STMicroelectronics

ULN2074B

ULN2074B Description

The ULN2074B from STMicroelectronics is a high-voltage, high-current NPN Darlington transistor array designed for demanding switching applications. This quad Darlington configuration integrates four independent NPN Darlington pairs in a single 16-pin DIP package, offering robust performance with a collector-emitter breakdown voltage (V_CE) of 50V and a maximum collector current (I_C) of 1.75A. The device is optimized for low saturation voltage (1.4V @ 2mA, 1.25A), ensuring efficient power handling with minimal losses.

ULN2074B Features

• High Current Handling: Supports up to 1.75A per channel, making it suitable for driving relays, solenoids, and motors.
• Low Saturation Voltage: 1.4V max at 1.25A reduces power dissipation, improving thermal performance.
• Quad Darlington Configuration: Four independent Darlington pairs in one package, saving board space and simplifying design.
• High Voltage Tolerance: 50V collector-emitter breakdown ensures reliability in industrial and automotive environments.
• Robust Packaging: Through-hole 16DIP for easy prototyping and assembly.
• Compliance: ROHS3 compliant and REACH unaffected, meeting environmental standards.

ULN2074B Applications

• Industrial Control Systems: Ideal for driving relays, stepper motors, and inductive loads in automation equipment.
• Automotive Electronics: Used in power window controllers, fuel injectors, and lighting systems due to its high-voltage tolerance.
• Consumer Electronics: Suitable for printer head drivers, display backlighting, and appliance control circuits.
• Test & Measurement Equipment: Provides reliable switching for load simulation and signal conditioning.

Conclusion of ULN2074B

The ULN2074B stands out as a versatile, high-performance Darlington array for medium-power switching applications. Its low saturation voltage, high current capability, and compact quad configuration make it a preferred choice over discrete transistors in space-constrained designs. While marked as obsolete, it remains a reliable solution for legacy systems and replacements. Engineers value its durability, ease of integration, and compliance with environmental standards, ensuring long-term reliability in harsh operating conditions.