ULN2003A IC

The ULN2003A 7-Channel Darlington Driver is a logic compatible NPN Darlington transistor array for driving high-current/high-voltage loads.

PACKAGE INCLUDES:

• ULN2003A 7-Channel Darlington Driver

KEY FEATURES OF ULN2003A 7-CHANNEL DARLINGTON DRIVER:

• 7 Darlington transistor pair channels

  

  ULN2003-Schematic Diagram

• 50V @ 500mA sink current capability

•  Built-in kick-back diodes for driving inductive loads

• Suitable for driving high voltage LEDs, small motors, fans, relays

• 3.3 and 5V compatible inputs

The ULN2003 has 7 separate drive channels each comprised of  high current NPN Darlington transistor pairs with built-in kick-back diodes for switching inductive loads like motors.

Due to the number of outputs, it is particularly well suited for driving higher powered 7-Segment displays but it can be used to drive solenoids, relays, fans, small motors and many other moderate power devices.

The driver is used on the low side of the load which means it is connected between the load and

 ground and are used to sink current to ground.

A single channel can handle up to 50V@ 500mA.  The maximum per channel overall will depend on how many channels are being used and the duty that the channel is switching at.  Refer to Fig 5 in the datasheet for the breakdown.  The channels can be connected in parallel for higher current capability.

Inputs are 3.3 and 5V logic compatible.

These chips have been around for a long time and are popular for driving moderate power devices where you need to control more voltage or current then a uC can handle directly.  They are also very inexpensive.

The parts are in a DIP-16 package so they are breadboard friendly.