ZHCSC46C February   2014  – June 2021 INA300


  1. 特性
  2. 应用
  3. 说明
  4. Revision History
  5. Pin Configuration and Functions
  6. Specifications
    1. 6.1 Absolute Maximum Ratings (1)
    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. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Selecting a Current-Sensing Resistor
        1. Selecting a Current-Sensing Resistor: Example
      2. 7.3.2 Setting The Current-Limit Threshold
        1. Resistor-Controlled Current Limit
        2. Voltage Source-Controlled Current Limit
      3. 7.3.3 Delay Setting
      4. 7.3.4 Alert Timing Response
      5. 7.3.5 Selectable Hysteresis
      6. 7.3.6 Alert Output
      7. 7.3.7 Noise Adjustment Factor (NAF)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Alert Mode
        1. Transparent Output Mode
        2. Latch Output Mode
      2. 7.4.2 Disable Mode
      3. 7.4.3 Input Filtering
      4. 7.4.4 Using the INA300 INA300 With Common-Mode Transients Above 36 V
  8. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Unidirectional Operation
        1. Design Requirements
        2. Detailed Design Procedure
        3. Application Curve
      2. 8.2.2 Bidirectional Operation
        1. Design Requirements
        2. Detailed Design Procedure
        3. Application Curve
      3. 8.2.3 Window Comparator
        1. Design Requirements
        2. Detailed Design Procedure
        3. Application Curve
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 接收文档更新通知
    3. 11.3 支持资源
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 术语表
  12. 12Mechanical, Packaging, and Orderable Information


机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)

Voltage Source-Controlled Current Limit

The second method for setting the limit voltage is to connect the LIMIT terminal to a programmable DAC (digital-to-analog converter) or other external voltage source. The benefit of this method is the ability to adjust the current limit to account for different threshold voltages that are used for different system operating conditions. For example, this method can be used in a system that has one current-limit threshold level that must be monitored during the power-up sequence but different thresholds must be monitored during other system operating modes.

In Table 7-3, VTRIP represents the overcurrent threshold the device is programmed to monitor for and VSOURCE is the programmed signal set to detect the VTRIP level. NAF is included in the VSOURCE equation for the 10-µs delay setting. This value equals 500 µV and is adjusts the operating point for the noise in the delay setting. The 50-µs and 100-µs delay settings do not use the NAF term in calculating the VSOURCE threshold. For these delay settings, the NAF term is omitted. See the Section 7.3.7 section for more details on the noise adjustment factor.

Table 7-3 Calculating the Limit Threshold Voltage Source, VSOURCE
VTRIPDesired current trip valueILOAD × RSENSE
VSOURCE (1)Programmed threshold limit voltageVTRIP + NAF
VSOURCE (1)Programmed signal set to detect the VTRIP levelVTRIP + 500 µV
NAF is used with the 10-µs delay setting. NAF can be omitted in the VSOURCE calculation for the 50-µs and 100-µs delay settings.

TI recommends using NAF in calculating the value for VSOURCE at the 10-µs delay setting. Removing NAF from the VSOURCE calculation at the 10-µs delay setting lowers the trigger point of the alert output. Lowering the trigger point results in the device issuing an overcurrent alert prior to reaching the corresponding VTRIP threshold. The averaging effect included with the 50-µs and 100-µs delay settings inherently eliminates the effect internal noise has on the threshold voltage.