SBVS082K June   2007  – June 2024 TPS74901

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: IOUT = 50mA
    7. 5.7 Typical Characteristics: IOUT = 1 A
  7. Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagrams
    3. 6.3 Feature Description
      1. 6.3.1 Enable and Shutdown
      2. 6.3.2 Power-Good
      3. 6.3.3 Internal Current Limit
      4. 6.3.4 Thermal Protection
    4. 6.4 Device Functional Modes
      1. 6.4.1 Normal Operation
      2. 6.4.2 Dropout Operation
      3. 6.4.3 Disabled
  8. Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Input, Output, and BIAS Capacitor Requirements
      2. 7.1.2 Transient Response
      3. 7.1.3 Dropout Voltage
      4. 7.1.4 Output Noise
      5. 7.1.5 Programmable Soft-Start
      6. 7.1.6 Sequencing Requirements
    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 Power Dissipation
        2. 7.4.1.2 Thermal Considerations
      2. 7.4.2 Layout Example
  9. Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Device Nomenclature
      2. 8.1.2 Development Support
        1. 8.1.2.1 Evaluation Modules
        2. 8.1.2.2 Spice Models
    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

Detailed Design Procedure

First choose the bias, which must be at least 1.75V above the output voltage. A 3.3V rail is used to achieve this minimum voltage. For a minimal external component count and size, select the minimum capacitor sizes. CIN = 1µF, CBIAS = 1µF, and a COUT = 10µF. The COUT value was chosen to improve transient response. Using Table 7-2, R1 is set to 2.49kΩ and R2 is set to 4.99kΩ to create a 1.2V rail. The pullup resistor for PG is set to 10kΩ.