ZHCSP75A July   2022  – December 2022 TPS1HC30-Q1

PRODUCTION DATA  

  1. 1 特性
  2. 2 应用
  3. 3 说明
  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 建议运行条件
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 SNS Timing Characteristics
    7. 6.7 Switching Characteristics
    8. 6.8 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 Accurate Current Sense
      2. 8.3.2 Programmable Current Limit
        1. 8.3.2.1 Capacitive Charging
      3. 8.3.3 Inductive-Load Switching-Off Clamp
      4. 8.3.4 Full Protections and Diagnostics
        1. 8.3.4.1  Short-Circuit and Overload Protection
        2. 8.3.4.2  Open-Load and Short-to-Battery Detection
        3. 8.3.4.3  Short-to-Battery Detection
        4. 8.3.4.4  Reverse-Polarity and Battery Protection
        5. 8.3.4.5  Latch-Off Mode
        6. 8.3.4.6  Thermal Protection Behavior
        7. 8.3.4.7  UVLO Protection
        8. 8.3.4.8  Loss of GND Protection
        9. 8.3.4.9  Loss of Power Supply Protection
        10. 8.3.4.10 Reverse Current Protection
        11. 8.3.4.11 Protection for MCU I/Os
      5. 8.3.5 Diagnostic Enable Function
    4. 8.4 Device Functional Modes
      1. 8.4.1 Working Mode
  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 Dynamically Changing Current Limit
        2. 9.2.2.2 EMC Transient Disturbances Test
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
        1. 9.4.2.1 Without a GND Network
        2. 9.4.2.2 With a GND Network
      3. 9.4.3 Thermal Considerations
  10. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 接收文档更新通知
    3. 10.3 支持资源
    4. 10.4 Trademarks
    5. 10.5 静电放电警告
    6. 10.6 术语表
  11. 11Mechanical, Packaging, and Orderable Information

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9.2.2 Detailed Design Procedure

To keep maximum voltage on the SNS pin at an acceptable range for the system, use the following equation to calculate the RSNS. To achieve better current sense accuracy. A 1% accuracy or better resistor is preferred.

Equation 13. (VSNSFH – VHR) × KSNS / ILOAD,max ≤ RSNS ≤ VADC,min × KSNS / ILOAD,min

Table 9-1 Typical Application

Parameter

Value

VDIAG_EN

5 V

ILOAD,max

6 A

ILOAD,min

20 mA

VADC,min

5 mV

VHR

1 V
For this application, an RSNS value of approximately 1 kΩ can be chosen to satisfy the equation requirements.

Equation 14. (5 V – 1 V) × 1814 / 6 A ≤ ≅1 kΩ ≤ 5 mV × 11814 / 20 mA
In other applications, more emphasis can be put on the lower end measurable values which increases RSNS. Likewise, if the higher currents are of more interest the RSNS can be decreased. Note that the maximum current that can be measured without saturation is 12 A.

Having the maximum SNS voltage scale with the DIAG_EN voltage removes the need for a Zener diode on the SNS pin going to the ADC.

To set the programmable current limit value at 7 A, use the following equation to calculate the RLIM.

Equation 15. RLIM = KCL / ILIM = 90 / 7 = 12.8 kΩ

TI recommends RPROT = 5 kΩ to ensure the current going into the digital pins (EN, DIAG_EN, LATCH) is limited.

TI recommends a 1-kΩ resistor and 200-V, 0.2-A diode (BAS21 for example) for the GND network.