiency vs Output Current
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin 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 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 Enable / Shutdown (EN)
      2. 8.3.2 Soft Start / Tracking (SS/TR)
      3. 8.3.3 Power Good (PG)
      4. 8.3.4 Pin-Selectable Output Voltage (DEF)
      5. 8.3.5 Frequency Selection (FSW)
      6. 8.3.6 Undervoltage Lockout (UVLO)
      7. 8.3.7 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Pulse Width Modulation (PWM) Operation
      2. 8.4.2 Power Save Mode Operation
      3. 8.4.3 100% Duty-Cycle Operation
      4. 8.4.4 Current Limit and Short Circuit Protection
  9. 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 Programming the Output Voltage
        2. 9.2.2.2 External Component Selection
          1. 9.2.2.2.1 Inductor Selection
          2. 9.2.2.2.2 Capacitor Selection
            1. 9.2.2.2.2.1 Output Capacitor
            2. 9.2.2.2.2.2 Input Capacitor
            3. 9.2.2.2.2.3 Soft-Start Capacitor
        3. 9.2.2.3 Tracking Function
        4. 9.2.2.4 Output Filter and Loop Stability
      3. 9.2.3 Application Curves
    3. 9.3 System Examples
      1. 9.3.1 LED Power Supply
      2. 9.3.2 Active Output Discharge
      3. 9.3.3 Inverting Power Supply
      4. 9.3.4 Various Output Voltages
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Thermal Considerations
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Related Links
    3. 12.3 Documentation Support
      1. 12.3.1 Related Documentation
    4. 12.4 Receiving Notification of Documentation Updates
    5. 12.5 Community Resources
    6. 12.6 Trademarks
    7. 12.7 Electrostatic Discharge Caution
    8. 12.8 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

9.2.2.4 Output Filter and Loop Stability

The TLV62150 is internally compensated to be stable with L-C filter combinations corresponding to a corner frequency to be calculated with Equation 12:

Equation 12. TLV62150 TLV62150A SLVSAG7_eqLCfilt.gif

Proven nominal values for inductance and ceramic capacitance are given in Table 4 and are recommended for use. Different values may work, but care has to be taken on the loop stability which will be affected. More information including a detailed L-C stability matrix can be found in SLVA463.

The TLV62150 includes an internal 25 pF feedforward capacitor, connected between the VOS and FB pins. This capacitor impacts the frequency behavior and sets a pole and zero in the control loop with the resistors of the feedback divider, per equation Equation 13 and Equation 14:

spacing

Equation 13. TLV62150 TLV62150A SLVSAG7_eqCffzero.gif

spacing

Equation 14. TLV62150 TLV62150A SLVSAG7_eqCffpole.gif

spacing

Though the TLV62150 is stable without the pole and zero being in a particular location, adjusting their location to the specific needs of the application can provide better performance in Power Save mode and/or improved transient response. An external feedforward capacitor can also be added. A more detailed discussion on the optimization for stability versus transient response can be found in SLVA289 and SLVA466.