ULN2003APWR

Overview

The ULN2003APWR 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 an integrated flyback diode for inductive load protection. The device operates with a maximum collector-emitter voltage of 50 V and supports a continuous collector current of 500 mA per channel. Designed for through-hole or surface-mount compatibility depending on the specific variant, it utilizes a 16-pin TSSOP package. The internal 2.7 kΩ base resistors enable direct interfacing with TTL, CMOS, PMOS, and DTL logic families without additional buffering components.

Feature Summary

• Integrates seven independent NPN Darlington pairs with common emitters for simplified circuit design
• Includes built-in clamping diodes across each output to suppress back-EMF from inductive loads
• Features internal base resistors allowing direct connection to standard logic outputs

Applications

• Relay driver circuits for industrial control systems
• Stepper motor and DC brushed motor drivers
• LED and gas discharge lamp drivers
• Line drivers and logic buffer interfaces

Procurement Notes

Verify the exact suffix against the manufacturer's official datasheet to confirm pinout and electrical specifications. Ensure the ordering part number matches the required package type and temperature range. Cross-reference the component marking with the official documentation to prevent counterfeit substitution. Confirm RoHS compliance status if required for your manufacturing process.

Selection Notes

Select this component when driving inductive loads such as relays or solenoids that require integrated freewheeling diodes. Choose this part over discrete transistors to reduce board space and assembly time. Verify that the input logic levels match the internal resistor configuration for proper saturation. Consider thermal dissipation requirements if operating near the maximum current limits.

Part Context

This component belongs to the ULN2003A family of high-voltage Darlington arrays. It serves as a bridge between low-power digital logic and high-power analog loads. The 'PWR' suffix typically denotes a plastic small-outline package variant. It is widely used in embedded systems where multiple high-current switches are needed from a single microcontroller port.

Replacement Considerations

ULN2003AN: PDIP package equivalent. ULN2003D: SOIC package equivalent. ULN2803A: Eight-channel variant with similar characteristics.