ULN2003AIDR

Overview

The ULN2003AIDR 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 with a maximum collector-emitter voltage of 50 V and supports a continuous collector current of 500 mA per channel. It features series input resistors optimized for direct interfacing with 5 V TTL or CMOS logic. Packaged in a 16-pin SOIC (DR) surface-mount format, it functions as a low-side driver suitable for applications requiring robust current sinking capabilities.

Feature Summary

• Integrates seven independent Darlington transistor channels with common emitter configuration
• Includes built-in clamp diodes across each output to suppress inductive voltage spikes
• Features internal base resistors allowing direct connection to standard logic families
• Provides open-collector outputs capable of handling high voltage and current loads

Applications

• Relay drivers for industrial control systems
• Stepping motor and DC brush motor drivers
• High-current light and display drivers
• Line drivers and logic buffer interfaces

Procurement Notes

Verify the specific suffix DR indicates the tape-and-reel surface-mount packaging variant distinct from through-hole DIP versions. Confirm the manufacturer designation remains Texas Instruments and check for RoHS compliance status on the latest datasheet revision. Ensure the ordering part number matches the required package style and temperature rating for the target application environment.

Selection Notes

Select this component when driving multiple inductive loads such as relays or solenoids directly from microcontrollers or logic gates. The integrated input resistors simplify circuit design by eliminating external components. Choose this over ULN2004 variants if the control logic operates at 5 V TTL levels rather than higher voltage CMOS ranges. Consider thermal dissipation requirements when paralleling outputs for currents exceeding single-channel ratings.

Part Context

This part belongs to the ULN200xA family of high-voltage Darlington arrays developed by Texas Instruments. It shares electrical characteristics with the ULN2003AN through-hole version but utilizes an SOIC-16 surface-mount package. The series is designed to replace discrete transistor networks, offering a compact solution for driving heavy loads while maintaining compatibility with standard digital logic inputs.

Replacement Considerations

• ULN2003AN (Through-hole equivalent)
• ULN2003APWR (TSSOP alternative)

FAQ

What is the function of the integrated diodes in the ULN2003AIDR?

The integrated diodes are connected between each output and the common collector supply pin. They act as clamp diodes to protect the transistors from voltage spikes generated by inductive loads like relays or motors when switched off.

Can the outputs of the ULN2003AIDR be paralleled?

Yes, outputs can be paralleled to increase the total load current capability beyond the single-channel 500 mA limit, provided thermal constraints are managed appropriately.

Is the ULN2003AIDR compatible with 5V CMOS logic?

Yes, the internal series input resistors are sized to allow direct interfacing with both 5V TTL and 5V CMOS logic families without additional level-shifting components.