Texas Instruments

ULN2004AN

ULN2004AN Description

The ULN2004AN from Texas Instruments is a high-voltage, high-current NPN Darlington transistor array designed for low-side switching applications. Housed in a 16-pin DIP package, it integrates seven Darlington pairs with common emitters, capable of driving loads up to 50V and 500mA per channel. This device operates without an external supply voltage (Vcc/Vdd), simplifying circuit design. Its inverting input logic ensures compatibility with TTL, CMOS, and PMOS outputs, making it versatile for interfacing with microcontrollers or logic circuits. The ULN2004AN is part of the ULx200xA series, offering robust performance in relay, solenoid, and lamp driving applications.

ULN2004AN Features

• Output Configuration: Low-side NPN Darlington array with 7 independent channels (1:1 input-to-output ratio).
• High Voltage/Current Handling: Supports 50V load voltage and 500mA continuous current per channel.
• Input Compatibility: Inverting logic inputs (TTL/CMOS/PMOS compatible).
• Simplified Design: No external Vcc/Vdd required, reducing component count.
• Reliability: ROHS3 compliant and REACH unaffected, ensuring environmental compliance.
• Robust Packaging: Through-hole 16-DIP for easy prototyping and industrial use.
• Wide Operating Range: Suitable for harsh environments with Not Applicable MSL (Moisture Sensitivity Level).

ULN2004AN Applications

The ULN2004AN excels in industrial, automotive, and consumer electronics where high-current switching is critical:

• Relay/Solenoid Drivers: Ideal for controlling electromechanical relays or solenoids in automation systems.
• Stepper Motor Control: Used as a driver for unipolar stepper motors in CNC machines or 3D printers.
• LED/Lamp Drivers: Efficiently manages high-power LEDs or incandescent lamps in display panels.
• Logic Interface: Bridges low-power logic circuits (e.g., microcontrollers) to high-current peripherals.
• Automotive Systems: Suitable for driving inductive loads in automotive control modules.

Conclusion of ULN2004AN

The ULN2004AN stands out for its high-voltage tolerance, compact integration, and ease of use, making it a preferred choice for low-side switching tasks. Its Darlington pair design ensures high current gain, while the inverting input logic simplifies interfacing with digital systems. Although marked as Last Time Buy, its legacy in relay driving, motor control, and industrial automation remains unmatched. Engineers seeking a reliable, no-frills driver IC for medium-power applications will find the ULN2004AN a cost-effective solution.