SLUS504I September   2002  – November 2023 UCC27321 , UCC27322 , UCC37321 , UCC37322

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Description (continued)
  6. 5 Related Products
  7. 6 Pin Configuration and Functions
  8. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Switching Characteristics
    7. 7.7 Power Dissipation Ratings
    8. 7.8 Typical Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Input Stage
      2. 8.3.2 Output Stage
      3. 8.3.3 Source and Sink Capabilities during Miller Plateau
      4. 8.3.4 Enable
    4. 8.4 Device Functional Modes
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Input-to-Output Configuration
        2. 9.2.2.2 Input Threshold Type
        3. 9.2.2.3 VDD Bias Supply Voltage
        4. 9.2.2.4 Peak Source and Sink Currents
        5. 9.2.2.5 Enable and Disable Function
        6. 9.2.2.6 Propagation Delay
        7. 9.2.2.7 Power Dissipation
      3. 9.2.3 Application Curves
  11. 10Power Supply Recommendations
    1.     40
  12. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Thermal Considerations
  13. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Support Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  14. 13Revision History
  15. 14Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • D|8
  • P|8
  • DGN|8
Thermal pad, mechanical data (Package|Pins)
Orderable Information

11.3 Thermal Considerations

The useful range of a driver is greatly affected by the drive power requirements of the load and the thermal characteristics of the device package. For a power driver to be useful over a particular temperature range the package must allow for the efficient removal of the heat produced while keeping the junction temperature within rated limits. The UCC3732x family of drivers is available in three different packages to cover a range of application requirements.

As shown in the power dissipation rating table, the 8-pin SOIC (D) and 8-pin PDIP (P) packages each have a power rating of around 0.5 W with TA = 70°C. This limit is imposed in conjunction with the power derating factor also given in the table. The power dissipation in our earlier example is 0.432 W with a 10-nF load, 12 VDD, switched at 300 kHz. Thus, only one load of this size could be driven using the D or P package. The difficulties with heat removal limit the drive available in the D or P packages.

The 8-pin MSOP PowerPAD (DGN) package significantly relieves this concern by offering an effective means of removing the heat from the semiconductor junction. As illustrated in Reference 3, the PowerPAD packages offer a leadframe die pad that is exposed at the base of the package. This pad is soldered to the copper on the PC board directly underneath the device package, reducing the θjc down to 4.7°C/W. Data is presented in Reference 3 to show that the power dissipation can be quadrupled in the PowerPAD configuration when compared to the standard packages. The PC board must be designed with thermal lands and thermal vias to complete the heat removal subsystem, as summarized in Reference 4 .This allows a significant improvement in heatsinking over that available in theDor P packages, and is shown to more than double the power capability of the D and P packages.

The PowerPAD is not directly connected to any leads of the package. However, it is electrically and thermally connected to the substrate which is the ground of the device.