SBVS398A December   2021  – September 2022 TPS7A21

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 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 Smart Enable (EN)
      2. 7.3.2 Low Output Noise
      3. 7.3.3 Active Discharge
      4. 7.3.4 Dropout Voltage
      5. 7.3.5 Foldback Current Limit
      6. 7.3.6 Undervoltage Lockout
      7. 7.3.7 Thermal Overload Protection (TSD)
    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 Applications and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Recommended Capacitor Types
      2. 8.1.2 Input and Output Capacitor Requirements
      3. 8.1.3 Load Transient Response
      4. 8.1.4 Undervoltage Lockout (UVLO) Operation
      5. 8.1.5 Power Dissipation (PD)
      6. 8.1.6 Estimating Junction Temperature
      7. 8.1.7 Recommended Area For Continuous Operation
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Power Dissipation and Device Operation
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
        1. 8.4.1.1 DSBGA Mounting
        2. 8.4.1.2 DSBGA Light Sensitivity
      2. 8.4.2 Layout Example
  9. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Device Nomenclature
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  10. 10Mechanical, Packaging, and Orderable Information
    1. 10.1 Mechanical Data

7.3.3 Active Discharge

The regulator has an internal metal-oxide-semiconductor field-effect transistor (MOSFET) that connects a pulldown resistor between the output and ground pins when the device is disabled to actively discharge the output voltage. The voltage on IN must be high enough to turn on the pulldown MOSFET; when VIN is too low to provide sufficient VGS on the pulldown MOSFET, the pulldown circuit is not active. The active discharge circuit is activated by the enable pin, or by the voltage on IN falling below the undervoltage lockout (UVLO) threshold.

Do not rely on the active discharge circuit for discharging a large amount of output capacitance after the input supply has collapsed because reverse current can possibly flow from the output to the input. This reverse current flow can cause damage to the device. Limit reverse current to no more than 5% of the device rated current for only a short period of time.