ULN2003AIN Equivalent & Substitute Parts

Part Overview

The ULN2003AIN is a power management integrated circuit manufactured by Texas Instruments, classified as a Power Switch/Driver with 1:1 Darlington configuration. This 7-output relay and solenoid driver operates at 50V maximum load voltage with 500mA output current per channel in a 16-PDIP through-hole package. The part is currently in Last Time Buy status, making identification of active equivalent and substitute parts essential for ongoing design support and procurement planning.

Substiute Parts

ULN2003AIN

Texas InstrumentsIn Stock: 46712ULN2003AIN Datasheet

Current PartRFQ

ULQ2001A

STMicroelectronicsIn Stock: 2131ULQ2001A Datasheet

DirectRFQ

ULQ2003A

STMicroelectronicsIn Stock: 18539ULQ2003A Datasheet

DirectRFQ

ULQ2004A

STMicroelectronicsIn Stock: 2370ULQ2004A Datasheet

DirectRFQ

ULN2003AN

Texas InstrumentsIn Stock: 55198ULN2003AN Datasheet

MFR RecommendedRFQ

TBD62003APG

Toshiba Semiconductor and StorageIn Stock: 63468TBD62003APG Datasheet

MFR RecommendedRFQ

ULN2001A

STMicroelectronicsIn Stock: 22800ULN2001A Datasheet

MFR RecommendedRFQ

ULN2002A

STMicroelectronicsIn Stock: 2363ULN2002A Datasheet

MFR RecommendedRFQ

ULN2003A

UMWIn Stock: 39129ULN2003A Datasheet

MFR RecommendedRFQ

ULN2004A

STMicroelectronicsIn Stock: 35497ULN2004A Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the ULN2003AIN is determined by the following critical parameters:

• Output Configuration & Type: Low-side output with Darlington or equivalent switching topology
• Electrical Ratings: 50V maximum load voltage and 500mA maximum output current per channel
• Channel Count: 7 independent output channels
• Input/Output Ratio: 1:1 configuration
• Package Compatibility: 16-DIP through-hole form factor (0.300", 7.62mm pitch)
• Functional Classification: Relay and solenoid driver application

Substitute parts are grouped into three categories based on manufacturer status and output type:

Category 1 - Direct Darlington Equivalents (Active Status): ULN2003AN, ULQ2003A, ULQ2001A, ULQ2004A. These parts maintain identical electrical specifications and Darlington output topology with active product status.

Category 2 - Alternative Output Type (Active Status): TBD62003APG (N-Channel output). Functionally compatible for relay and solenoid driving applications with equivalent electrical ratings but different output transistor topology.

Category 3 - NPN Output Variants (Active Status): ULN2001A, ULN2002A, ULN2004A. These parts provide NPN output configuration instead of Darlington, suitable for applications where output type flexibility is acceptable.

Category 4 - Surface Mount Alternative: ULN2003A (UMW). Maintains Darlington output type and electrical specifications in 16-SOIC surface-mount package for PCB integration alternatives.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation - ULN2003AN (Texas Instruments): This part maintains manufacturer continuity with Texas Instruments and preserves the Darlington output topology of the original ULN2003AIN. Active product status ensures long-term availability and supply chain stability. Operating temperature range of -40°C to 70°C covers standard industrial applications. Inventory of 55,100 units supports immediate procurement.

Secondary Recommendation - ULQ2003A (STMicroelectronics): Direct Darlington equivalent with identical electrical specifications and 16-DIP through-hole package. Extended operating temperature range to 150°C (TJ) provides thermal margin for demanding environments. Active product status with 18,474 units in stock.

Alternative for Extended Temperature Range - ULQ2001A or ULQ2004A (STMicroelectronics): Both parts offer Darlington output configuration with 150°C maximum junction temperature, suitable for high-temperature applications. Vce saturation specifications differ slightly (ULQ2001A: 1.6V vs. ULQ2004A: 1.7V @ 500µA, 350mA), with negligible impact on relay and solenoid driver applications.

Alternative Output Type - TBD62003APG (Toshiba): N-Channel output topology provides functional equivalence for relay and solenoid driving with identical electrical ratings. Highest inventory availability (63,444 units) and active product status. Operating temperature range -40°C to 85°C. Select only if circuit design accommodates N-Channel output characteristics.

Surface Mount Alternative - ULN2003A (UMW): Maintains Darlington output and electrical specifications in 16-SOIC surface-mount package. Suitable for new PCB designs or rework requiring surface-mount components. Active status with 39,100 units available.

NPN Output Variants - ULN2001A, ULN2002A, ULN2004A (STMicroelectronics): These parts provide NPN output configuration instead of Darlington. Select only if circuit topology explicitly requires NPN output characteristics. All three maintain 50V/500mA electrical ratings and 16-DIP through-hole package.

All recommended substitutes carry ROHS3 compliance and REACH Unaffected status, matching the original part's regulatory classification.

Frequently Asked Questions (FAQ)

Q: Can ULN2003AN directly replace ULN2003AIN in existing designs?

A: Yes. ULN2003AN maintains identical electrical specifications (50V load voltage, 500mA output current, 7 Darlington outputs, 1:1 ratio, low-side configuration) and 16-DIP through-hole package. The primary difference is operating temperature range: ULN2003AN operates -40°C to 70°C versus ULN2003AIN at -40°C to 105°C. For applications within the -40°C to 70°C range, ULN2003AN is a direct substitute.

Q: What is the difference between Darlington and NPN output types in these parts?

A: Darlington output (ULN2003AIN, ULN2003AN, ULQ2003A, ULQ2001A, ULQ2004A) uses a Darlington pair configuration providing higher current gain and lower saturation voltage. NPN output (ULN2001A, ULN2002A, ULN2004A) uses single NPN transistors. For relay and solenoid driving, both are functionally equivalent at the specified 500mA output current. Darlington configuration offers better performance at lower input currents.

Q: Is TBD62003APG compatible with ULN2003AIN?

A: TBD62003APG is functionally compatible for relay and solenoid driver applications with identical electrical ratings (50V, 500mA, 7 outputs, 1:1 ratio, low-side configuration) and 16-DIP package. The key difference is output type: TBD62003APG uses N-Channel MOSFET output instead of Darlington. Circuit designs must accommodate N-Channel output characteristics. Operating temperature range is -40°C to 85°C.

Q: Why does ULQ2003A have a higher maximum junction temperature (150°C) than ULN2003AIN (105°C)?

A: Maximum junction temperature (TJ) reflects the semiconductor die's thermal rating, while ambient operating temperature (TA) reflects the package's rated environment. ULQ2003A's 150°C TJ provides greater thermal margin in high-temperature applications but does not extend the ambient operating range beyond -40°C to 150°C (TJ). For ambient temperature specifications, refer to the TA rating: ULQ2003A operates -40°C to 150°C (TJ), which is higher than ULN2003AIN's -40°C to 105°C (TA).

Q: Can I use the surface-mount ULN2003A (UMW) instead of the through-hole ULN2003AIN?

A: ULN2003A (UMW) maintains identical electrical specifications and Darlington output configuration but uses 16-SOIC surface-mount package instead of 16-DIP through-hole. Physical package incompatibility prevents direct board-level substitution. Use only for new PCB designs or rework projects where surface-mount components are specified.

Q: What inventory considerations should guide part selection?

A: TBD62003APG offers the highest inventory (63,444 units), followed by ULN2003AN (55,100 units) and ULN2004A (35,400 units). ULQ2001A and ULQ2004A have lower inventory (2,100 and 2,293 units respectively). For long-term supply chain stability, prioritize parts with higher inventory levels and active product status.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All listed substitute parts carry ROHS3 compliance and REACH Unaffected status, matching the original ULN2003AIN's regulatory classification.