JAJSQV1A July   2023  – October 2023 TPS7H2140-SEP

PRODUCTION DATA  

  1.   1
  2. 1 特長
  3. 2 アプリケーション
  4. 3 概要
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 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 Switching Characteristics
    7. 6.7 Typical Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Pin Current and Voltage Conventions
      2. 8.3.2 Accurate Current Sense
      3. 8.3.3 Adjustable Current Limit
      4. 8.3.4 Inductive-Load Switching-Off Clamp
      5. 8.3.5 Fault Detection and Reporting
        1. 8.3.5.1 Diagnostic Enable Function
        2. 8.3.5.2 Multiplexing of Current Sense
        3. 8.3.5.3 Fault Table
        4. 8.3.5.4 FAULT Reporting
      6. 8.3.6 Full Diagnostics
        1. 8.3.6.1 Short-to-GND and Overload Detection
        2. 8.3.6.2 Open-Load Detection
          1. 8.3.6.2.1 Channel On
          2. 8.3.6.2.2 Channel Off
        3. 8.3.6.3 Short-to-Input Detection
        4. 8.3.6.4 Reverse Polarity Detection
        5. 8.3.6.5 Thermal Fault Detection
          1. 8.3.6.5.1 Thermal Shutdown
      7. 8.3.7 Full Protections
        1. 8.3.7.1 UVLO Protection
        2. 8.3.7.2 Loss-of-GND Protection
        3. 8.3.7.3 Protection for Loss of Power Supply
        4. 8.3.7.4 Reverse-Current Protection
        5. 8.3.7.5 MCU I/O Protection
      8. 8.3.8 Parallel Operation
    4. 8.4 Device Functional Modes
      1. 8.4.1 Working Modes
  10. 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
      3. 9.2.3 Application Curves
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Examples
        1. 9.4.2.1 Without a GND Network
        2. 9.4.2.2 With a GND Network
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 ドキュメントの更新通知を受け取る方法
    3. 10.3 サポート・リソース
    4. 10.4 Trademarks
    5. 10.5 静電気放電に関する注意事項
    6. 10.6 用語集
  12. 11Mechanical, Packaging, and Orderable Information

パッケージ・オプション

メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報

8.3.3 Adjustable Current Limit

A high-accuracy current limit allows high reliability of the design. It protects the load and the power supply from overstressing during short-circuit-to-GND or power-up conditions. The current limit can also save system cost by reducing the size of PCB traces and connectors, and the capacity of the preceding power stage.

When a current-limit threshold is hit, a closed loop activates immediately. The output current is clamped at the set value, and a fault is reported out. The device heats up due to the high power dissipation on the power FET. If thermal shutdown occurs, the current limit is set to ICL_TSD (if set externally) or ICL_INTERNAL_TSD (when using internal) to reduce the power dissipation on the power FET. See Figure 8-4 for more details.

The device has two current-limit thresholds.

  • Internal current limit – The internal current limit is fixed at ICL_INTERNAL, typically 11 A. Tie the CL pin directly to the device GND for large-transient-current applications.
  • External adjustable current limit – An external resistor is used to set the current-limit threshold. Use the Equation 5 and Equation 6 to calculate the RCL. VCL_TH (0.8 V) is the internal band-gap voltage. KCL (2500) is the ratio of the output current and the current-limit set value. It is constant across the temperature and supply voltage. The external adjustable current limit allows the flexibility to set the current limit value by applications.
Equation 5. I C L = V C L _ T H R C L = I O U T     K C L
Equation 6. R C L = V C L _ T H   × K C L     I O U T
GUID-20230306-SS0I-VKP5-VXVD-FC7M39XPBHCH-low.svg Figure 8-4 Current-Limit Block Diagram

Note that if using a GND network which causes a level shift between the device GND and board GND, the CL pin must be connected with device GND.

For better protection from a hard short-to-GND condition (when the ENx pins are enabled, a short to GND occurs suddenly), the device implements a fast-trip protection to turn off the related channel before the current-limit closed loop is set up. The fast-trip response time is less than 1 μs, typically. With this fast response, the device can achieve better inrush current-suppression performance.