ZHCSU10P March   2000  – February 2025 LP2981-N

PRODUCTION DATA  

  1.   1
  2. 1 特性
  3. 2 应用
  4. 3 说明
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagrams
    3. 6.3 Feature Description
      1. 6.3.1 Output Enable
      2. 6.3.2 Dropout Voltage
      3. 6.3.3 Current Limit
        1. 6.3.3.1 Current Limit (Legacy Chip)
        2. 6.3.3.2 Current Limit (New Chip)
      4. 6.3.4 Undervoltage Lockout (UVLO)
      5. 6.3.5 Thermal Shutdown
      6. 6.3.6 Output Pulldown
    4. 6.4 Device Functional Modes
      1. 6.4.1 Normal Operation
      2. 6.4.2 Dropout Operation
      3. 6.4.3 Disabled
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Recommended Capacitor Types
        1. 7.1.1.1 Recommended Capacitors (Legacy Chip)
          1. 7.1.1.1.1 Tantalum Capacitors
          2. 7.1.1.1.2 Ceramic Capacitors
          3. 7.1.1.1.3 Aluminum Capacitors
        2. 7.1.1.2 Recommended Capacitors (New Chip)
      2. 7.1.2 Input and Output Capacitor Requirements
        1. 7.1.2.1 Input Capacitor
        2. 7.1.2.2 Output Capacitor
      3. 7.1.3 Estimating Junction Temperature
      4. 7.1.4 Power Dissipation (PD)
      5. 7.1.5 Reverse Current
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 ON and OFF Input Operation
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Nomenclature
    2. 8.2 第三方产品免责声明
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Related Documentation
    5. 8.5 支持资源
    6. 8.6 Trademarks
    7. 8.7 静电放电警告
    8. 8.8 术语表
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

7.1.5 Reverse Current

Excessive reverse current can damage this device. Reverse current flows through the intrinsic body diode of the pass transistor instead of the normal conducting channel. At high magnitudes, this current flow degrades the long-term reliability of the device.

Conditions where reverse current can occur are outlined in this section, all of which can exceed the absolute maximum rating of VOUT ≤ VIN + 0.3V.

  • If the device has a large COUT and the input supply collapses with little or no load current
  • The output is biased when the input supply is not established
  • The output is biased above the input supply

If reverse current flow is expected in the application, use external protection to protect the device. Reverse current is not limited in the device, so external limiting is required if extended reverse voltage operation is anticipated.

Figure 7-1 depicts one approach for protecting the device.

LP2981-N Example Circuit for Reverse Current Protection Using a Schottky Diode Figure 7-1 Example Circuit for Reverse Current Protection Using a Schottky Diode