JAJSDP3C March   2016  – June 2018 LMZ34202

PRODUCTION DATA.  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
    1.     Device Images
      1.      アプリケーション概略図
      2.      効率と出力電流との関係
  4. 4 改訂履歴
  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 Switching Characteristics
    7. 6.7 Typical Characteristics
    8. 6.8 Typical Characteristics (Thermal Derating)
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Adjusting the Output Voltage
      2. 7.3.2  Switching Frequency (RT)
      3. 7.3.3  Recommended Operating Range
      4. 7.3.4  Synchronization (CLK)
      5. 7.3.5  Output Capacitor Selection
      6. 7.3.6  VERSA-COMP Pin Configurations
      7. 7.3.7  Input Capacitor Selection
      8. 7.3.8  Output On/Off Inhibit (INH/UVLO)
      9. 7.3.9  Under Voltage Lockout (UVLO)
      10. 7.3.10 Remote Sense
      11. 7.3.11 VBSEL
      12. 7.3.12 Soft-Start (SS/TR)
      13. 7.3.13 Power Good (PWRGD) and Pull-up (PWRGD_PU)
      14. 7.3.14 Overcurrent Protection
      15. 7.3.15 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Active Mode
      2. 7.4.2 Light Load Operation
      3. 7.4.3 Shutdown Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Minimum External Component Application
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Custom Design With WEBENCH® Tools
          2. 8.2.1.2.2 Output Voltage Set-Point
          3. 8.2.1.2.3 RT and RTSEL
          4. 8.2.1.2.4 VERSA-COMP
          5. 8.2.1.2.5 VBSEL
          6. 8.2.1.2.6 Input Capacitors
          7. 8.2.1.2.7 Output Capacitors
        3. 8.2.1.3 Application Curves
      2. 8.2.2 INH Control Application
        1. 8.2.2.1 Design Requirements
      3. 8.2.3 Detailed Design Procedure
        1. 8.2.3.1 Switching Frequency
        2. 8.2.3.2 Power Good
        3. 8.2.3.3 Inhibit Control
        4. 8.2.3.4 VERSA-COMP
        5. 8.2.3.5 VBSEL
        6. 8.2.3.6 Soft-Start Capacitors
        7. 8.2.3.7 Input Capacitors
        8. 8.2.3.8 Output Capacitors
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 EMI
  11. 11デバイスおよびドキュメントのサポート
    1. 11.1 デバイス・サポート
      1. 11.1.1 開発サポート
        1. 11.1.1.1 WEBENCH®ツールによるカスタム設計
      2. 11.1.2 デベロッパー・ネットワークの製品に関する免責事項
    2. 11.2 ドキュメントの更新通知を受け取る方法
    3. 11.3 コミュニティ・リソース
    4. 11.4 商標
    5. 11.5 静電気放電に関する注意事項
    6. 11.6 Glossary
  12. 12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

7.3.12 Soft-Start (SS/TR)

Leaving SS/TR pin open enables the internal slow start time interval of approximately 4.1 ms. Adding additional capacitance between the SS pin and AGND increases the slow start time. Increasing the slow start time will reduce inrush current seen by the input source and reduce the current seen by the device when charging the output capacitors. To avoid the activation of current limit and ensure proper start-up, the SS capacitor may need to be increased when operating near the maximum output capacitance limit.

See Table 11 below for SS capacitor values and timing interval.

Table 11. Soft-Start Capacitor Values and Soft-Start Time

CSS (nF) open 15 22 33 47
SS Time (ms) 4.1 7 10 15 20