SLVSB07A July   2011  – March 2018 TPS61256A

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Smallest Solution Size Application
      2.      Efficiency vs. Load Current
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD 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
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Softstart
    3. 8.3 Undervoltage Lockout
    4. 8.4 Thermal Regulation
    5. 8.5 Thermal Shutdown
    6. 8.6 Functional Block Diagram
    7. 8.7 Feature Description
      1. 8.7.1 Power-Save Mode
      2. 8.7.2 Current Limit Operation
      3. 8.7.3 Enable
      4. 8.7.4 Load Disconnect And Reverse Current Protection
    8. 8.8 Device Functional Modes
      1. 8.8.1 Load Disconnect And Reverse Current Protection
      2. 8.8.2 Softstart
      3. 8.8.3 Undervoltage Lockout
      4. 8.8.4 Thermal Regulation
      5. 8.8.5 Thermal Shutdown
  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 Inductor Selection
          1. 9.2.2.1.1 High-frequency Converter Applications
        2. 9.2.2.2 Output Capacitor
        3. 9.2.2.3 Input Capacitor
        4. 9.2.2.4 Checking Loop Stability
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Thermal Information
  12. 12Package Summary
    1. 12.1 Package Dimensions
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Third-Party Products Disclaimer
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Community Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

9.2.2.1.1 High-frequency Converter Applications

In high-frequency converter applications, the efficiency is essentially affected by the inductor AC resistance (i.e. quality factor) and to a smaller extent by the inductor DCR value. To achieve high efficiency operation, care should be taken in selecting inductors featuring a quality factor above 25 at the switching frequency. Increasing the inductor value produces lower RMS currents, but degrades transient response. For a given physical inductor size, increased inductance usually results in an inductor with lower saturation current.

The total losses of the coil consist of both the losses in the DC resistance, R(DC) , and the following frequency-dependent components:

  • The losses in the core material (magnetic hysteresis loss, especially at high switching frequencies)
  • Additional losses in the conductor from the skin effect (current displacement at high frequencies)
  • Magnetic field losses of the neighboring windings (proximity effect)
  • Radiation losses

The following inductor series from different suppliers have been used with the TPS61256A converters.

Table 2. List Of Inductors

MANUFACTURER(1)SERIESDIMENSIONS (in mm)
MURATA LQH44PN1R0NP0 4.0 x 4.0 x 1.8 max. height
HITACHI METALS KSLI-322512BL1-1R0 3.2 x 2.5 x 1.2 max. height
TOKO DFE322512C-1R0N 3.2 x 2.5 x 1.2 max. height