SLUSFG9A April   2024  – June 2024 TPS561243 , TPS561246

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Adaptive On-Time Control and PWM Operation
      2. 6.3.2 Eco-mode Control
      3. 6.3.3 Soft Start and Prebiased Soft Start
      4. 6.3.4 Large Duty Operation
      5. 6.3.5 Current Protection
      6. 6.3.6 Enable Circuit
      7. 6.3.7 Undervoltage Lockout (UVLO) Protection
      8. 6.3.8 Thermal Shutdown
    4. 6.4 Device Functional Modes
      1. 6.4.1 Eco-mode Operation
      2. 6.4.2 FCCM Mode Operation
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Custom Design With WEBENCH® Tools
        2. 7.2.2.2 Output Voltage Resistors Selection
        3. 7.2.2.3 Output Filter Selection
        4. 7.2.2.4 Input Capacitor Selection
        5. 7.2.2.5 Bootstrap Capacitor Selection
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
        1. 8.1.1.1 Custom Design With WEBENCH® Tools
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

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

6.3.1 Adaptive On-Time Control and PWM Operation

The TPS56124x implements D-CAP3 control scheme that supports adaptive on-time pulse width modulation (PWM) control with an internal compensation circuit for pseudo-fixed frequency and low external component count configuration, with both low-ESR and ceramic output capacitors. The D-CAP3 control scheme is stable even with virtually no ripple at the output. The TPS56124x also includes an error amplifier that makes the output voltage very accurate.

At the beginning of each cycle, the high-side MOSFET is turned on. This MOSFET is turned off after the internal one shot timer expires. This one shot duration is set proportional to the output voltage, VO, and inversely proportional to the converter input voltage, VIN, to maintain a pseudo-fixed frequency over the input voltage range, hence called adaptive on-time control. The one-shot timer is reset and the high-side MOSFET is turned on again when the feedback voltage falls below the reference voltage. An internal ramp is added to reference voltage to simulate output ripple, eliminating the need for ESR induced output ripple from D-CAP3 control scheme.