SLVSHJ8 February   2024 TPS61299-Q1

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 Diagram
    3. 6.3 Feature Description
      1. 6.3.1  Boost Control Operation
      2. 6.3.2  Version Detection
      3. 6.3.3  Under-voltage Lockout
      4. 6.3.4  Switching Frequency
      5. 6.3.5  Input Current Limit
      6. 6.3.6  Enable and Disable
      7. 6.3.7  Soft-Start Timing
      8. 6.3.8  Down Mode
      9. 6.3.9  Pass-Through Operation
      10. 6.3.10 Output Short-to-Ground Protection
      11. 6.3.11 Thermal Shutdown
    4. 6.4 Device Functional Modes
      1. 6.4.1 Fast Load Transient Mode and Normal Mode
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application-Li-ion Battery to 5V Boost Converter Under Fast Mode
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Maximum Output Current
        2. 7.2.2.2 Inductor Selection
        3. 7.2.2.3 Output Capacitor Selection
        4. 7.2.2.4 Input Capacitor Selection
      3. 7.2.3 Application Curves
    3. 7.3 Typical Application-Li-ion Battery to 5V Boost Converter Under Normal Mode
      1. 7.3.1 Design Requirements
      2. 7.3.2 Application Curves
    4. 7.4 Power Supply Recommendations
    5. 7.5 Layout
      1. 7.5.1 Layout Guidelines
      2. 7.5.2 Layout Example
      3. 7.5.3 Thermal Information
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Third-Party Products Disclaimer
    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

6.3.7 Soft-Start Timing

After the EN pin is tied to high voltage, the TPS61299-Q1 begins to startup.

For the high input current limit is 250mA, 500mA, 1.2A and 1.9A version, at the beginning, when output voltage is lower than 0.5V, device limits the output power for the short protection. As output voltage is higher than 0.5V, 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 350mA during this stage. After the output voltage reaches close to 1.8V, the TPS61299-Q1starts to detect the output voltage configuration of the VSEL pins, then latches the configuration. The version detection time depends on the resistance at VSEL pin, the higher resistance, the longer version detection time. Eg. for 5V normal version, the TPS61299-Q1 needs approximately 170μs for version detection. After version detection, TPS61299-Q1 continues switching and output ramps up further. The internal soft-start time is approximately 1.3ms, and the output soft start time varies with the different output capacitance, load condition, and configuration conditions. The TPS61299-Q1 limits the inductor average current lower than 500mA, (input current limit to 250mA for 250mA version) when output voltage is lower than 2.5V. In this way, the soft start function reduces the inrush current during startup.

GUID-20230228-SS0I-QR9J-DDCT-2MDXBH8PP7DN-low.svg Figure 6-3 Soft-Start Timing