SLRS076B August   2022  – September 2024 ULN2803C

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 Switching Characteristics
    7. 5.7 Typical Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
    4. 7.4 Device Functional Modes
      1. 7.4.1 Inductive Load Drive
      2. 7.4.2 Resistive Load Drive
  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 Drive Current
        2. 8.2.2.2 Output Low Voltage
        3. 8.2.2.3 Power Dissipation and Temperature
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

8.2.2.3 Power Dissipation and Temperature

The number of coils driven is dependent on the coil current and on-chip power dissipation. To determine the number of coils possible, use Equation 2 to calculate ULN2803C on-chip power dissipation PD.

Equation 2. ULN2803C

where

  • N is the number of channels active together.
  • VOLi is the OUTi pin voltage for the load current ILi. This is the same as VCE(SAT).

To ensure the reliability of ULN2803C and the system, the on-chip power dissipation must be lower that or equal to the maximum allowable power dissipation (PD) dictated by Equation 3.

Equation 3. ULN2803C

where

  • TJ(MAX) is the target maximum junction temperature.
  • TA is the operating ambient temperature.
  • θJA is the package junction to ambient thermal resistance.

TI recommends to limit the ULN2803C IC die junction temperature to < 125°C. The IC junction temperature is directly proportional to the on-chip power dissipation.