It consists of an array of seven NPN Darlington transistors capable of 500 mA, 50 V output.
It features common-cathode flyback diodes for switching inductive loads (such as servomotors).
[1][2] In the same family are ULN2002A, ULN2004A, as well as ULQ2003A and ULQ2004A, designed for different logic input levels.
The seven Darlington pairs in ULN2003 can operate independently except the common cathode diodes that connect to their respective collectors.
Main specifications: Typical usage of the ULN2003A is in driver circuits for relays, solenoids, lamp and LED displays, stepper motors, logic buffers and line drivers.