SLVSF01B November   2018  – December 2020 TPS55288

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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 I2C Timing Characteristics
    7. 6.7 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  VCC Power Supply
      2. 7.3.2  Operation Mode Setting
      3. 7.3.3  Input Undervoltage Lockout
      4. 7.3.4  Enable and Programmable UVLO
      5. 7.3.5  Soft Start
      6. 7.3.6  Shutdown and Load Discharge
      7. 7.3.7  Switching Frequency
      8. 7.3.8  Switching Frequency Dithering
      9. 7.3.9  Inductor Current Limit
      10. 7.3.10 Internal Charge Path
      11. 7.3.11 Output Voltage Setting
      12. 7.3.12 Output Current Monitoring and Cable Voltage Droop Compensation
      13. 7.3.13 Integrated Gate Drivers
      14. 7.3.14 Output Current Limit
      15. 7.3.15 Overvoltage Protection
      16. 7.3.16 Output Short Circuit Protection
      17. 7.3.17 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 PWM Mode
      2. 7.4.2 Power Save Mode
    5. 7.5 I2C Serial Interface
      1. 7.5.1 Data Validity
      2. 7.5.2 START and STOP Conditions
      3. 7.5.3 Byte Format
      4. 7.5.4 Acknowledge (ACK) and Not Acknowledge (NACK)
      5. 7.5.5 Slave Address and Data Direction Bit
      6. 7.5.6 Single Read and Write
      7. 7.5.7 Multi-Read and Multi-Write
    6. 7.6 Register Maps
      1. 7.6.1 REF Register (Address = 0h, 1h) [reset = 11010010h, 00000000h]
      2. 7.6.2 IOUT_LIMIT Register (Address = 2h) [reset = 11100100h]
      3. 7.6.3 VOUT_SR Register (Address = 3h) [reset = 00000001h]
      4. 7.6.4 VOUT_FS Register (Address = 4h) [reset = 00000011h]
      5. 7.6.5 CDC Register (Address = 5h) [reset = 11100000h]
      6. 7.6.6 MODE Register (Address = 6h) [reset = 00100000h]
      7. 7.6.7 STATUS Register (Address = 7h) [reset = 00000011h]
      8. 7.6.8 Register Summary
  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 USB PD Power Supply Detailed Design Procedure
        1. 8.2.2.1 Switching Frequency
        2. 8.2.2.2 Output Voltage Setting
        3. 8.2.2.3 Inductor Selection
        4. 8.2.2.4 Input Capacitor
        5. 8.2.2.5 Output Capacitor
        6. 8.2.2.6 Output Current Limit
        7. 8.2.2.7 Loop Stability
      3. 8.2.3 Application Curves
  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. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support 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

7.3.9 Inductor Current Limit

The TPS55288 implements both peak current and average inductor current limit by a resistor connected to the ILIM pin. The average current mode control loop uses the current sense information at the high-side MOSFET of the boost leg to clamp the maximum average inductor current to 16.5 A (typical) when the resistor is 20 kΩ. Use large resistance to get smaller average inductor current limit. Use Equation 5 to calculate the resistance for a desired average inductor current limit.

Equation 5. GUID-1494CF74-4230-40E5-8415-1155E03E9328-low.gif

where

  • IAVG_LIMIT is the average inductor current limit
  • RILIM is the resistance (Ω) between the ILIM pin and analog ground

Besides the average current limit, a peak current limit protection is implemented during transient to protect the device against over current condition beyond the capability of the device.