JAJSHJ3D June   2019  – March 2020 TPS62840

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      代表的なアプリケーション
      2.      効率と負荷電流の関係 (VOUT = 1.8V)
  4. 4 改訂履歴
  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 Smart Enable and Shutdown
      2. 8.3.2 Soft Start
      3. 8.3.3 Mode Selection: Power-Save Mode (PFM/PWM) or Forced PWM Operation (FPWM)
      4. 8.3.4 Output Voltage Selection (VSET)
      5. 8.3.5 Undervoltage Lockout UVLO
      6. 8.3.6 Switch Current Limit / Short Circuit Protection
      7. 8.3.7 Output Voltage Discharge
      8. 8.3.8 Thermal Shutdown
      9. 8.3.9 STOP Mode
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power-Save Mode Operation
      2. 8.4.2 Forced PWM Mode Operation
      3. 8.4.3 100% Mode Operation
  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
        2. 9.2.2.2 Output Capacitor Selection
        3. 9.2.2.3 Input Capacitor Selection
      3. 9.2.3 Application Curves
    3. 9.3 System Example
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12デバイスおよびドキュメントのサポート
    1. 12.1 デバイス・サポート
      1. 12.1.1 デベロッパー・ネットワークの製品に関する免責事項
    2. 12.2 サポート・リソース
    3. 12.3 商標
    4. 12.4 静電気放電に関する注意事項
    5. 12.5 Glossary
  13. 13メカニカル、パッケージ、および注文情報

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

8.4.3 100% Mode Operation

In PWM mode, the duty-cycle of a buck converter is given as D = VOUT/VIN. The duty-cycle increases as the input voltage comes closer to the output voltage. Once the input voltage decreases to near 100% duty cycle, the output voltage set point is increased by +30 mV. As the input voltage decreases further, the device enters 100% duty-cycle mode and keeps the high-side MOSFET on continuously. The output (VOUT) is connected to the input (VIN) through the inductor and the internal high-side MOSFET. The minimum input voltage to maintain a given output voltage depends on the load current and is calculated as:

VINmin = VOUT + IOUT × (RDS(on)max + RL)

where

  • IOUT = output current
  • RDS(on)max = maximum P-channel switch RDS(on)
  • RL = DC resistance of the inductor

The TPS6284x contains special circuitry to keep an ultra-low IQ of 120 nA during 100% mode operation.