SNVS902A October   2012  – October 2015 TPS92640 , TPS92641

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 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  Controlled On-Time Architecture
      2. 7.3.2  Switching Frequency
      3. 7.3.3  Average LED Current
      4. 7.3.4  Analog Dimming and True-Zero Operation
      5. 7.3.5  Undervoltage Lockout (UVLO)
      6. 7.3.6  PWM Dimming Using the UDIM Pin
      7. 7.3.7  External Shunt FET PWM Dimming
      8. 7.3.8  VCC Regulation and Start-up
      9. 7.3.9  Precision Reference
      10. 7.3.10 Control Loop Compensation
      11. 7.3.11 Overcurrent Protection
      12. 7.3.12 Overvoltage Protection (OVP)
      13. 7.3.13 Boot Undervoltage Lockout (UVLO)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Low Power Shutdown Using the UDIM Pin
      2. 7.4.2 Thermal Shutdown
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Switching Frequency
      2. 8.1.2 LED Ripple Current
      3. 8.1.3 Buck Converters Without Output Capacitor
      4. 8.1.4 Input Capacitor
      5. 8.1.5 NFETs
    2. 8.2 Typical Applications
      1. 8.2.1 TPS92640: Design Procedure
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Set Output Voltage Feedback Ratio
          2. 8.2.1.2.2 Set Switching Frequency
          3. 8.2.1.2.3 Set Average LED Current
          4. 8.2.1.2.4 Set Inductor Ripple Current
          5. 8.2.1.2.5 Set LED Ripple Current and Determine Output Capacitance, COUT
          6. 8.2.1.2.6 Choose N-Channel MOSFETs
          7. 8.2.1.2.7 Choose Input Capacitance
          8. 8.2.1.2.8 Set the Turnon Voltage and Undervoltage Lockout Hysteresis
      2. 8.2.2 TPS92640 - PWM Dimming Application
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
          1. 8.2.2.2.1 Calculate Operating Points
          2. 8.2.2.2.2 Output Voltage Feedback
          3. 8.2.2.2.3 Switching Frequency
          4. 8.2.2.2.4 Set the Feedback Reference and LED Current
          5. 8.2.2.2.5 Calculate the Inductor Value
          6. 8.2.2.2.6 Calculate the Output Capacitor Value
          7. 8.2.2.2.7 Calculate the MOSFET Parameters
          8. 8.2.2.2.8 Calculate the Minimum Input Capacitance
          9. 8.2.2.2.9 Undervoltage Lockout and Hysteresis
        3. 8.2.2.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 EMI and Noise Considerations
  11. 11Device and Documentation Support
    1. 11.1 Related Links
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

12 Mechanical, Packaging, and Orderable Information

The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of this document. For browser-based versions of this data sheet, refer to the left-hand navigation.