ZHCSMM1C April   2023  – February 2024 TPS274C65

PRODUCTION DATA  

  1.   1
  2. 1 特性
  3. 2 应用
  4. 3 说明
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
    1.     7
  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 SPI Timing Requirements
    8. 6.8 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 Diagrams
      2. 8.3.2 SPI Mode Operation
        1. 8.3.2.1 Diagnostic Bit Behavior
      3. 8.3.3 Programmable Current Limit
        1. 8.3.3.1 Inrush Current Handling
      4. 8.3.4 DO_EN Feature
      5. 8.3.5 Protection Mechanisms
        1. 8.3.5.1 Overcurrent Protection
        2. 8.3.5.2 Short Circuit Protection
          1. 8.3.5.2.1 VS During Short-to-Ground
        3. 8.3.5.3 Inductive-Load Switching-Off Clamp
        4. 8.3.5.4 Inductive Load Demagnetization
        5. 8.3.5.5 Thermal Shutdown
        6. 8.3.5.6 Undervoltage protection on VS
        7. 8.3.5.7 Undervoltage Lockout on Low Voltage Supply (VDD_UVLO)
        8. 8.3.5.8 Power-Up and Power-Down Behavior
        9. 8.3.5.9 Reverse Current Blocking
      6. 8.3.6 Diagnostic Mechanisms
        1. 8.3.6.1 Current Sense
          1. 8.3.6.1.1 RSNS Value
            1. 8.3.6.1.1.1 SNS Output Filter
        2. 8.3.6.2 Fault Indication
          1. 8.3.6.2.1 Current Limit Behavior
        3. 8.3.6.3 Short-to-Battery and Open-Load Detection
        4. 8.3.6.4 On-State Wire-Break Detection
        5. 8.3.6.5 Off State Wire-Break Detection
        6. 8.3.6.6 ADC
      7. 8.3.7 LED Driver
    4. 8.4 Device Functional Modes
      1. 8.4.1 OFF/POR
      2. 8.4.2 INIT
      3. 8.4.3 Active
    5. 8.5 TPS274C65BS Available Registers List
    6. 8.6 TPS274C65 Registers
  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
        1. 9.2.2.1 IEC 61000-4-5 Surge
        2. 9.2.2.2 Loss of GND
        3. 9.2.2.3 Paralleling Channels
      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 Example
  11. 10Device and Documentation Support
    1. 10.1 接收文档更新通知
    2. 10.2 支持资源
    3. 10.3 Trademarks
    4. 10.4 静电放电警告
    5. 10.5 术语表
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

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8.3.5.2 Short Circuit Protection

The TPS274C65xS provides output short-circuit protection to ensure that the device will prevent current flow in the event of a low impedance path to GND, removing the risk of damage or significant supply droop. The TPS274C65xS is guaranteed to protect against short-circuit events regardless of the state of the ILIM pins and with up to 36 V supply at 125°C.

Figure 8-21 shows the behavior of the TPS274C65xS when the device is enabled into a short-circuit.

GUID-20240226-SS0I-4VQ6-112B-X1GN4MJW39BR-low.svg Figure 8-21 Enable into Short-Circuit Behavior

Due to the low impedance path, the output current will rapidly increase until it hits the current limit threshold. Due to series inductance and deglitch, the measured maximum current may temporarily exceed the ICL value defined as ICL_ENPS, however it will settle to the current limit.

In this state high power is dissipated in the FET, so eventually the internal thermal protection temperature for the FET is reached and the device safely shuts down. If the device is not configured in latch mode, the device will wait tRETRY amount of time and turn the channel back on.

Figure 8-22 shows the behavior of the TPS274C65xS when a short-circuit occurs when the device is in the on-state and already outputting current. When the internal pass FET is fully enabled, the current clamping settling time is slower so to ensure overshoot is limited, the device implements a fast trip level at a level IOVCR. When this fast trip threshold is hit, the device immediately shuts off for a short period of time before quickly re-enabling and clamping the current to ICL_Reg level after a brief transient overshoot to the ICL_ENPS level. The device will then keep the current clamped at the regulation current limit until the thermal shutdown temperature is hit and the device will safely shut-off.

GUID-20240226-SS0I-GMRV-LXVJ-VRKFNXMHQ6G2-low.svg Figure 8-22 On-State Short-Circuit Behavior

Soft Short- Circuit Behavior illustrated in Soft Short-Circuit Behavior shows the behavior of the TPS274C65xS when there is a small change in impedance that sends the load current above the ICL threshold. The current rises to ICL_LINPK since the FET is still in the linear mode. Then the current limit kicks in and the current drops to the ICL value.

GUID-20240226-SS0I-VN4L-5SHM-S7VHDFQ2KM9B-low.svg Figure 8-23 Soft Short-Circuit Behavior

In all of these cases, the internal thermal shutdown is safe to hit repetitively. There is no device risk or lifetime reliability concerns from repeatedly hitting this thermal shutdown level.