SLVS974F September   2009  – May 2020

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
    1.     Device Images
      1.      Simplified Schematic
      2.      Efficiency versus Output Current
  4. Revision History
  5. Pin Configuration and Functions
    1.     Pin 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 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Fixed Frequency PWM Control
      2. 7.3.2  Slope Compensation and Output Current
      3. 7.3.3  Bootstrap Voltage (Boot) and Low Dropout Operation
      4. 7.3.4  Error Amplifier
      5. 7.3.5  Voltage Reference
      6. 7.3.6  Adjusting the Output Voltage
      7. 7.3.7  Enable and Adjusting Undervoltage Lockout
      8. 7.3.8  Soft-Start Pin
      9. 7.3.9  Sequencing
      10. 7.3.10 Constant Switching Frequency and Timing Resistor (RT/CLK Pin)
      11. 7.3.11 Overcurrent Protection
      12. 7.3.12 Frequency Shift
      13. 7.3.13 Reverse Overcurrent Protection
      14. 7.3.14 Synchronize Using the RT/CLK Pin
      15. 7.3.15 Power Good (PWRGD Pin)
      16. 7.3.16 Overvoltage Transient Protection
      17. 7.3.17 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Small Signal Model for Loop Response
      2. 7.4.2 Simple Small Signal Model for Peak Current Mode Control
      3. 7.4.3 Small Signal Model for Frequency Compensation
  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  Step One: Select the Switching Frequency
        2. 8.2.2.2  Step Two: Select the Output Inductor
        3. 8.2.2.3  Step Three: Choose the Output Capacitor
        4. 8.2.2.4  Step Four: Select the Input Capacitor
        5. 8.2.2.5  Step Five: Minimum Load DC COMP Voltage
        6. 8.2.2.6  Step Six: Choose the Soft-Start Capacitor
        7. 8.2.2.7  Step Seven: Select the Bootstrap Capacitor
        8. 8.2.2.8  Step Eight: Undervoltage Lockout Threshold
        9. 8.2.2.9  Step Nine: Select Output Voltage and Feedback Resistors
          1. 8.2.2.9.1 Output Voltage Limitations
        10. 8.2.2.10 Step 10: Select Loop Compensation Components
        11. 8.2.2.11 Power Dissipation Estimate
      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 Development Support
        1. 11.1.1.1 Custom Design With WEBENCH® Tools
    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

Typical Characteristics

TPS54218 hilo_rdson_lvs946.gifFigure 1. High-Side and Low-Side On-Resistance versus Junction Temperature
TPS54218 sw_cur_tj_lvs974.gifFigure 3. High-Side Current Limit versus Junction Temperature
TPS54218 fs_rt_lvs974.gifFigure 5. Switching Frequency versus RT Resistance Low Frequency Range
TPS54218 fs_vsense.gifFigure 7. Switching Frequency versus Vsense
TPS54218 ea2_tj_lvs946.gifFigure 9. Transconductance (Soft Start) versus Junction Temperature
TPS54218 pin_cur_tj_lvs974.gifFigure 11. Pin Current versus Junction Temperature
TPS54218 D001_SLVS974.gif
Figure 13. Junction Temperature versus SS Charge Current
TPS54218 vin_tj_lvs946.gifFigure 15. Input Voltage versus Junction Temperature
TPS54218 shutdwn_vi_lvs946.gifFigure 17. Shutdown Supply Current versus Input Voltage
TPS54218 icc_vi_lvs946.gifFigure 19. Supply Current versus Input Voltage
TPS54218 radson_tj_lvs946.gifFigure 21. PWRGD On Resistance versus Junction Temperature
TPS54218 freq_temp_lvs946.gifFigure 2. Switching Frequency versus Junction Temperature
TPS54218 vrefA_tj_lvs974.gifFigure 4. Voltage Reference versus Junction Temperature
TPS54218 fs2_rt_lvs974.gifFigure 6. Switching Frequency versus RT Resistance High Frequency Range
TPS54218 ea_tj_lvs946.gifFigure 8. Transconductance versus Junction Temperature
TPS54218 en_tj_lvs946.gifFigure 10. Enable Pin Voltage versus Junction Temperature
TPS54218 pin2_cur_tj_lvs974.gifFigure 12. Pin Current versus Junction Temperature
TPS54218 ss2_tj_lvs946.gifFigure 14. Discharge Current versus Junction Temperature
TPS54218 shutdwn_tj_lvs946.gifFigure 16. Shutdown Supply Current versus Junction Temperature
TPS54218 icc_tj_lvs946.gifFigure 18. Supply Current versus Junction Temperature
TPS54218 pwrgd_tj_lvs946.gifFigure 20. PWRGD Threshold versus Junction Temperature
TPS54218 comp_v_temp_slvs946.gifFigure 22. Minimum Comp Voltage Clamp versus Junction Temperature