ZHCSHS4 March   2018 TPS62243-Q1 , TPS62244-Q1

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     Device Images
      1.      典型应用原理图
      2.      效率与输出电流间的关系
  4. 4 修订历史记录
  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 Undervoltage Lockout
      2. 8.3.2 Enable
      3. 8.3.3 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Soft Start
      2. 8.4.2 Power Save Mode
        1. 8.4.2.1 100% Duty Cycle Low Dropout Operation
      3. 8.4.3 Short-Circuit Protection
  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 Output Filter Design (Inductor and Output Capacitor)
          1. 9.2.2.1.1 Inductor Selection
          2. 9.2.2.1.2 Output Capacitor Selection
          3. 9.2.2.1.3 Input Capacitor Selection
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12器件和文档支持
    1. 12.1 第三方产品免责声明
    2. 12.2 接收文档更新通知
    3. 12.3 社区资源
    4. 12.4 商标
    5. 12.5 静电放电警告
    6. 12.6 Glossary
  13. 13机械、封装和可订购信息
    1. 13.1 Package Option Addendum
      1. 13.1.1 Packaging Information
      2. 13.1.2 Tape and Reel Information

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

9.2.2.1.3 Input Capacitor Selection

The buck converter has a natural pulsating input current; therefore, a low-ESR input capacitor is required for best input voltage filtering and minimizing the interference with other circuits caused by high-input voltage spikes. For most applications, a 4.7-μF to 10-μF ceramic capacitor is recommended (Table 4). Because ceramic capacitors lose up to 80% of their initial capacitance at 5 V, TI recommends using a 10-μF input capacitor for input voltages greater than 4.5 V. The input capacitor can be increased without any limit for better input voltage filtering.

Take care when using only small ceramic input capacitors. When a ceramic capacitor is used at the input, and the power is being supplied through long wires, such as from a wall adapter, a load step at the output, or VIN step on the input, can induce ringing at the VIN pin. The ringing can couple to the output and be mistaken as loop instability, or could even damage the part by exceeding the maximum ratings.

Table 4. List of Capacitors

CAPACITANCE (µF) DIMENSIONS (mm) PART NUMBER MANUFACTURER(1)
4.7 0603: 1.6 × 0.8 × 0.8 GRM188R60J475K Murata
10 0603: 1.6 × 0.8 × 0.8 GRM188R60J106M69D Murata