SLVSGW6 August   2024 TPS55287

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 I2C Timing Characteristics
    7. 5.7 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1  VCC Power Supply
      2. 6.3.2  EXTVCC Power Supply
      3. 6.3.3  Operation Mode Setting
      4. 6.3.4  Input Undervoltage Lockout
      5. 6.3.5  Enable and Programmable UVLO
      6. 6.3.6  Soft Start
      7. 6.3.7  Shutdown and Load Discharge
      8. 6.3.8  Switching Frequency
      9. 6.3.9  Switching Frequency Dithering
      10. 6.3.10 Inductor Current Limit
      11. 6.3.11 Internal Charge Path
      12. 6.3.12 Output Voltage Setting
      13. 6.3.13 Output Current Monitoring and Cable Voltage Droop Compensation
      14. 6.3.14 Output Current Limit
      15. 6.3.15 Overvoltage Protection
      16. 6.3.16 Output Short Circuit Protection
      17. 6.3.17 Thermal Shutdown
    4. 6.4 Device Functional Modes
      1. 6.4.1 PWM Mode
      2. 6.4.2 Power Save Mode
    5. 6.5 Programming
      1. 6.5.1 Data Validity
      2. 6.5.2 START and STOP Conditions
      3. 6.5.3 Byte Format
      4. 6.5.4 Acknowledge (ACK) and Not Acknowledge (NACK)
      5. 6.5.5 Target Address and Data Direction Bit
      6. 6.5.6 Single Read and Write
      7. 6.5.7 Multiread and Multiwrite
    6. 6.6 Register Maps
      1. 6.6.1 REF Register (Address = 0h, 1h)
      2. 6.6.2 IOUT_LIMIT Register (Address = 2h) [reset = 11100100h]
      3. 6.6.3 VOUT_SR Register (Address = 3h) [reset = 00000001h]
      4. 6.6.4 VOUT_FS Register (Address = 4h) [reset = 00000011h]
      5. 6.6.5 CDC Register (Address = 5h) [reset = 11100000h]
      6. 6.6.6 MODE Register (Address = 6h) [reset = 00100000h]
      7. 6.6.7 STATUS Register (Address = 7h) [reset = 00000011h]
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Switching Frequency
        2. 7.2.2.2 Output Voltage Setting
        3. 7.2.2.3 Inductor Selection
        4. 7.2.2.4 Input Capacitor
        5. 7.2.2.5 Output Capacitor
        6. 7.2.2.6 Output Current Limit
        7. 7.2.2.7 Loop Stability
      3. 7.2.3 Application Curves
  9. 8 Power Supply Recommendations
  10. 9 Layout
    1. 9.1 Layout Guidelines
    2. 9.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Third-Party Products Disclaimer
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

6.3.8 Switching Frequency

The TPS55287 uses a fixed frequency average current control scheme. The switching frequency is between 200kHz and 2.2MHz set by placing a resistor at the FSW pin. An internal amplifier holds this pin at a fixed voltage of 1V. The setting resistance is between maximum of 100kΩ and minimum of 8.4kΩ. Use Equation 3 to calculate the resistance by a given switching frequency.

Equation 3. f S W = 1000 0.05 × R F S W + 35

where

  • RFSW is the resistance at the FSW pin.

For noise-sensitive applications, the TPS55287 can be synchronized to an external clock signal applied to the DITH/SYNC pin. The duty cycle of the external clock is recommended in the range of 30% to 70%. A resistor also must be connected to the FSW pin when the TPS55287 is switching by the external clock. The external clock frequency at the DITH/SYNC pin must have lower than 0.4V low level voltage and must be within ±30% of the corresponding frequency set by the resistor. Figure 6-3 is a recommended configuration.

TPS55287 External Clock Configuration Figure 6-3 External Clock Configuration