ZHCSHU5A July   2017  – March 2018 TPSM82480

PRODUCTION DATA.  

  1. 1 选项
  2. 2 应用
  3. 3 说明
    1.     Device Images
      1.      典型应用电路原理图 空白
      2.      效率与输出电流间的关系空白空白
  4. 4 修订历史记录
  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 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  Enable / Shutdown (EN)
      2. 7.3.2  Soft Start (SS), Pre-biased Output
      3. 7.3.3  Tracking (TR)
      4. 7.3.4  Output Voltage Select (VSEL)
      5. 7.3.5  Forced PWM (MODE)
      6. 7.3.6  Power Good (PG)
      7. 7.3.7  Thermal Good (TG)
      8. 7.3.8  Active Output Discharge
      9. 7.3.9  Undervoltage Lockout (UVLO)
      10. 7.3.10 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Pulse Width Modulation (PWM) Operation
      2. 7.4.2 Power Save Mode (PSM) Operation
      3. 7.4.3 Minimum Duty Cycle and 100% Mode Operation
      4. 7.4.4 Phase Shifted Operation
      5. 7.4.5 Phase Add/Shed and Current Balancing
      6. 7.4.6 Current Limit and Short Circuit Protection
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Setting the Adjustable Output Voltage
        2. 8.2.2.2 Setting VOUT2 Using the VSEL Feature
        3. 8.2.2.3 Output Capacitor Selection
        4. 8.2.2.4 Input Capacitor Selection
        5. 8.2.2.5 Soft Start Capacitor Selection
        6. 8.2.2.6 Tracking
        7. 8.2.2.7 Thermal Good
      3. 8.2.3 Application Curves
    3. 8.3 System Examples
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11器件和文档支持
    1. 11.1 文档支持
      1. 11.1.1 相关文档
    2. 11.2 接收文档更新通知
    3. 11.3 社区资源
    4. 11.4 商标
    5. 11.5 静电放电警告
    6. 11.6 Glossary
  12. 12机械、封装和可订购信息

封装选项

机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)
订购信息

8.2.2.5 Soft Start Capacitor Selection

The soft start ramp time can be set externally connecting a capacitor between the SS/TR and AGND pins. The capacitor value CSS that is needed to get a specific rising time ΔtSS calculates as:

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Equation 7. TPSM82480 SLVSCL9_eqtss.gif

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Since the device has an internal delay time ΔtDELAY from EN=High to start switching, the overall startup time is longer as shown in Figure 8.

TPSM82480 SLVSCL9_startup.gifFigure 8. Soft Start ΔtSS

If very large output capacitances are used (e.g. >4x47µF), the use of a soft start capacitor is mandatory to avoid current limit foldback during startup (see Current Limit and Short Circuit Protection).