SLRS064B June   2014  – August 2016 ULN2003B

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 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, TA = 25°C
    6. 6.6 Electrical Characteristics, TA = -40°C to +105°C
    7. 6.7 Switching Characteristics, TA = 25°C
    8. 6.8 Switching Characteristics, TA = -40°C to +105°C
    9. 6.9 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
    4. 8.4 Device Functional Modes
      1. 8.4.1 Inductive Load Drive
      2. 8.4.2 Resistive Load Drive
  9. 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 Drive Current
        2. 9.2.2.2 Output Low Voltage
        3. 9.2.2.3 Power Dissipation and Temperature
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Receiving Notification of Documentation Updates
    2. 12.2 Community Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8 Detailed Description

8.1 Overview

This standard device has proven ubiquity and versatility across a wide range of applications. This is due to it's integration of 7 Darlington transistors that are capable of sinking up to 500 mA and wide GPIO range capability.

The ULN2003B comprises seven high voltage, high current NPN Darlington transistor pairs. All units feature a common emitter and open collector outputs. To maximize their effectiveness, these units contain suppression diodes for inductive loads. The ULN2003B has a series base resistor to each Darlington pair, thus allowing operation directly with TTL or CMOS operating at supply voltages of 5 V or 3.3 V. The ULN2003B offers solutions to a great many interface needs, including solenoids, relays, lamps, small motors, and LEDs. Applications requiring sink currents beyond the capability of a single output may be accommodated by paralleling the outputs.

This device can operate over a wide temperature range (–40°C to +105°C).

8.2 Functional Block Diagram

ULN2003B sch_lrs064.gif
All resistor values shown are nominal.
Figure 22. Schematic (Each Driver)

8.3 Feature Description

Each channel of ULN2003B consists of Darlington connected NPN transistors. This connection creates the effect of a single transistor with a very high current gain. This beta can be high at certain currents see Figure 5.

The GPIO voltage is converted to base current through the 2.7-kΩ resistor connected between the input and base of the pre-driver Darlington NPN. The 7.2-kΩ and 3-kΩ resistors connected between the base and emitter of each respective NPN act as pull-downs and suppress the amount of leakage that may occur from the input.

The diodes connected between the output and COM pin is used to suppress the kick-back voltage from an inductive load that is excited when the NPN drivers are turned off (stop sinking) and the stored energy in the coils causes a reverse current to flow into the coil supply through the kick-back diode.

In normal operation the diodes on base and collector pins to emitter will be reversed biased. If these diode are forward biased, internal parasitic NPN transistors will draw (a nearly equal) current from other (nearby) device pins.

8.4 Device Functional Modes

8.4.1 Inductive Load Drive

When the COM pin is tied to the coil supply voltage, ULN2003B is able to drive inductive loads and suppress the kick-back voltage through the internal free wheeling diodes.

8.4.2 Resistive Load Drive

When driving a resistive load, a pull-up resistor is needed in order for ULN2003B to sink current and for there to be a logic high level. The COM pin can be left floating for these applications.