SLUSDG2 October   2018 TPS92515AHV-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Simplified Buck LED Driver Application
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  General Operation
      2. 8.3.2  Current Sense Comparator
      3. 8.3.3  OFF Timer
      4. 8.3.4  OFF-Timer, Shunt FET Dimming or Shunted Output Condition
      5. 8.3.5  Internal N-channel MOSFET
        1. 8.3.5.1 Drop-Out
      6. 8.3.6  VCC Internal Regulator and Undervoltage Lockout (UVLO)
      7. 8.3.7  Analog Adjust Input
        1. 8.3.7.1 IADJ Pin Clamp
        2. 8.3.7.2 IADJ Pin Clamp Characteristic
        3. 8.3.7.3 Analog Adjust (IADJ Pin) Control Methods
        4. 8.3.7.4 IADJ Control Method Notes
      8. 8.3.8  Thermal Protection
        1. 8.3.8.1 Maximum Output Current and Junction Temperature
      9. 8.3.9  Junction Temperature Relative Estimation
      10. 8.3.10 BOOT and BOOT UVLO
        1. 8.3.10.1 Start-Up, BOOT-UVLO and Pre-Charged Condition
      11. 8.3.11 PWM (UVLO and Enable)
        1. 8.3.11.1 Using PWM for UVLO (Undervoltage Lockout) Protection
          1. 8.3.11.1.1 UVLO Programming Resistors
        2. 8.3.11.2 Using PWM for Digitally Controlled Enable
        3. 8.3.11.3 UVLO: VIN, VCC and BOOT UVLO
        4. 8.3.11.4 Analog and PWM Dimming - Normalized Results and Comparison
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 General Design Procedure
        1. 9.2.1.1 Calculating Duty Cycle
        2. 9.2.1.2 Calculate OFF-Time Estimate
        3. 9.2.1.3 Calculate OFF-Time Resistor ROFF
        4. 9.2.1.4 Calculate the Minimum Inductance Value
        5. 9.2.1.5 Calculate the Sense Resistance
        6. 9.2.1.6 Calculate Input Capacitance
        7. 9.2.1.7 Calculate Output Capacitance
      2. 9.2.2 Design Requirements
      3. 9.2.3 Detailed Design Procedure
        1. 9.2.3.1 Calculating Duty Cycle
        2. 9.2.3.2 Calculate OFF-Time Estimate
        3. 9.2.3.3 Calculate OFF-Time Resistor ROFF
        4. 9.2.3.4 Calculate the Inductance Value
        5. 9.2.3.5 Calculate the Sense Resistance
        6. 9.2.3.6 Calculate Input Capacitance
        7. 9.2.3.7 Verify Peak Current for Inductor Selection
        8. 9.2.3.8 Calculate Output Capacitance
        9. 9.2.3.9 Calculate UVLO Resistance Values
      4. 9.2.4 Application Curves
    3. 9.3 Dos and Don'ts
  10. 10Power Supply Recommendations
    1. 10.1 Input Source Direct from Battery
    2. 10.2 Input Source from a Boost Stage
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
        1. 12.1.1.1 Related Links
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.10.1 Start-Up, BOOT-UVLO and Pre-Charged Condition

If a pre-charge condition occurs (a voltage exists on the output at turn-on) a resulting undervoltage lockout of the BOOT pin activates an internal, 5-mA (typical) pulldown. The pulldown reduces the time required to bring the output voltage low enough to charge the BOOT capacitor and begin operation. The device activates this strong pulldown any time undervoltage lockout of the BOOT pin occurs. However, in most situations the diode turn-on does most of the work to lower the switch node voltage. The pulldown does not act as a synchronous FET.

TPS92515AHV-Q1 BOOT_Pulldowns.gifFigure 25. BOOT and PWM Pull-Downs