SLVSB76B August   2012  – August 2019 TPS63036

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application Schematic
      2.      Efficiency vs Output Current
  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 Device Enable
      2. 7.3.2 Overvoltage Protection
      3. 7.3.3 Undervoltage Lockout
      4. 7.3.4 Overtemperature Protection
    4. 7.4 Device Functional Modes
      1. 7.4.1 Soft-Start and Short Circuit Protection
      2. 7.4.2 Buck-Boost Operation
      3. 7.4.3 Control Loop
      4. 7.4.4 Power-Save Mode and Synchronization
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Inductor Selection
        2. 8.2.2.2 Capacitor Selection
          1. 8.2.2.2.1 Input Capacitor
          2. 8.2.2.2.2 Output Capacitor
        3. 8.2.2.3 Setting the Output Voltage
        4. 8.2.2.4 Current Limit
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Considerations
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

8.2.2.4 Current Limit

To protect the device and the application, the average input current is limited internally on the IC. At nominal operating conditions, this current limit is constant. The current limit value can be found in the Electrical Characteristics table. The current limit varies depending on the input voltage. A curve of the input current varying with the input voltage is shown in Figure 5 and Figure 6 respectively showing the minimum and the maximum current limit expected depending on input and output voltage.

Given the average input current in Figure 5 is then possible to calculate the output current reached in boost mode using Equation 5 and Equation 6 and in buck mode using Equation 7 and Equation 8.

Equation 5. TPS63036 q1_boost_lvsa92.gif
Equation 6. TPS63036 q2_MaxOutCur_lvsa92.gif
Equation 7. TPS63036 q3_buck_lvsa92.gif
Equation 8. TPS63036 q4_MaxOutBuck_lvsa92[1].gif

where

  • η = Estimated converter efficiency (use the number from the efficiency curves or 0.80 as an assumption)
  • f = Converter switching frequency (typical 2 MHz)
  • L = Selected inductor value
  • ISW = Minimum average input current (Figure 5)