The ULN2003B device is a high-voltage, high-current Darlington transistor array. This device consists of seven NPN Darlington pairs that feature high-voltage outputs with common-cathode clamp diodes for switching inductive loads. The collector-current rating of a single Darlington pair is 500 mA. The Darlington pairs can be paralleled for higher current capability. The ULN2003B has a 2.7-kΩ series base resistor for each Darlington pair for operation directly with TTL or CMOS devices.