SBVS437B December   2022  – February 2024 TPS7A21-Q1

PRODMIX  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Smart Enable (EN)
      2. 6.3.2 Low Output Noise
      3. 6.3.3 Active Discharge
      4. 6.3.4 Dropout Voltage
      5. 6.3.5 Foldback Current Limit
      6. 6.3.6 Undervoltage Lockout
      7. 6.3.7 Thermal Overload Protection (TSD)
    4. 6.4 Device Functional Modes
      1. 6.4.1 Device Functional Mode Comparison
      2. 6.4.2 Normal Operation
      3. 6.4.3 Dropout Operation
      4. 6.4.4 Disabled
  8. 7 Applications and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Recommended Capacitor Types
      2. 7.1.2 Input and Output Capacitor Requirements
      3. 7.1.3 Load Transient Response
      4. 7.1.4 Undervoltage Lockout (UVLO) Operation
      5. 7.1.5 Power Dissipation (PD)
      6. 7.1.6 Estimating Junction Temperature
      7. 7.1.7 Recommended Area For Continuous Operation
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Power Dissipation and Device Operation
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Device Nomenclature
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information
    1. 10.1 Mechanical Data

Package Options

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

7.1.4 Undervoltage Lockout (UVLO) Operation

The UVLO circuit makes sure that the device remains disabled before the input supply reaches the minimum operational voltage range, and makes sure that the device shuts down when the input supply collapses. Figure 7-2 shows the UVLO circuit response to various input voltage events. The diagram is separated into the following parts:

  • Region A: The device does not start until the input reaches the UVLO rising threshold.
  • Region B: Normal operation, regulating device.
  • Region C: Brownout event above the UVLO falling threshold (UVLO rising threshold – UVLO hysteresis). The output falls out of regulation but the device remains enabled.
  • Region D: Normal operation, regulating device.
  • Region E: Brownout event below the UVLO falling threshold. The device is disabled in most cases and the output falls because of the load and active discharge circuit. The device is re-enabled when the UVLO rising threshold is reached by the input voltage and a normal start-up follows.
  • Region F: Normal operation followed by the input falling to the UVLO falling threshold.
  • Region G: The device is disabled when the input voltage falls below the UVLO falling threshold to 0V. The output falls because of the load and active discharge circuit.

GUID-E419E06E-53E5-4A7F-8FB8-D69130128168-low.gifFigure 7-2 Typical UVLO Operation