SLVSGA9A March   2022  – August 2022 TPS55289

PRODUCTION DATA  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
  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. 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  EXTVCC Power Supply
      3. 7.3.3  Operation Mode Setting
      4. 7.3.4  Input Undervoltage Lockout
      5. 7.3.5  Enable and Programmable UVLO
      6. 7.3.6  Soft Start
      7. 7.3.7  Shutdown and Load Discharge
      8. 7.3.8  Switching Frequency
      9. 7.3.9  Switching Frequency Dithering
      10. 7.3.10 Inductor Current Limit
      11. 7.3.11 Internal Charge Path
      12. 7.3.12 Output Voltage Setting
      13. 7.3.13 Output Current Monitoring and Cable Voltage Droop Compensation
      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 Programming
      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 Target Address and Data Direction Bit
      6. 7.5.6 Single Read and Write
      7. 7.5.7 Multiread and Multiwrite
    6. 7.6 Register Maps
      1. 7.6.1 REF Register (Address = 0h, 1h)
      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. 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 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. 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

Output Current Limit

The output current limit is implemented by placing a current sense resistor between the ISP and ISN pins along with setting a limit voltage between the ISP pin and the ISN pin through register 02h. The maximum value of the limit voltage between the ISP and ISN pins is 63.5 mV. The default limit voltage is 50 mV. The current sense resistor between the ISP and ISN pins should be selected to ensure that the output current limit is set high enough for output. The output current limit setting resistor is given by Equation 18.

Equation 18. GUID-ED811B13-3DAD-48DC-B139-B04FF7EE10C2-low.gif

where

  • VSNS is the current limit setting voltage between the ISP and ISN pins.
  • IOUT_LIMIT is the desired output current limit.

Because the power dissipation is large, make sure the current sense resistor has enough power dissipation capability with a large package.