SLVS351Q September   2002  – June 2025 TPS796

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 Electrical Characteristics
    6. 5.6 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 Active Discharge (New Chip)
      2. 6.3.2 Shutdown
      3. 6.3.3 Start-Up
      4. 6.3.4 Undervoltage Lockout (UVLO)
      5. 6.3.5 Regulator Protection
        1. 6.3.5.1 Current Limit
        2. 6.3.5.2 Thermal Shutdown
    4. 6.4 Device Functional Modes
      1. 6.4.1 Normal Operation
      2. 6.4.2 Dropout Operation
      3. 6.4.3 Disabled
  8. 7 Application 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 Feed-forward Capacitor (CFF)
      4. 7.1.4 Adjustable Configuration
      5. 7.1.5 Load Transient Response
      6. 7.1.6 Dropout Voltage
        1. 7.1.6.1 Exiting Dropout
      7. 7.1.7 Noise Reduction Pin (legacy chip)
      8. 7.1.8 Power Dissipation (PD)
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
      3. 7.2.3 Application Curves
      4. 7.2.4 Best Design Practices
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
        1. 7.4.1.1 Board Layout Recommendation to Improve PSRR and Noise Performance
        2. 7.4.1.2 Regulator Mounting
        3. 7.4.1.3 Estimating Junction Temperature
      2. 7.4.2 Layout Examples
  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

Package Options

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

7.1.6.1 Exiting Dropout

Some applications have transients that place the LDO into dropout, such as slower ramps on VIN during start-up. As with other LDOs, the output can overshoot on recovery from these conditions. A ramping input supply causes an LDO to overshoot on start-up, as shown in Figure 7-3, when the slew rate and voltage levels are in the correct range. Use an enable signal to avoid this condition.

TPS796 Start-Up Into DropoutFigure 7-3 Start-Up Into Dropout

Line transients out of dropout can also cause overshoot on the output of the regulator. These overshoots are caused by the error amplifier having to drive the gate capacitance of the pass element and bring the gate back to the correct voltage for proper regulation. Figure 7-4 illustrates what is happening internally with the gate voltage and how overshoot can be caused during operation. When the LDO is placed in dropout, the gate voltage (VGS) is pulled all the way down to ground to give the pass device the lowest on-resistance as possible. However, if a line transient occurs when the device is in dropout, the loop is not in regulation and can cause the output to overshoot until the loop responds and the output current pulls the output voltage back down into regulation. If these transients are not acceptable, then continue to add input capacitance in the system until the transient is slow enough to reduce the overshoot.

TPS796 Line Transients From DropoutFigure 7-4 Line Transients From Dropout