SLUSAU4B DECEMBER   2011  – February 2019 TPS53219A

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin 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  Enable and Soft-Start
      2. 7.3.2  Adaptive ON-Time D-CAP Control and Frequency Selection
      3. 7.3.3  Small Signal Model
      4. 7.3.4  Ramp Signal
      5. 7.3.5  Adaptive Zero Crossing
      6. 7.3.6  Output Discharge Control
      7. 7.3.7  Low-Side Driver
      8. 7.3.8  High-Side Driver
      9. 7.3.9  Power Good
      10. 7.3.10 Current Sense and Overcurrent Protection
      11. 7.3.11 Overvoltage and Undervoltage Protection
      12. 7.3.12 UVLO Protection
      13. 7.3.13 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Light Load Condition in Auto-Skip Operation
      2. 7.4.2 Forced Continuous Conduction Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Typical Application With Power Block
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 External Components Selection
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Typical Application With Ceramic Output Capacitors
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
          1. 8.2.2.2.1 External Parts Selection With All Ceramic Output Capacitors
        3. 8.2.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    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

8.2.1.2.1 External Components Selection

Selecting external components is a simple process using D-CAP Mode.

  1. Choose the inductor

    2. The inductance should be determined to give the ripple current of approximately ¼ to ½ of maximum output current. Larger ripple current increases output ripple voltage and improves the signal-to-noise ratio and helps stable operation.

    Equation 9. TPS53219A q_l1_lusaa8.gif

    The inductor also requires a low DCR to achieve good efficiency. It also requires enough room above the peak inductor current before saturation. The peak inductor current can be estimated in Equation 10.

    Equation 10. TPS53219A q_iindpeak_lusaa8.gif
  2. Choose the output capacitor

    3. When organic semiconductor capacitors or specialty polymer capacitors are used, for loop stability, capacitance and ESR should satisfy Equation 2. For jitter performance, Equation 11 is a good starting point to determine ESR.

    Equation 11. TPS53219A q_esr_lusaa8.gif

    where

    • D is the duty factor
    • the required output ripple slope is approximately 10 mV per tSW (switching period) in terms of VFB terminal voltage
  3. Determine the value of R1 and R2

    4. The output voltage is programmed by the voltage-divider resistor, R1 and R2 shown in Figure 17. R1 is connected between the VFB pin and the output, and R2 is connected between the VFB pin and GND. Recommended R2 value is between 10 kΩ and 20 kΩ. Determine R1 using Equation 12.

    Equation 12. TPS53219A q_r1_lusaa8.gif