ULN2803: NPN Darlington array, 8 channel - ULN2803A

8 Darlington into a single chip to drive motors, relays and solenoids

Give muscle to your output pins with this 8 amazing Darlington! This integrated circuit in DIP format contains 8 driver circuit capable of drive 500mA up to 50V power supply and incorporates anti fly-back diodes (also called "freewheeling diode"), which makes it possible to control windings.  

This allows the small microcontroller (or microcomputer) to easily control de solenoids, relays, continuous motors (in one direction) and unipolar step-by-step motors. 

Note that it is an 'open collector' circuit - It can only be used to connect a load to ground and there will be a voltage drop of 1 Volt (or more)... voltage loss caused by the internal transistors.

The inputs can be controlled in logic 3.3V or 5V.

2.54mm pin spacing make it easy to place these components on the breadboard, prototyping board and perfboard.

Technical details

• Type of Transistor: Power Darlington
• Polarity of transistors: NPN
• Emitter collector voltage V(br)ceo: 50V
• Max output voltage: 50V
• Dissipation power Pd: 2.25W
• Collector current (continuous): 500mA
• Current gain hFE: 1000
• Operating temperature: -20°C à 85°C
• Type of case: DIP (through Hole, 2.54mm spacing)
• Numbers of pins: 18
• Collector current Ic Max: 500mA in continuous.
• Indication: ULN2803A
• Input type: CMOS, TTL
• Max input voltage: 5V
• Numbers of channels: 8

See the technical data sheet of ULN2803A