SLUSFC7 july   2023 UCC27444

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 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 Switching Characteristics
    7. 6.7 Timing Diagrams
    8. 6.8 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Operating Supply Current
      2. 7.3.2 Input Stage
      3. 7.3.3 Enable Function
      4. 7.3.4 Output Stage
      5. 7.3.5 Low Propagation Delays and Tightly Matched Outputs
    4. 7.4 Device Functional Modes
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 VDD and Power On Reset
        2. 8.2.2.2 Drive Current and Power Dissipation
      3. 8.2.3 Application Curves
  10. 9 Power Supply Recommendations
  11. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Considerations
  12. 11Device and Documentation Support
    1. 11.1 Third-Party Products Disclaimer
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.3 Enable Function

The enable function is an extremely beneficial feature in gate driver devices, especially for certain applications such as synchronous rectification where the driver outputs are disabled in light-load conditions to prevent negative current circulation and to improve light-load efficiency.

The UCC27444 device is equipped with independent enable pins (ENx) for exclusive control of each driver channel operation. The enable pins are based on a non-inverting configuration (active-high operation). Thus, when ENx pins are driven high, the drivers are enabled and when ENx pins are driven low, the driver outputs are disabled. Similar to the input pins, the enable pins are also based on a TTL compatible threshold logic that is independent of the supply voltage and are effectively controlled using logic signals from 3.3-V or 5-V controllers. The ENx pins are internally pulled up to VDD using pullup resistors, as a result of which the outputs of the device are enabled in the default state. Hence even if the ENx pins are left floating the driver output is enabled. Essentially, this floating allows the UCC27444 device to be pin-to-pin compatible with TI’s previous generation of drivers (UCC27324, UCC27424, UCC27524), where Pin 1 and Pin 8 are either ENx or N/C pins.