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

7.3.2 Active Discharge

Devices with this option have an internal pulldown MOSFET that connects a 120-Ω resistor to ground when the device is disabled to actively discharge the output voltage. The active discharge circuit is activated when the device is disabled, in undervoltage lockout (UVLO), or in thermal shutdown.

The discharge time after disabling depends on the output capacitance (COUT) and the load resistance (RL) in parallel with the 120-Ω pulldown resistor. Equation 1 calculates the time constant:

Equation 1. TPS7A05 q_tau_bvs142.gif

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 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.