ZHCSJY4B July   2008  – June 2019 TPS5450-Q1

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     Device Images
      1.      简化原理图和效率曲线
  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 Recommended Operating Conditions
    3. 6.3 Thermal Information
    4. 6.4 Dissipation Ratings
    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  Oscillator Frequency
      2. 7.3.2  Voltage Reference
      3. 7.3.3  Enable (ENA) and Internal Slow Start
      4. 7.3.4  Undervoltage Lockout (UVLO)
      5. 7.3.5  Output Feedback (VSENSE) and Internal Compensation
      6. 7.3.6  Voltage Feedforward
      7. 7.3.7  Pulse-Width-Modulation (PWM) Control
      8. 7.3.8  Overcurrent Limiting
      9. 7.3.9  Overvoltage Protection
      10. 7.3.10 Thermal Shutdown
  8. 8 Application Information
    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  Custom Design With WEBENCH® Tools
        2. 8.2.2.2  Boost Capacitor (BOOT)
        3. 8.2.2.3  Switching Frequency
        4. 8.2.2.4  Input Capacitors
        5. 8.2.2.5  Output Filter Components
          1. 8.2.2.5.1 Inductor Selection
          2. 8.2.2.5.2 Capacitor Selection
        6. 8.2.2.6  Output Voltage Setpoint
        7. 8.2.2.7  Boot Capacitor
        8. 8.2.2.8  Catch Diode
        9. 8.2.2.9  Output Voltage Limitations
        10. 8.2.2.10 Internal Compensation Network
      3. 8.2.3 Application Curves
  9. 9 Layout
    1. 9.1 Layout Guidelines
    2. 9.2 Layout Examples
    3. 9.3 Thermal Calculations
  10. 10器件和文档支持
    1. 10.1 器件支持
      1. 10.1.1 第三方产品免责声明
    2. 10.2 开发支持
      1. 10.2.1 使用 WEBENCH® 工具创建定制设计
    3. 10.3 接收文档更新通知
    4. 10.4 社区资源
    5. 10.5 商标
    6. 10.6 静电放电警告
    7. 10.7 Glossary
  11. 11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

7.3.3 Enable (ENA) and Internal Slow Start

The ENA pin provides electrical on/off control of the regulator. Once the ENA pin voltage exceeds the threshold voltage, the regulator starts operation and the internal slow start begins to ramp. If the ENA pin voltage is pulled below the threshold voltage, the regulator stops switching and the internal slow start resets. Connecting the pin to ground or to any voltage less than 0.5 V disables the regulator and activates the shutdown mode. The quiescent current of the TPS5450-Q1 in shutdown mode is 18 μA (typical).

The ENA pin has an internal pullup current source, allowing the user to float the ENA pin. If an application requires controlling the ENA pin, use open drain or open collector output logic to interface with the pin. To limit the start-up inrush current, an internal slow-start circuit is used to ramp up the reference voltage from 0  V to its final value, linearly. The internal slow start time is 8 ms (typical).