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

6.3.6 Enable Circuit

The EN pin controls the turn-on and turn-off of the device. When the EN pin voltage is above the turn-on threshold, the device starts switching. When the EN pin voltage falls below the turn-off threshold, the device stops switching. The default status is low because there is a 1uA pulldown current in internal IC.

EN can be controlled by a typical resistor divider circuit from Vin or by a voltage of lower than 5.5V.

The TPS56124x also allows EN to connect to Vin with a pullup resistor only. TI suggests the value of the pullup resistor be 100kohm as EN voltage is clamped by a Zener diode and this Zener diode is not allowed to go through large current. The pullup resistor R1 is not allowed to be smaller than 80kohm, and TI suggests R1 also not be too large to avoid EN not being able to turn on. The recommended value range for the pullup resistor R1 is 80kohm to 3Mohm and 100kohm is the best recommended choice.

TPS561243 TPS561246 EN Block CircuitFigure 6-1 EN Block Circuit