SBVS067U January   2006  – September 2024 TPS737

PRODUCTION DATA  

  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 Thermal Information
    6. 5.6 Electrical Characteristics
    7. 5.7 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagrams
    3. 6.3 Feature Description
      1. 6.3.1 Output Noise
      2. 6.3.2 Internal Current Limit
      3. 6.3.3 Enable Pin and Shutdown
      4. 6.3.4 Reverse Current
    4. 6.4 Device Functional Modes
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Input and Output Capacitor Requirements
        2. 7.2.2.2 Dropout Voltage
        3. 7.2.2.3 Transient Response
      3. 7.2.3 Application Curves
    3. 7.3 Best Design Practices
    4. 7.4 Power Supply Recommendations
    5. 7.5 Layout
      1. 7.5.1 Layout Guidelines
        1. 7.5.1.1 Power Dissipation
        2. 7.5.1.2 Thermal Protection
        3. 7.5.1.3 Estimating Junction Temperature
      2. 7.5.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
        1. 8.1.1.1 Evaluation Modules
        2. 8.1.1.2 Spice Models
      2. 8.1.2 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

7.2.2.2 Dropout Voltage

The TPS737 uses an NMOS pass transistor to achieve extremely low dropout. When (VIN – VOUT) is less than the dropout voltage (VDO), the NMOS pass transistor is in the linear region of operation and the input-to-output resistance is the RDS(on) of the NMOS pass transistor.

For large step changes in load current, the TPS737 requires a larger voltage drop from VIN to VOUT to avoid degraded transient response. The boundary of this transient dropout region is approximately twice the DC dropout. Values of (VIN – VOUT) above this line provide normal transient response.

Operating in the transient dropout region can cause an increase in recovery time. The time required to recover from a load transient is a function of the magnitude of the change in load current rate, the rate of change in load current, and the available headroom (VIN-to-VOUT voltage drop). Under worst-case conditions [full-scale instantaneous load change with (VIN – VOUT) close to DC dropout levels], the TPS737 can take a couple of hundred microseconds to return to the specified regulation accuracy.