TIDUD32A June   2017  – January 2023

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
    1. 1.1 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Highlighted Products
      1. 2.2.1 TPS82130
    3. 2.3 Design Considerations
      1. 2.3.1 Inverting Buck-Boost Topology Concept
      2. 2.3.2 VIN and VOUT Range
      3. 2.3.3 Maximum Output Current
        1. 2.3.3.1 Thermal Limits
        2. 2.3.3.2 Stability Limits and Output Capacitor Selection
      4. 2.3.4 Design Precautions
      5. 2.3.5 Enable Pin Configuration
      6. 2.3.6 Power Good Pin Configuration
      7. 2.3.7 Discharging Output Voltage
      8. 2.3.8 Adjustable Soft-Start Time
      9. 2.3.9 Input Capacitor Selection
  8. 3Getting Started Hardware
  9. 4Testing and Results
  10. 5Design Files
    1. 5.1 Schematics
    2. 5.2 Bill of Materials
    3. 5.3 PCB Layout Recommendations
      1. 5.3.1 Layout Prints
    4. 5.4 Gerber Files
    5. 5.5 Assembly Drawings
  11. 6Related Documentation
  12. 7Trademarks
  13. 8Revision History

2.3.3 Maximum Output Current

In the inverting buck-boost topology, the maximum output current is reduced as compared to the buck topology. This reduction is a result of the peak inductor current being higher, as calculated in Equation 4. With a power module, there are additional thermal limits arising from the small size of the power module itself. Finally, there are further limits on the maximum output current that occur from stability due to the right-half plane zero, which occurs in the inverting buck-boost topology. Figure 4-1 shows the maximum output current based on temperature rise and stability for the TIDA-01457 design. The current limit for the TPS82130 device occurs above all curves in Figure 4-1 and therefore does not limit the maximum output current more than thermal or stability limits. The current limit itself still operates to limit the peak inductor current.