ULN 2004

The ULN 2004 is a high-voltage, high-current Darlington transistor array engineered to drive relays, stepper motors, lamps and other heavy loads from logic-level inputs. Its integrated design combines reliable switching capability with protective features to simplify circuit design in both industrial and hobbyist applications. 7 high-voltage Darlington pairs capable of handling up to 50V. Maximum collector current of 500mA per channel to support a wide range of loads. Built-in clamping (flyback) diodes to protect against voltage spikes from inductive loads. Standard 16-pin DIP package for straightforward PCB and breadboard use. Compatible with TTL and CMOS logic levels for direct interfacing with microcontrollers and digital logic. Compared with earlier driver arrays, the ULN 2004 provides improved current capacity and integrated diode protection, which reduces external component count and enhances overall circuit reliability. Its compact footprint and standardized package make it suitable for retrofit and new designs where board space and component minimization are priorities. Engineering strengths include dependable transistor pairs that switch heavy loads without excessive heating and internal clamping diodes that safeguard sensitive control electronics from back-EMF produced by inductive components. Logic-level compatibility simplifies wiring and reduces the need for level-shifting circuitry, enabling faster development and more robust control systems. The ULN 2004 represents a practical balance of power handling, protection, and ease of integration for a broad range of electronic control applications.