The ULN2803A 8-Channel Darlington Driver is a logic compatible NPN Darlington transistor array for driving high current / high voltage loads.
- ULN2803A 8-Channel Darlington Driver
KEY FEATURES OF ULN2803A 8-CHANNEL DARLINGTON DRIVER:
- 8 Darlington transistor pair channels
- 50V @ 500mA current sink 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 ULN2803A has 8 separate drive channels each comprised of high current NPN Darlington transistor pairs with built-in kick-back diodes for switching inductive loads like motors.
It is well suited for driving higher powered 7-Segment displays, 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 cycle that the channel is switching at. 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-18 package so they are breadboard friendly.
- For a 7-channel device which can be handy for 7-Seg displays, check out the ULN2003.
|Maximum Ratings||Output Voltage||50V|
|Collector Current (continuous)||500mA|
|Base Current (continuous)||25mA|
|Turn on/off Delay||0.25uS (typ.)|
|Package Type||Plastic, thru-hole|
|Mfr||Various: Toshiba/ON Semi|