ZHCSBP7C October   2013  – December 2018 TPS24750 , TPS24751

UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
    1.     Device Images
      1.      应用原理图 (12V/10A)
      2.      瞬态输出短路响应
  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 Parameter Measurement Information
  9. 9 Detailed Descriptions
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1  DRAIN
      2. 9.3.2  EN
      3. 9.3.3  FLTb
      4. 9.3.4  GATE
      5. 9.3.5  GND
      6. 9.3.6  IMON
      7. 9.3.7  OUT
      8. 9.3.8  OV
      9. 9.3.9  PGb
      10. 9.3.10 PROG
      11. 9.3.11 SENSE
      12. 9.3.12 TIMER
      13. 9.3.13 VCC
    4. 9.4 Device Functional Modes
      1. 9.4.1 Board Plug-In
      2. 9.4.2 Inrush Operation
      3. 9.4.3 Action of the Constant-Power Engine
      4. 9.4.4 Circuit Breaker and Fast Trip
      5. 9.4.5 Automatic Restart
      6. 9.4.6 Start-Up with Short on Output
      7. 9.4.7 PGb, FLTb, and Timer Operations
        1. 9.4.7.1 Overtemperature Shutdown
        2. 9.4.7.2 Start-Up of Hot-Swap Circuit by VCC or EN
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Power-Limited Start-Up
          1. 10.2.2.1.1 STEP 1. Choose RSENSE, RSET, and RIMON
          2. 10.2.2.1.2 STEP 2. Choose Power-Limit Value, PLIM, and RPROG
          3. 10.2.2.1.3 STEP 3. Choose Output Voltage Rising Time, tON, and Timing Capacitor CT
          4. 10.2.2.1.4 STEP 4. Calculate the Retry-Mode Duty Ratio
          5. 10.2.2.1.5 STEP 5. Select R1, R2, and R3 for UV and OV
          6. 10.2.2.1.6 STEP 6. Choose R4, R5, and C1
        2. 10.2.2.2 Alternative Design Example: Gate Capacitor (dv/dt) Control in Inrush Mode
        3. 10.2.2.3 Additional Design Considerations
          1. 10.2.2.3.1 Use of PGb
          2. 10.2.2.3.2 Output Clamp Diode
          3. 10.2.2.3.3 Gate Clamp Diode
          4. 10.2.2.3.4 Bypass Capacitors
          5. 10.2.2.3.5 Output Short-Circuit Measurements
      3. 10.2.3 Application Curves
    3. 10.3 System Examples
  11. 11Power Supply Recommendations
    1. 11.1 Transient Thermal Impedance
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13器件和文档支持
    1. 13.1 文档支持
      1. 13.1.1 相关文档
    2. 13.2 相关链接
    3. 13.3 接收文档更新通知
    4. 13.4 社区资源
    5. 13.5 商标
    6. 13.6 静电放电警告
    7. 13.7 Export Control Notice
    8. 13.8 术语表
  14. 14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

9.4.3 Action of the Constant-Power Engine

Figure 32 illustrates the operation of the constant-power engine during start-up. The circuit used to generate the waveforms of Figure 32 was programmed to a power limit of 21 W by means of the resistor connected between PROG and GND. At the moment current begins to flow through the internal FET, a voltage of 12 V appears across it (input voltage VVCC = 12 V), and the constant-power engine therefore allows a current of 1.75 A (equal to 21 W divided by 12 V) to flow. This current increases in inverse ratio as the drain-to-source voltage diminishes, so as to maintain a constant dissipation of 21 W. The constant-power engine adjusts the current by altering the reference signal fed to the current limit amplifier. The lower part of Figure 32 shows the measured power dissipated in the internal FET, labeled FET PWR, remaining substantially constant during this period of operation, which ends when the current through the FET reaches the current limit ILIM. This behavior can be considered a form of foldback limiting, but unlike the standard linear form of foldback limiting, it allows the power device to operate near its maximum capability, thus reducing the start-up time.

TPS24750 TPS24751 Figure32a_ComputationPowerStress.gifFigure 32. Computation of Power Stress During Startup