SLVS873F June   2015  – September 2021 TPS61098 , TPS610981 , TPS610982 , TPS610985 , TPS610986 , TPS610987

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 Diagrams
    3. 8.3 Feature Description
      1. 8.3.1 Boost Controller Operation
      2. 8.3.2 Pass-Through Operation
      3. 8.3.3 LDO / Load Switch Operation
      4. 8.3.4 Start Up and Power Down
      5. 8.3.5 Over Load Protection
      6. 8.3.6 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Operation Modes by MODE Pin
        1. 8.4.1.1 Active Mode
        2. 8.4.1.2 Low Power Mode
      2. 8.4.2 Burst Mode Operation under Light Load Condition
      3. 8.4.3 Pass-Through Mode Operation
  9. 9 Applications and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 VMAIN to Power MCU and VSUB to Power Subsystem
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Device Choice
          2. 9.2.1.2.2 Maximum Output Current
          3. 9.2.1.2.3 Inductor Selection
          4. 9.2.1.2.4 Capacitor Selection
          5. 9.2.1.2.5 Control Sequence
        3. 9.2.1.3 Application Curves
      2. 9.2.2 VMAIN to Power the System in Low Power Mode
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Curves
      3. 9.2.3 VSUB to Power the System in Active Mode
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
        3. 9.2.3.3 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 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

8.3.1 Boost Controller Operation

The TPS61098x boost converter is controlled by a hysteretic current mode controller. This controller regulates the output voltage by keeping the inductor ripple current constant in the range of 100 mA and adjusting the offset of this inductor current depending on the output load. Since the input voltage, output voltage and inductor value all affect the rising and falling slopes of inductor ripple current, the switching frequency is not fixed and is decided by the operation condition. If the required average input current is lower than the average inductor current defined by this constant ripple, the inductor current goes discontinuous to keep the efficiency high under light load conditions. Figure 8-1 illustrates the hysteretic current operation. If the load is reduced further, the boost converter enters into Burst mode. In Burst mode, the boost converter ramps up the output voltage with several pulses and it stops operating once the output voltage exceeds a set threshold, and then it goes into a sleep status and consumes less quiescent current. It resumes switching when the output voltage is below the set threshold. It exits the Burst mode when the output current can no longer be supported in this mode. Refer to Figure 8-2 for Burst mode operation details.

To achieve high efficiency, the power stage is realized as a synchronous boost topology. The output voltage V(MAIN) is monitored via an internal feedback network which is connected to the voltage error amplifier. To regulate the output voltage, the voltage error amplifier compares this feedback voltage to the internal voltage reference and adjusts the required offset of the inductor current accordingly.

GUID-0EFE7A7D-AF24-4187-849F-5B5F7E98E35A-low.gifFigure 8-1 Hysteretic Current Operation
GUID-25A6C85D-90EF-464A-BD09-DB8F648F39B1-low.gifFigure 8-2 Burst Mode Operation