JAJSN24A November   2021  – June 2022 TPS22953-Q1 , TPS22954-Q1

PRODUCTION DATA  

  1. 1 特長
  2. 2 アプリケーション
  3. 3 概要
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  ESD Ratings
    3.     Recommended Operating Conditions
    4. 7.3  Thermal Information
    5. 7.4  Electrical Characteristics
    6. 7.5  Electrical Characteristics – VBIAS = 5 V
    7. 7.6  Electrical Characteristics – VBIAS = 3.3 V
    8. 7.7  Electrical Characteristics – VBIAS = 2.5 V
    9. 7.8  Switching Characteristics – CT = 1000 pF
    10. 7.9  Switching Characteristics – CT = 0 pF
    11. 7.10 Typical DC Characteristics
    12. 7.11 Typical Switching Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1  On and Off Control (EN Pin)
      2. 9.3.2  Voltage Monitoring (SNS Pin)
      3. 9.3.3  Power Good (PG Pin)
      4. 9.3.4  Supervisor Fault Detection and Automatic Restart
      5. 9.3.5  Manual Restart
      6. 9.3.6  Thermal Shutdown
      7. 9.3.7  Reverse Current Blocking (TPS22953-Q1 Only)
      8. 9.3.8  Quick Output Discharge (QOD) (TPS22954-Q1 Only)
      9. 9.3.9  VIN and VBIAS Voltage Range
      10. 9.3.10 Adjustable Rise Time (CT Pin)
      11. 9.3.11 Power Sequencing
    4. 9.4 Device Functional Modes
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Input to Output Voltage Drop
      2. 10.1.2 Thermal Considerations
      3. 10.1.3 Automatic Power Sequencing
      4. 10.1.4 Monitoring a Downstream Voltage
      5. 10.1.5 Monitoring the Input Voltage
      6. 10.1.6 Break-Before-Make Power MUX (TPS22953-Q1 Only)
      7. 10.1.7 Make-Before-Break Power MUX (TPS22953-Q1 Only)
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Inrush Current
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Documentation Support
      1. 13.1.1 Related Documentation
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 サポート・リソース
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, 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

10.1.6 Break-Before-Make Power MUX (TPS22953-Q1 Only)

The reverse current blocking feature of the TPS22953-Q1 makes it suitable for power multiplexing (MUXing) between two power supplies with different voltages. The SNS and PG pin can be configured to implement break-before-make logic. The circuit in Figure 10-4 shows how the detection of power supply 1 can be used to disable the load switch for power supply 2. By tying the SNS of Load Switch 1 directly to the input, its PG pin is pulled up as soon as the device is enabled.

GUID-20211110-SS0I-DP5W-RGXN-JXQ4LHGR98XX-low.pngFigure 10-4 Break-Before-Make Power MUX Schematic

The break-before-make logic ensures that power supply 2 is completely disconnected before power supply 1 is connected. This approach provides very robust reverse current blocking. However, in most cases, this aproach also results in a dip in the output voltage when switching between supplies.

The amount of voltage dip depends on the loading, the output capacitance, and the turn-on delay of the load switch. In this application, leaving the CT pin open results in the shortest turn-on delay and minimizes the output voltage dip.

Table 10-1 summarizes the logic of the PG Signal for Figure 10-4.

Table 10-1 Break-Before-Make PG Signal
PG SignalIndication
HPower supply 1 not present. System powered from power supply 2.
LPower supply 1 present. System powered from power supply 1.