SBVS446A August   2023  – January 2024 TPS7A53B

PRODUCTION DATA  

  1.   1
  2. Features
  3. Applications
  4. Description
  5. Pin Configuration and Functions
  6. 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. Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Voltage Regulation Features
        1. 6.3.1.1 DC Regulation
        2. 6.3.1.2 AC and Transient Response
      2. 6.3.2 System Start-Up Features
        1. 6.3.2.1 Programmable Soft-Start (NR/SS Pin)
        2. 6.3.2.2 Internal Sequencing
          1. 6.3.2.2.1 Enable (EN)
          2. 6.3.2.2.2 Undervoltage Lockout (UVLO) Control
          3. 6.3.2.2.3 Active Discharge
        3. 6.3.2.3 Power-Good Output (PG)
      3. 6.3.3 Internal Protection Features
        1. 6.3.3.1 Foldback Current Limit (ICL)
        2. 6.3.3.2 Thermal Protection (Tsd)
    4. 6.4 Device Functional Modes
      1. 6.4.1 Regulation
      2. 6.4.2 Disabled
      3. 6.4.3 Current Limit Operation
  8. Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1  Recommended Capacitor Types
        1. 7.1.1.1 Input and Output Capacitor Requirements (CIN and COUT)
        2. 7.1.1.2 Noise-Reduction and Soft-Start Capacitor (CNR/SS)
        3. 7.1.1.3 Feed-Forward Capacitor (CFF)
      2. 7.1.2  Soft-Start and Inrush Current
      3. 7.1.3  Optimizing Noise and PSRR
      4. 7.1.4  Charge Pump Noise
      5. 7.1.5  Current Sharing
      6. 7.1.6  Adjustable Operation
      7. 7.1.7  Power-Good Operation
      8. 7.1.8  Undervoltage Lockout (UVLO) Operation
      9. 7.1.9  Dropout Voltage (VDO)
      10. 7.1.10 Device Behavior During Transition From Dropout Into Regulation
      11. 7.1.11 Load Transient Response
      12. 7.1.12 Reverse Current Protection Considerations
      13. 7.1.13 Power Dissipation (PD)
      14. 7.1.14 Estimating Junction Temperature
      15. 7.1.15 TPS7A53EVM Thermal Analysis
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
        1. 7.4.1.1 Board Layout
      2. 7.4.2 Layout Example
  9. 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. Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

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

Undervoltage Lockout (UVLO) Operation

The UVLO circuit makes sure that the device remains disabled before the input or bias supplies reach the minimum operational voltage range, and that the device shuts down when the input supply or bias supply falls too low.

The UVLO circuit has a minimum response time of several microseconds to fully assert. During this time, a downward line transient below approximately 0.8V causes the UVLO to assert for a short time; however, the UVLO circuit does not have enough stored energy to fully discharge the internal circuits inside the device. When the UVLO circuit does not fully discharge, the internal circuits of the output are not fully disabled.

The effect of the downward line transient can be mitigated by either using a larger input capacitor to limit the fall time of the input supply when operating near the minimum VIN, or by using a bias rail.

Figure 7-2 shows the UVLO circuit response to various input voltage events. The diagram can be separated into the following regions:

  • Region A: The device does not turn on until the input reaches the UVLO rising threshold.
  • Region B: Normal operation with a regulated output.
  • Region C: Brownout event above the UVLO falling threshold (UVLO rising threshold – UVLO hysteresis). The output can fall out of regulation but the device is still enabled.
  • Region D: Normal operation with a regulated output.
  • 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 reenabled when the UVLO rising threshold is reached by the input voltage and a normal start-up then 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-A1BABB7D-850B-46E5-A135-59A02004A21E-low.gifFigure 7-2 Typical UVLO Operation