1The ULN2803A device is a 50 V, 500 mA Darlington transistor array. 2The device consists of eight NPN Darlington pairs, which have a high voltage output and a common cathode clamp diode for switching inductive loads. 3The collector current rating of each Darlington pair is 500 mA. Darlington pairs can be connected in parallel to increase current capacity. 4Applications include relay drivers, hammer drivers, lamps drivers, display drivers (LED and gas discharge), line drivers and logic buffers. 5Each Darlington pair of ULN2803A devices has a 7k series base resistance and can work directly with TTL or 5V CMOS devices