ULN2003A IC (original)

The ULN2003A is a <mark>high-voltage, high-current Darlington transistor array IC</mark>. It contains seven NPN Darlington pairs that allow microcontrollers (like Arduino or Raspberry Pi) to drive high-power loads like relays, solenoids, and stepper motors that require more current than the logic pins can safely provide.

Key Features & Specifications

• Channels: 7 independent Darlington pairs.
• Current Rating: Up to 500 mA per channel (can be paralleled for higher loads).
• Voltage Rating: Up to 50V output.
• Logic Compatibility: Inputs have built-in 2.7 kΩ base resistors, allowing direct connection to 5V TTL or CMOS logic without external resistors.
• Inductive Protection: Features internal flyback/suppression diodes to safely absorb voltage spikes when switching inductive loads.