SLUS772G March   2008  – June 2020 TPS40210 , TPS40211

PRODUCTION DATA  

  1. Features
  2. Applications
  3. Description
  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  Soft Start
      2. 7.3.2  BP Regulator
      3. 7.3.3  Shutdown (DIS/ EN Pin)
      4. 7.3.4  Minimum On-Time and Off-Time Considerations
      5. 7.3.5  Setting the Oscillator Frequency
      6. 7.3.6  Synchronizing the Oscillator
      7. 7.3.7  Current Sense and Overcurrent
      8. 7.3.8  Current Sense and Subharmonic Instability
      9. 7.3.9  Current Sense Filtering
      10. 7.3.10 Control Loop Considerations
      11. 7.3.11 Gate Drive Circuit
      12. 7.3.12 TPS40211
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operation Near Minimum Input Voltage
      2. 7.4.2 Operation With DIS/ EN Pin
  8. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 12-V to 24-V Nonsynchronous Boost Regulator
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1  Custom Design with WEBENCH Tools
          2. 8.2.1.2.2  Duty Cycle Estimation
          3. 8.2.1.2.3  Inductor Selection
          4. 8.2.1.2.4  Rectifier Diode Selection
          5. 8.2.1.2.5  Output Capacitor Selection
          6. 8.2.1.2.6  Input Capacitor Selection
          7. 8.2.1.2.7  Current Sense and Current Limit
          8. 8.2.1.2.8  Current Sense Filter
          9. 8.2.1.2.9  Switching MOSFET Selection
          10. 8.2.1.2.10 Feedback Divider Resistors
          11. 8.2.1.2.11 Error Amplifier Compensation
          12. 8.2.1.2.12 RC Oscillator
          13. 8.2.1.2.13 Soft-Start Capacitor
          14. 8.2.1.2.14 Regulator Bypass
          15. 8.2.1.2.15 Bill of Materials
        3. 8.2.1.3 Application Curves
      2. 8.2.2 12-V Input, 700-mA LED Driver, Up to 35-V LED String
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
  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.      65
      3. 11.1.2 Related Devices
      4. 11.1.3 Development Support
        1. 11.1.3.1 Custom Design with WEBENCH Tools
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Related Links
    4. 11.4 Receiving Notification of Documentation Updates
    5. 11.5 Support Resources
    6. 11.6 Trademarks
    7. 11.7 Electrostatic Discharge Caution
    8. 11.8 Glossary
  12. 12Mechanical, Packaging, and Orderable Information
    1.     78

Gate Drive Circuit

Some applications benefit from the addition of a resistor connected between the GDRV pin and the gate of the switching MOSFET. In applications that have particularly stringent load regulation (under 0.75%) requirements and operate from input voltages above 5 V, or are sensitive to pulse jitter in the discontinuous conduction region, this resistor is recommended. The recommended starting point for the value of this resistor can be calculated from Equation 30.

Equation 30. GUID-51E116EC-C7BA-4792-A555-8582CEB850EC-low.gif

where

  • QG is the MOSFET total gate charge at 8 V, VGS in nC
  • RG is the suggested starting point gate resistance in Ω
GUID-C5C57EA1-3B26-4A99-8BF3-316E76C88036-low.gifFigure 7-9 Gate Drive Resistor