SLVSA67F February   2010  – April 2020 TPS62400-Q1 , TPS62402-Q1 , TPS62404-Q1 , TPS62405-Q1

UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
      2.      TPS62402-Q1 Efficiency versus Output Current, VOUT1 and VOUT2
  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 Timing Requirements
    7. 7.7 Switching Characteristics
    8. 7.8 Typical Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
      1. 9.1.1 Converter 1
      2. 9.1.2 Converter 2
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Enable
      2. 9.3.2 DEF_1 Pin Function
      3. 9.3.3 180° Out-of-Phase Operation
      4. 9.3.4 Short-Circuit Protection
      5. 9.3.5 Thermal Shutdown
      6. 9.3.6 EasyScale Interface: One-Pin Serial Interface for Dynamic Output-Voltage Adjustment
        1. 9.3.6.1 General
        2. 9.3.6.2 Protocol
    4. 9.4 Device Functional Modes
      1. 9.4.1 Power-Save Mode
        1. 9.4.1.1 Dynamic Voltage Positioning
        2. 9.4.1.2 Soft Start
        3. 9.4.1.3 100% Duty-Cycle Low-Dropout Operation
        4. 9.4.1.4 Undervoltage Lockout
      2. 9.4.2 Mode Selection
    5. 9.5 Programming
      1. 9.5.1 Addressable Registers
        1. 9.5.1.1 Bit Decoding
        2. 9.5.1.2 Acknowledge
        3. 9.5.1.3 Mode Selection
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Output Voltage Setting
          1. 10.2.2.1.1 Converter 1 Adjustable Default Output-Voltage Setting: TPS62400-Q1
          2. 10.2.2.1.2 Converter 1 Fixed Default Output-Voltage Setting (TPS62402-Q1, TPS62404-Q1, and TPS62405-Q1)
          3. 10.2.2.1.3 Converter 2 Adjustable Default Output-Voltage Setting (TPS62400-Q1):
          4. 10.2.2.1.4 Converter 2 Fixed Default Output-Voltage Setting
        2. 10.2.2.2 Output Filter Design (Inductor and Output Capacitor)
          1. 10.2.2.2.1 Inductor Selection
          2. 10.2.2.2.2 Output-Capacitor Selection
          3. 10.2.2.2.3 Input Capacitor Selection
      3. 10.2.3 Application Curves
    3. 10.3 System Examples
  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 Support Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報

9.4.1.3 100% Duty-Cycle Low-Dropout Operation

The converters offer a low input-to-output voltage difference while still maintaining operation with the use of the 100% duty-cycle mode. In this mode, the P-channel switch is constantly on. This is particularly useful in battery-powered applications to achieve longest operation time by taking full advantage of the whole battery-voltage range. The minimum input voltage to maintain regulation depends on the load current and output voltage, which one can calculate as:

Equation 3. TPS62400-Q1 TPS62402-Q1 TPS62404-Q1 TPS62405-Q1 q3_vinmin_slvsa67.gif

where

  • IOUTxmax = maximum output current plus inductor ripple current
  • rDS(on)max = maximum P-channel switch rDS(on)
  • RL = dc resistance of the inductor
  • VOUTxmax = nominal output voltage plus maximum output-voltage tolerance

With decreasing load current, the device automatically switches into pulse-skipping operation, in which the power stage operates intermittently based on load demand. Running cycles periodically minimizes the switching losses, and the device runs with a minimum quiescent current, maintaining high efficiency.