SLVSD88L July   2016  – August 2021 TPS61099

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Boost Controller Operation
      2. 8.3.2 Under-Voltage Lockout
      3. 8.3.3 Enable and Disable
      4. 8.3.4 Soft Start
      5. 8.3.5 Current Limit Operation
      6. 8.3.6 Output Short-to-Ground Protection
      7. 8.3.7 Over Voltage Protection
      8. 8.3.8 Down Mode Regulation and Pass-Through Operation
      9. 8.3.9 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Burst Mode Operation under Light Load Condition
      2. 8.4.2 Down Mode Regulation and Pass-Through Mode Operation
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application - 5 V Output Boost Converter
      1. 9.2.1 Design Requirements
        1. 9.2.1.1 Detailed Design Procedure
          1. 9.2.1.1.1 Custom Design With WEBENCH® Tools
          2. 9.2.1.1.2 Programming the Output Voltage
          3. 9.2.1.1.3 Maximum Output Current
          4. 9.2.1.1.4 Inductor Selection
          5. 9.2.1.1.5 Capacitor Selection
        2. 9.2.1.2 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Development Support
        1. 12.1.1.1 Custom Design With WEBENCH® Tools
      2. 12.1.2 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Support Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.4 Soft Start

After the EN pin is tied to high voltage, the TPS61099x begins to startup. At the beginning, the device operates at the boundary of Discontinuous Conduction Mode (DCM) and Continuous Conduction Mode (CCM), and the inductor peak current is limited to around 200 mA during this stage. When the output voltage is charged above approximately 1.6 V, the device starts the hysteretic current mode operation. The current limit threshold is gradually increasing to 0.7× ILIM within 500 µs. In this way, the soft start function reduces the inrush current during startup. After VOUT reaches the target value, soft start stage ends and the peak current is now determined by the output of an internal error amplifier which compares the feedback of the output voltage and the internal reference voltage.

The TPS61099x is able to start up with 0.7-V input voltage with larger than 3-kΩ load. However, if the load during startup is so heavy that the TPS61099x fails to charge the output voltage above 1.6 V, the TPS61099x can't start up successfully until the input voltage is increased or the load current is reduced. The startup time depends on input voltage and load current.