The ULN2803A device is a 50 V, 500 mA Darlington transistor array. The device consists of eight NPN Darlington pairs that feature high-voltage outputs with common-cathode clamp diodes for switching inductive loads. The collector-current rating of each Darlington pair is 500 mA.
What is a Darlington array?
Darlington devices are high-voltage, high-current switch arrays containing multiple open-collector Darlington pairs or multiple Darlington transistors with common emitters, and integral suppression diodes for inductive loads.
Which of the following is a Darlington pair?
A Darlington pair is a two-transistor circuit with the emitter of one transistor is connected to the base of other transistors, while both collector terminals are connected to the common terminal. It has high current gain β; (equal to the product of current gain of individual transistors)
What are Darlington transistor used for?
The Darlington transistor circuit lends itself to use in small driver chips for LEDs and other small devices. The high current gain of the Darlington circuit means that these small driver chips can be used to interface LEDs and other devices to logic chips.
How do you make a Darlington pair transistor?
A 60W load with 15V input voltage needs to be switched using two NPN transistors, creating a Darlington pair. The first Transistor gain will be 30 and the second transistor gain will be 95.