SLRS059B April   2012  – June  2015 ULN2003LV


  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
  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 Dissipation Ratings
    8. 6.8 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 TTL and Other Logic Inputs
      2. 7.3.2 Input RC Snubber
      3. 7.3.3 High-Impedance Input Drivers
    4. 7.4 Device Functional Modes
  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
      3. 8.2.3 Application Curve
    3. 8.3 System Examples
      1. 8.3.1 Max Supply Selector
      2. 8.3.2 Constant Current Generation
      3. 8.3.3 Unipolar Stepper Motor Driver
      4. 8.3.4 NOR Logic Driver
      5. 8.3.5 1.8-V Relay Driver
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 On-Chip Power Dissipation
    4. 10.4 Thermal Considerations
      1. 10.4.1 Improving Package Thermal Performance
  11. 11Device and Documentation Support
    1. 11.1 Community Resources
    2. 11.2 Trademarks
    3. 11.3 Electrostatic Discharge Caution
    4. 11.4 Glossary
  12. 12Mechanical, Packaging, and Orderable Information



10 Layout

10.1 Layout Guidelines

Thin traces can be used on the input due to the low current logic that is typically used to drive ULN2003LV. Take care to separate the input channels as much as possible, as to eliminate cross-talk. Thick traces are recommended for the output, in order to drive high currents that may be needed. Wire thickness can be determined by the trace material's current density and desired drive current. Since all of the channels currents return to a common ground, it is best to size that trace width to be very wide. Some applications require up to 1 A.

10.2 Layout Example

ULN2003LV uln2003lvlayout.gifFigure 14. Layout Example Recommendation

10.3 On-Chip Power Dissipation

Use Equation 3 to calculate ULN2003LV on-chip power dissipation PD:

Equation 3. ULN2003LV eq1_lrs059.gif


  • N is the number of channels active together.
  • VOLi is the OUTi pin voltage for the load current ILi.

10.4 Thermal Considerations

TI recommends to limit ULN2003LV IC’s die junction temperature to less than 125°C. The IC junction temperature is directly proportional to the on-chip power dissipation. Use the following equation to calculate the maximum allowable on-chip power dissipation for a target IC junction temperature:

Equation 4. ULN2003LV eq2_lrs059.gif


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

10.4.1 Improving Package Thermal Performance

The package RθJA value under standard conditions on a High-K board is listed in the Dissipation Ratings. RθJA value depends on the PCB layout. An external heat sink and/or a cooling mechanism, like a cold air fan, can help reduce RθJA and thus improve device thermal capabilities. Refer to TI’s design support web page at for a general guidance on improving device thermal performance.