JAJSLU8C February   2019  – April 2021 TPS51396A

PRODUCTION DATA  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
  4. 4 Revision History
  5. 5 Pin Configuration and 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 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 PWM Operation and D-CAP3 Control
      2. 7.3.2 Soft Start
      3. 7.3.3 Large Duty Operation
      4. 7.3.4 Power Good
      5. 7.3.5 Over Current Protection and Undervoltage Protection
      6. 7.3.6 Over Voltage Protection
      7. 7.3.7 UVLO Protection
      8. 7.3.8 Output Voltage Discharge
      9. 7.3.9 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Light Load Operation
      2. 7.4.2 Advanced Eco-mode Control
      3. 7.4.3 Out of Audio Mode
      4. 7.4.4 Mode Selection
      5. 7.4.5 Standby Operation
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 1V Output Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 External Component Selection
          1. 8.2.2.1.1 Output Voltage Set Point
          2. 8.2.2.1.2 Inductor Selection
          3. 8.2.2.1.3 Output Capacitor Selection
          4. 8.2.2.1.4 Input Capacitor Selection
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 サポート・リソース
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

パッケージ・オプション

デバイスごとのパッケージ図は、PDF版データシートをご参照ください。

メカニカル・データ（パッケージ｜ピン）
  • RJE|20
サーマルパッド・メカニカル・データ
発注情報

7.4.2 Advanced Eco-mode Control

The advanced Eco-mode™ control scheme to maintain high light load efficiency. As the output current decreases from heavy load conditions, the inductor current is also reduced and eventually comes to a point where the rippled valley touches zero level, which is the boundary between continuous conduction and discontinuous conduction modes. The rectifying MOSFET is turned off when the zero inductor current is detected. As the load current further decreases, the converter runs into discontinuous conduction mode. The on-time is kept almost the same as it was in the continuous conduction mode so that it takes longer time to discharge the output capacitor with smaller load current to the level of the reference voltage. This makes the switching frequency lower, proportional to the load current, and keeps the light load efficiency high. The light load current where the transition to Eco-mode™ operation happens ( IOUT(LL) ) can be calculated from Equation 3.

Equation 3. GUID-9C236BCB-A2AC-4256-B21C-121D3C87D83C-low.gif

After identifying the application requirements, design the output inductance (LOUT) so that the inductor peak-to-peak ripple current is approximately between 20% and 30% of the IOUT(max) (peak current in the application). It is also important to size the inductor properly so that the valley current does not hit the negative low-side current limit.