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

7.3.4 Ramp Signal

The TPS53219A adds a ramp signal to the 0.6-V reference in order to improve jitter performance. As described in Small Signal Model, the feedback voltage is compared with the reference information to keep the output voltage in regulation. By adding a small ramp signal to the reference, the S/N ratio at the onset of a new switching cycle is improved. Therefore the operation becomes less jittery and more stable. The ramp signal is controlled to start with –7 mV at the beginning of an on-cycle and becomes 0 mV at the end of an off-cycle in steady-state.

During skip mode operation, when the switching frequency is lower than 70% of the nominal frequency (because of longer OFF-time), the ramp signal exceeds 0 mV at the end of the OFF-time but is clamped at 3 mV to minimize DC offset.