JAJSEQ9E November   2013  – December 2017 TPS56520 , TPS56720 , TPS56920 , TPS56C20

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回路
  4. 4 改訂履歴
  5. 5 概要(続き)
  6. 6 List of Devices
  7. 7 Pin Configuration and Functions
    1.     Pin Functions
    2.     Pin Functions
  8. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Timing Requirements
    7. 8.7 Switching Characteristics
    8. 8.8 Typical Characteristics
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 PWM Operation
      2. 9.3.2 PWM Frequency and Adaptive On-Time Control
      3. 9.3.3 VIN and Power VIN Terminals (VIN and PVIN)
      4. 9.3.4 Auto-Skip Eco-mode™ Control
      5. 9.3.5 Soft Start and Pre-Biased Soft Start
      6. 9.3.6 Power Good
      7. 9.3.7 Overcurrent Protection
      8. 9.3.8 UVLO Protection
    4. 9.4 Device Functional Modes
      1. 9.4.1 Operation at Light Loads
    5. 9.5 Programming
      1. 9.5.1 I2C Interface
      2. 9.5.2 I2C Protocol
      3. 9.5.3 I2C Chip Address Byte
    6. 9.6 Register Maps
      1. 9.6.1 I2C Register Address Byte
      2. 9.6.2 Output Voltage Registers
      3. 9.6.3 CheckSum Bit (VOUT Register Only)
      4. 9.6.4 Control Registers
      5. 9.6.5 Latchoff
  10. 10Applications and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 TPS56520, TPS56720 and TPS56920, 5-A, 7-A, and 9-A Converter
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
          1. 10.2.1.2.1 Output Voltage Resistors Selection
            1. 10.2.1.2.1.1 Output Filter Selection
          2. 10.2.1.2.2 Input Capacitor Selection
          3. 10.2.1.2.3 Bootstrap Capacitor Selection
          4. 10.2.1.2.4 VREG5 Capacitor Selection
      2. 10.2.2 TPS56520, TPS56720 and TPS56920 Application Performance Curves
      3. 10.2.3 TPS56C20 12-A Converter
        1. 10.2.3.1 Design Requirements
        2. 10.2.3.2 Design Procedure
        3. 10.2.3.3 TPS56C20 Application Performance Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13デバイスおよびドキュメントのサポート
    1. 13.1 デバイス・サポート
      1. 13.1.1 開発サポート
    2. 13.2 ドキュメントのサポート
      1. 13.2.1 関連資料
    3. 13.3 関連リンク
    4. 13.4 商標
    5. 13.5 静電気放電に関する注意事項
    6. 13.6 Glossary
  14. 14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

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）
  • PWP|20
サーマルパッド・メカニカル・データ
発注情報

9.3.5 Soft Start and Pre-Biased Soft Start

The soft start function is adjustable. When the EN terminal becomes high, 6-µA current begins charging the capacitor which is connected from the SS terminal to GND. Smooth control of the output voltage is maintained during start up. The equation for the slow start time is shown in Equation 1. VFB voltage is 0.6 V and SS terminal source current is 6µA.

Equation 1. TPS56C20 TPS56920 TPS56720 TPS56520 EQ2_tss_slvscb6.gif

The TPS56X20 contains a unique circuit to prevent current from being pulled from the output during startup if the output is pre-biased. When the soft-start commands a voltage higher than the pre-bias level (internal soft start becomes greater than internal feedback voltage, VFB), the controller slowly activates synchronous rectification by starting the first low side FET gate driver pulses with a narrow on-time. It then increments that on-time on a cycle-by-cycle basis until it coincides with the time dictated by (1-D), where D is the duty cycle of the converter. This scheme prevents the initial sinking of the pre-biased output, and ensures that the output voltage (VOUT) starts and ramps up smoothly into regulation from pre-biased startup to normal mode operation. When pre-biased conditions exist, it is recommended to disable the device by pulling the EN terminal to ground.