SLVSCW4C April   2016  – June 2026 TPS560200-Q1

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 PWM Operation
      2. 6.3.2 PWM Frequency and Adaptive On-Time Control
      3. 6.3.3 Advanced Auto-Skip Eco-mode Control
      4. 6.3.4 Soft Start and Prebiased Soft Start
      5. 6.3.5 Current Protection
      6. 6.3.6 Thermal Shutdown
    4. 6.4 Device Functional Modes
      1. 6.4.1 Normal Operation
      2. 6.4.2 Eco-mode Operation
      3. 6.4.3 Standby 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 Output Voltage Resistors Selection
        2. 7.2.2.2 Output Filter Selection
        3. 7.2.2.3 Input 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 Receiving Notification of Documentation Updates
    2. 8.2 Support Resources
    3. 8.3 Trademarks
    4. 8.4 Electrostatic Discharge Caution
    5. 8.5 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

6.3.4 Soft Start and Prebiased Soft Start

The TPS560200-Q1 has an internal 2ms soft start. When the EN pin becomes high, internal soft-start function begins ramping up the reference voltage to the PWM comparator.

The TPS560200-Q1 contains a unique circuit to prevent current from being pulled from the output during start-up if the output is prebiased. When the soft start commands a voltage higher than the prebias level (internal soft start becomes greater than feedback voltage VVSENSE), the controller slowly activates synchronous rectification by starting the first low-side FET gate driver pulses with a narrow on-time. It then increments that on-time on a cycle-by-cycle basis until coinciding with the time dictated by (1D), where D is the duty cycle of the converter. This scheme prevents the initial sinking of the prebias output, and ensure that the out voltage (VOUT) starts and ramps up smoothly into regulation and the control loop is given time to transition from prebiased start-up to normal mode operation.