SBVS363A December   2020  – April 2021 TPS7B87-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration 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 Switching Characteristics
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Power-Good (PG)
      2. 7.3.2 Adjustable Power-Good Delay Timer (DELAY)
      3. 7.3.3 Undervoltage Lockout
      4. 7.3.4 Thermal Shutdown
      5. 7.3.5 Current Limit
    4. 7.4 Device Functional Modes
      1. 7.4.1 Device Functional Mode Comparison
      2. 7.4.2 Normal Operation
      3. 7.4.3 Dropout Operation
      4. 7.4.4 Disabled
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Input and Output Capacitor Selection
      2. 8.1.2 Dropout Voltage
      3. 8.1.3 Reverse Current
      4. 8.1.4 Power Dissipation (PD)
        1. 8.1.4.1 Thermal Performance Versus Copper Area
        2. 8.1.4.2 Power Dissipation Versus Ambient Temperature
      5. 8.1.5 Estimating Junction Temperature
      6. 8.1.6 Pulling Up the PG Pin to a Different Voltage
      7. 8.1.7 Power-Good
        1. 8.1.7.1 Setting the Adjustable Power-Good Delay
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Input Capacitor
        2. 8.2.2.2 Output Capacitor
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Package Mounting
      2. 10.1.2 Board Layout Recommendations to Improve PSRR and Noise Performance
    2. 10.2 Layout Examples
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Device Nomenclature
      2. 11.1.2 Development Support
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Support Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

8.1.6 Pulling Up the PG Pin to a Different Voltage

Because the power-good (PG) pin is pulled up internally to the output rail, this pin cannot be pulled up to any voltage or wire AND'd like a typical open-drain PG output can be. If this signal must be pulled up to another logic level then an external circuit can be implemented using a PMOS transistor and a pullup resistor. Implementing the circuit shown in Figure 8-7 allows the outputs to be pulled up to any logic rail. If a PMOS transistor is used make sure to pick a transistor with a low threshold voltage as this will determine the output low voltage. this can also be done with a NMOS transistor, but it inverts the logic. This implementation also allows the outputs to be AND'd together like the traditional power-good pins.

GUID-60ECAE97-F52D-42D4-9850-B8BCB741AFE7-low.gif Figure 8-7 Additional Components for the PG Pin to be Pulled Up to Another Rail