ULN2003AIN

Overview

The ULN2003AIN is a high-voltage, high-current Darlington transistor array manufactured by Texas Instruments. It integrates seven NPN Darlington pairs with common emitters and integrated clamp diodes for inductive load switching. The device operates within a temperature range of -40°C to 85°C and features a maximum continuous collector current of 500 mA per channel. Key electrical parameters include a maximum collector-emitter voltage (Vceo) of 50 V, a maximum collector-emitter saturation voltage (VceSAT) of 1.1 V, and a minimum DC current gain (hFE) of 1000. It utilizes a 16-pin PDIP package.

Feature Summary

• Integrates seven independent NPN Darlington pairs with common emitter configuration
• Includes built-in clamp diodes across each output and input for inductive load protection
• Features internal base resistors compatible with TTL, CMOS, PMOS, and DTL logic families
• Designed for driving high-power loads such as relays, solenoids, and stepper motors

Applications

• Relay drivers
• Stepper motor controllers
• Solenoid and valve actuators
• High-current logic buffers

Procurement Notes

Verify the specific suffix 'IN' against official Texas Instruments documentation to confirm it denotes the industrial temperature grade variant (-40°C to 85°C). Ensure the ordering part number matches the exact package style required for your PCB layout. Cross-reference the manufacturer's latest datasheet revision to validate pinout compatibility and absolute maximum ratings before finalizing procurement.

Selection Notes

Select this component when driving multiple inductive loads requiring up to 500 mA per channel from a low-current logic source. The integrated 2.7 kΩ base resistors simplify interface design by eliminating external components. Verify that the system's thermal environment remains within the specified -40°C to 85°C operating range to ensure reliable performance and longevity of the semiconductor junctions.

Part Context

The ULN2003A series is a legacy high-voltage Darlington array widely used in industrial control systems. The ULN2003AIN specifically represents the industrial-grade version of this family, offering extended temperature capabilities compared to commercial variants. It serves as a direct replacement for older Sprague Electric designs and remains a standard solution for multi-channel power switching applications.

Replacement Considerations

Compatible substitutes include the ULN2003AN (commercial grade) and ULN2003A from other manufacturers like STMicroelectronics. Verify that alternative sources maintain identical pinouts, current ratings, and voltage specifications to ensure drop-in compatibility without circuit redesign.