ULN2003BN

Overview

The ULN2003BN is a high-voltage, high-current Darlington transistor array manufactured by Texas Instruments. It integrates seven NPN Darlington pairs within a single package, each featuring common emitters and open-collector outputs. The component supports a maximum continuous collector current of 500 mA per channel with a peak capability of 600 mA. It operates with a maximum collector-emitter voltage (Vceo) of 50 V and includes integrated suppression diodes for inductive load protection. Designed for through-hole mounting, it utilizes a 16-pin PDIP package with dimensions of 19.3 mm length and 4.57 mm height. The device functions within an operating temperature range of -20°C to +70°C.

Feature Summary

• Integrates seven independent NPN Darlington pairs with common emitters for multi-channel switching
• Includes built-in suppression diodes across inputs and outputs to protect against inductive load back-EMF
• Features input pins positioned opposite output pins on the package to facilitate simplified printed circuit board layout

Applications

• Driving stepper motor coils in motion control systems
• Actuating electromagnetic relays and solenoids
• Powering LED displays and filament lamps
• Serving as high-power buffers for logic signal translation

Procurement Notes

Verify the specific manufacturer origin when sourcing the ULN2003BN, as multiple vendors produce this part number. Confirm that the package matches the standard 16-pin DIP form factor required for your application. Ensure the thermal characteristics align with your system's heat dissipation requirements, as power dissipation depends on ambient conditions and load currents.

Selection Notes

Select the ULN2003BN when driving inductive loads such as relays or motors that require internal flyback protection. Choose this component over discrete transistors to reduce board space and simplify wiring due to the shared emitter configuration. Verify that the input logic levels are compatible with TTL or CMOS standards, as the ULN2003A variant is specifically optimized for these families.

Part Context

The ULN2003BN belongs to the ULN2000 series of high-voltage Darlington arrays produced by Texas Instruments. This series also includes variants like the ULN2003AN and ULN2003D1, which differ primarily in packaging styles such as plastic DIP or small outline packages. The 'B' suffix typically denotes a specific manufacturing lot or regional distribution code rather than a functional change from the standard ULN2003A specification.

Replacement Considerations

Direct replacements include the ULN2003AN for identical performance in a standard DIP package. For surface-mount applications, the ULN2003D1 serves as a pin-compatible alternative in an SOIC-16 package. Other manufacturers offer equivalent parts such as the STMicroelectronics ULN2003D1013TR.