SBVS254D February   2018  – August 2019 TPS7A05

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application Circuit
      2.      Ground Current vs Output Current
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin 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 Excellent Transient Response
      2. 7.3.2 Active Discharge
      3. 7.3.3 Low IQ in Dropout
      4. 7.3.4 Undervoltage Lockout (UVLO)
      5. 7.3.5 Enable
      6. 7.3.6 Internal Foldback Current Limit
      7. 7.3.7 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Normal Mode
      2. 7.4.2 Dropout Mode
      3. 7.4.3 Disable Mode
  8. 8 Application 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 Special Considerations When Ramping Down VIN and Enable
      4. 8.1.4 Load Transient Response
      5. 8.1.5 Dropout Voltage
        1. 8.1.5.1 Behavior When Transitioning From Dropout Into Regulation
        2. 8.1.5.2 Behavior of Output Resulting From Line Transient When in Dropout
      6. 8.1.6 Undervoltage Lockout (UVLO) Operation
      7. 8.1.7 Power Dissipation (PD)
        1. 8.1.7.1 Estimating Junction Temperature
        2. 8.1.7.2 Recommended Area for Continuous Operation
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Design Considerations
      3. 8.2.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Spice Models
      2. 11.1.2 Device Nomenclature
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Community 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

8.1.5.1 Behavior When Transitioning From Dropout Into Regulation

Some applications may have transients that place the device into dropout, especially as this device can be powered from a battery with high ESR. A typical application with these conditions is using a stack of two 1.55-V coin-cell batteries with an ESR of 30 Ω to create a 2.5-V rail and experiencing a load transient from 1 µA to 25 mA. This load transient causes the input supply to drop 750 mV, placing the device into dropout.

The load transient saturates the output stage of the error amplifier when the pass element is driven fully on, making the pass element function like a resistor from VIN to VOUT. The error amplifier response time to this load transient is limited because the error amplifier must first recover from saturation and then place the pass element back into active mode. During this time VOUT overshoots because the pass element is functioning as a resistor from VIN to VOUT. This device uses a loop pulldown circuit to help mitigate the overshoot.

If operating under these conditions, applying a higher dc load or increasing the output capacitance reduces the overshoot because these solutions provide a path to dissipate the excess charge.