ZHCSL73B October   2016  – June 2021 TPS54388C-Q1

PRODUCTION DATA  

  1. 特性
  2. 应用
  3. 说明
  4. Revision History
  5. Pin Configuration and Functions
  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. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Fixed-Frequency PWM Control
      2. 7.3.2 Slope Compensation and Output Current
      3. 7.3.3 Bootstrap Voltage (BOOT) and Low-Dropout Operation
      4. 7.3.4 Error Amplifier
      5. 7.3.5 Voltage Reference
    4. 7.4 Device Functional Modes
      1. 7.4.1  Adjusting the Output Voltage
      2. 7.4.2  Enable Functionality and Adjusting Undervoltage Lockout
      3. 7.4.3  Slow-Start or Tracking Pin
      4. 7.4.4  Sequencing
      5. 7.4.5  Constant Switching Frequency and Timing Resistor (RT/CLK Pin)
      6. 7.4.6  Overcurrent Protection
      7. 7.4.7  Frequency Shift
      8. 7.4.8  Reverse Overcurrent Protection
      9. 7.4.9  Synchronize Using the RT/CLK Pin
      10. 7.4.10 Power Good (PWRGD Pin)
      11. 7.4.11 Overvoltage Transient Protection
      12. 7.4.12 Thermal Shutdown
      13. 7.4.13 Small-Signal Model for Loop Response
      14. 7.4.14 Simple Small-Signal Model for Peak-Current-Mode Control
      15. 7.4.15 Small-Signal Model for Frequency Compensation
  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 Selecting the Switching Frequency
        2. 8.2.2.2 Output Inductor Selection
        3. 8.2.2.3 Output Capacitor
        4. 8.2.2.4 Input Capacitor
        5. 8.2.2.5 Slow-Start Capacitor
        6. 8.2.2.6 Bootstrap Capacitor Selection
        7. 8.2.2.7 Output-Voltage and Feedback-Resistor Selection
        8. 8.2.2.8 Compensation
        9. 8.2.2.9 Power-Dissipation Estimate
      3. 8.2.3 Application Curves
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 接收文档更新通知
    3. 11.3 支持资源
    4. 11.4 Trademarks
    5. 11.5 静电放电警告
    6. 11.6 术语表
  12. 12Mechanical, Packaging, and Orderable 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

Enable Functionality and Adjusting Undervoltage Lockout

The VIN pin voltage on the VIN pin falling below 2.6 V disables the TPS54388C-Q1 device. If an application requires a higher undervoltage lockout (UVLO), use the EN pin as shown in Figure 7-2 to adjust the input voltage UVLO by using two external resistors. TI recommends using the EN resistors to set the UVLO falling threshold (V(STOP)) above 2.6 V. Set the rising threshold (V(START)) to provide enough hysteresis to allow for any input supply variations. The EN pin has an internal pullup current source that provides the default condition of TPS54388C-Q1 operation when the EN pin floats. Once the EN pin voltage exceeds 1.25 V, the circuitry adds an additional 1.6 μA of hysteresis. Pulling the EN pin below 1.18 V removes the 1.6 μA. This additional current facilitates input voltage hysteresis.

GUID-4FC29F07-3CD3-40F3-8B9B-8F714D667655-low.gifFigure 7-2 Adjustable Undervoltage Lockout
Equation 2. GUID-915DB804-ECEF-437B-AE8B-667EE702D03F-low.gif

where

  • V(ENFALLING) = 1.18 V
  • V(ENRISING) = 1.25 V
  • I(1) = 1.6 µA
  • I(hys) = 1.6 µA
Equation 3. GUID-5E8802D6-B18A-400C-A99D-27458759AE23-low.gif