SLVS992D September   2009  – April 2019 TPS61093

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Shutdown and Load Discharge
      2. 7.3.2 Overload and Overvoltage Protection
      3. 7.3.3 UVLO
      4. 7.3.4 Thermal Shutdown
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 15 V Output Boost Converter
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Custom Design With WEBENCH® Tools
          2. 8.2.1.2.2 Output Program
          3. 8.2.1.2.3 Without Isolation FET
          4. 8.2.1.2.4 Start-Up
          5. 8.2.1.2.5 Switch Duty Cycle
          6. 8.2.1.2.6 Inductor Selection
          7. 8.2.1.2.7 Input and Output Capacitor Selection
          8. 8.2.1.2.8 Small Signal Stability
        3. 8.2.1.3 Application Curves
      2. 8.2.2 10 V, –10 V Dual Output Boost Converter
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
        3. 8.2.2.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
      2. 11.1.2 Development Support
        1. 11.1.2.1 Custom Design With WEBENCH® Tools
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

8.2.1.2.5 Switch Duty Cycle

The maximum switch duty cycle (D) of the TPS61093 is 90% (minimum). The duty cycle of a boost converter under continuous conduction mode (CCM) is given by:

Equation 3. TPS61093 eq1_d_lvs992.gif

The duty cycle must be lower than the specification in the application; otherwise the output voltage cannot be regulated.

The TPS61093 has a minimum ON pulse width once the PWM switch is turned on. As the output current drops, the device enters discontinuous conduction mode (DCM). If the output current drops extremely low, causing the ON time to be reduced to the minimum ON time, the TPS61093 enters pulse-skipping mode. In this mode, the device keeps the power switch off for several switching cycles to keep the output voltage in regulation. See Figure 14. The output current when the IC enters skipping mode is calculated with Equation 4.

Equation 4. TPS61093 eq2_iout_lvs992.gif

where

  • Tmin_on = Minimum ON pulse width specification (typically 65-ns);
  • L = Selected inductor value;
  • fSW = Converter switching frequency (typically 1.2-MHz)