JAJSL99 August   2021 TPS1653

PRODUCTION DATA  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
  4. 4 Revision History
  5. 5 Pin Configuration and 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 Timing Requirements
    7. 6.7 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Hot Plug-In and In-Rush Current Control
        1. 8.3.1.1 Thermal Regulation Loop
      2. 8.3.2  Undervoltage Lockout (UVLO)
      3. 8.3.3  Overload and Short Circuit Protection
        1. 8.3.3.1 Overload Protection
        2. 8.3.3.2 Short Circuit Protection
          1. 8.3.3.2.1 Start-Up With Short-Circuit On Output
      4. 8.3.4  Current Monitoring Output (IMON)
      5. 8.3.5  FAULT Response (FLT)
      6. 8.3.6  Power Good Output (PGOOD)
      7. 8.3.7  IN, P_IN, OUT and GND Pins
      8. 8.3.8  Thermal Shutdown
      9. 8.3.9  Low Current Shutdown Control (SHDN)
      10. 8.3.10 Enable Input (EN)
    4. 8.4 Device Functional Modes
  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 Programming the Current-Limit Threshold R(ILIM) Selection
        2. 9.2.2.2 Undervoltage Lockout and Overvoltage Set Point
        3. 9.2.2.3 Setting Output Voltage Ramp Time (tdVdT)
          1. 9.2.2.3.1 Support Component Selections RPGOOD and C(IN)
      3. 9.2.3 Application Curves
    3. 9.3 System Examples
      1. 9.3.1 48-V Power Amplifier Protection for Telecom Radios
  10. 10Power Supply Recommendations
    1. 10.1 Transient Protection
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 サポート・リソース
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

8.3.1.1 Thermal Regulation Loop

The average power dissipation within the eFuse during power up with a capacitive load can be calculated using Equation 3.

Equation 3. GUID-598A2132-FF26-451D-A6CE-243904BE271B-low.gif

System designs requiring to charge large output capacitors rapidly may result in an operating point that exceeds the power dissipation versus time boundary limits of the device defined by Figure 6-7 characteristic curve. This may result in increase in junction temperature beyond the device's maximum allowed junction temperature. To keep the junction temperature within the operating range, the thermal regulation control loop regulates the junction temperature at T(J_REG) , 145°C (typical) by controlling the inrush current profile and thereby limiting the power dissipation within the device automatically. An internal 1.3 sec (typical), t(Treg_timeout) timer starts from the instance the thermal regulation operation kicks in. If the output does not power up within this time then the internal FET is turned OFF. Subsequent operation of the device depends on the MODE configuration (Auto-Retry or latch OFF) setting as per the Table 8-2. The maximum time-out of 1.3 sec (typical) in thermal regulation loop operation ensures that the device and the system board does not heat up during steady fault conditions such as wake up with output short-circuit. This scheme ensures reliable power up operation.

Thermal regulation control loop is internally enabled during power up by V(IN), UVLO cycling and turn ON using SHDN control. Figure 8-2 illustrates performance of the device operating in thermal regulation loop during power up by V(IN) with a large output capacitor. The Thermal regulation loop gets disabled internally after the power up sequence when the internal FET's gate gets fully enhanced or when the t(Treg_timeout) of 1.3 sec (typical) time is elapsed.

GUID-20210805-CA0I-MLCD-BBCT-LVJ8LVZXFTTK-low.png
CdVdT = Open VIN = 35 V RILIM = 4.02 kΩ
Figure 8-2 Thermal Regulation Loop Response During Power Up With 4.7-mF Capacitive Load