SLVSDK7C April   2017  – February 2020 TPS22971

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin 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 Switching Characteristics
    7. 6.7 Typical DC Characteristics
    8. 6.8 Typical AC 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 On and Off Control
      2. 8.3.2 Controlled Turn-On
      3. 8.3.3 Power Good (PG)
      4. 8.3.4 Quick Output Discharge (QOD)
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Thermal Consideration
      2. 9.1.2 PG Pull Up Resistor
      3. 9.1.3 Power Sequencing
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Maximum Voltage Drop and On-Resistance
        2. 9.2.2.2 Managing Inrush Current
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  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

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.3.2 Controlled Turn-On

The TPS22971 has controlled Turn-On for inrush current control. A capacitor to GND on the CT pin adjusts the slew rate. For a given input voltage and desired slew rate, Equation 1 can be used to find the required CT value. For calculated CT values less than 220 pF, use 0 pF instead when solving for tON and tPG,ON.

Equation 1. TPS22971 tps22971x-equation-01.gif

where

  • CT is the capacitor on the CT pin (in pF)
  • VIN is the input voltage (in V)
  • SR is the desired slew rate (in V/µs)

The CT value determined in Equation 1 can be used to find the total Turn-On time, tON, in Equation 2 or Equation 3 depending on VIN.

Equation 2. TPS22971 tps22971x-equation-02.gif
Equation 3. TPS22971 tps22971x-equation-03.gif

where

  • tON is the Turn-On time (in µs)
  • CT is the capacitor on the CT pin (in pF)
  • VIN is the input voltage (in V)