SLVS788D February   2009  – November 2016 TPS22951

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configurations and Functions
  6. 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 Timing Requirements
    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 Current Limit
      2. 8.3.2 Power Good Indication
      3. 8.3.3 EN and DET inputs
      4. 8.3.4 Thermal Shutdown
    4. 8.4 Device Functional Modes
  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
      3. 9.2.3 Application Curve
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Thermal Considerations
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, 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

9 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.

9.1 Application Information

The input to output voltage drop in the device is determined by the RON of the device and the load current. The RON of the device depends upon the VCC condition of the device. Refer to Figure 1 rON vs VCC to determine the rON of the device based upon the VCC condition. Use Equation 1 to calculate the input to output voltage drop:

Equation 1. TPS22951 Eq05_delta_slvsct5.gif

where

  • ΔV = voltage drop from VCC to PWR
  • ILOAD = load current
  • RON = ON-Resistance of the device for a specific VCC

9.2 Typical Application

This application demonstrates how the TPS22951 can be used to protect against a short-circuit event. In this application, the PWR node is accidentally shorted to ground.

TPS22951 typ_app_slvs788_PG.gif Figure 12. Typical Application Circuit

9.2.1 Design Requirements

For this design example, use the input parameters given in Table 2:

Table 2. Design Parameters

DESIGN PARAMTER EXAMPLE VALUE
Power Supply Maximum DC Output Current 2 A
Load 1 Current Consumption 1 A

9.2.2 Detailed Design Procedure

The power supply provides power to multiple loads. In the event that Load 2 is shorted to ground, the power supply must continue providing power to Load 1. The power supply can provide 2-A continuous current. Load 1 consumes 1-A continuous current. The TPS22951 is used to ensure that Load 2 consumes less than 1-A continuous current. This ensures that the power supply can provide power to Load 1 even in the case that Load 2 is shorted to ground.

9.2.3 Application Curve

TPS22951 g_devenshrtcir_lvs788.gif Figure 13. Device Enabled into Short-Circuit