LM2940CSX-5.0 Equivalent & Substitute Parts

Part Overview

The LM2940CSX-5.0 is a linear voltage regulator IC from Texas Instruments, delivering a fixed 5V output at 1A in a TO-263 (DDPAK-3) surface mount package. This device is classified as not for new designs, making equivalent and substitute parts essential for ongoing production support and design updates. The part provides positive fixed output regulation with integrated protection features including over-current, over-temperature, reverse polarity, and short-circuit protection. Finding suitable alternatives ensures design continuity and access to actively supported components.

Key Parameters

Parameter	Value
Output Voltage (Fixed)	5V
Output Current	1A
Input Voltage (Max)	26V
Dropout Voltage (Max)	0.8V @ 1A
Quiescent Current	10 mA
Package Type	TO-263 (DDPAK-3)
Operating Temperature Range	0°C ~ 125°C
Protection Features	Over Current, Over Temperature, Reverse Polarity, Short Circuit

Substitute Part Grouping Explanation

Substitution eligibility is determined by the following critical parameters:

Output voltage fixed at 5V
Output current capability of 1A or greater
Input voltage maximum of 26V or greater
TO-263 (DDPAK-3) package compatibility
Surface mount mounting type
Protection features including over-current and over-temperature

Substitute parts are grouped into three categories based on output current capacity: direct equivalents (1A), enhanced capacity (1.25A to 1.5A), and high-capacity alternatives (3A). All listed substitutes maintain the same output voltage, package footprint, and core protection architecture.

Parameter Comparison

Part Number	Manufacturer	Output Current	Dropout Voltage	Input Voltage (Max)	Quiescent Current	Operating Temperature	Product Status	RoHS Status
LM2940CSX-5.0	Texas Instruments	1A	0.8V @ 1A	26V	10 mA	0°C ~ 125°C	Not For New Designs	RoHS non-compliant
LM2940CSX-5.0/NOPB	Texas Instruments	1A	0.8V @ 1A	26V	10 mA	0°C ~ 125°C	Active	ROHS3 Compliant
BD50C0AFP2-CE2	Rohm Semiconductor	1A	0.5V @ 500mA	26.5V	2.5 mA	-40°C ~ 125°C	Active	ROHS3 Compliant
MIC2937A-5.0WU	Microchip Technology	750mA	Not specified	26V	300 µA	-40°C ~ 125°C	Active	ROHS3 Compliant
MIC2937A-5.0WU-TR	Microchip Technology	750mA	0.75V @ 750mA	26V	300 µA	-40°C ~ 125°C	Active	ROHS3 Compliant
MIC2940A-5.0WU	Microchip Technology	1.25A	0.6V @ 1.25A	26V	500 µA	-40°C ~ 125°C	Active	ROHS3 Compliant
MIC2940A-5.0WU-TR	Microchip Technology	1.25A	0.6V @ 1.25A	26V	500 µA	-40°C ~ 125°C	Active	ROHS3 Compliant
MIC29150-5.0WU	Microchip Technology	1.5A	0.6V @ 1.5A	26V	Not specified	-40°C ~ 125°C	Active	ROHS3 Compliant
MIC29150-5.0WU-TR	Microchip Technology	1.5A	0.6V @ 1.5A	26V	Not specified	-40°C ~ 125°C	Active	ROHS3 Compliant
MIC29300-5.0WU	Microchip Technology	3A	0.6V @ 3A	26V	Not specified	-40°C ~ 125°C	Active	ROHS3 Compliant
MIC29300-5.0WU-TR	Microchip Technology	3A	0.6V @ 3A	26V	Not specified	-40°C ~ 125°C	Active	ROHS3 Compliant

Engineering Selection Recommendations

For direct replacement with identical electrical performance and compliance status, LM2940CSX-5.0/NOPB from Texas Instruments is the primary choice. This part maintains 1A output current and 0.8V dropout voltage specifications while offering active product status and ROHS3 compliance, addressing the obsolescence concern of the original LM2940CSX-5.0.

For applications requiring enhanced current capacity or improved thermal performance, Microchip Technology MIC2940A-5.0WU and MIC2940A-5.0WU-TR deliver 1.25A output with lower dropout voltage (0.6V @ 1.25A) and extended operating temperature range (-40°C ~ 125°C). Both variants are ROHS3 compliant and actively supported.

For high-current applications, MIC29150-5.0WU and MIC29150-5.0WU-TR provide 1.5A output, while MIC29300-5.0WU and MIC29300-5.0WU-TR deliver 3A output. All Microchip alternatives maintain TO-263 package compatibility and active product status.

The Rohm Semiconductor BD50C0AFP2-CE2 offers automotive-grade qualification (AEC-Q100) with superior quiescent current (2.5 mA) and lower dropout voltage (0.5V @ 500mA), suitable for automotive and industrial applications requiring extended temperature range (-40°C ~ 125°C).

MIC2937A-5.0WU and MIC2937A-5.0WU-TR are suitable only for applications where 750mA output current is sufficient, offering the lowest quiescent current (300 µA) among all alternatives.

Frequently Asked Questions (FAQ)

Q: Can LM2940CSX-5.0/NOPB directly replace LM2940CSX-5.0?

A: Yes. Both parts deliver identical electrical specifications: 5V fixed output, 1A current, 0.8V dropout voltage, and TO-263 package. The primary difference is product status and compliance: LM2940CSX-5.0/NOPB is active and ROHS3 compliant, while the original is not for new designs and RoHS non-compliant.

Q: What is the difference between Tube and Tape & Reel packaging for Microchip parts?

A: Tube and Tape & Reel (TR) packaging variants contain identical die and electrical specifications. The difference is packaging format for automated assembly: Tube packaging is used for manual or lower-volume assembly, while Tape & Reel is optimized for high-speed pick-and-place equipment. Electrical performance is identical.

Q: Can I use MIC29300-5.0WU-TR (3A) as a drop-in replacement for LM2940CSX-5.0 (1A)?

A: Yes, from an electrical compatibility standpoint. The MIC29300-5.0WU-TR maintains 5V output, TO-263 package, and all required protection features. Higher current capacity does not affect operation in 1A applications. However, verify PCB thermal design, as higher current capability may result in different thermal characteristics.

Q: Why does BD50C0AFP2-CE2 have lower quiescent current than other options?

A: The BD50C0AFP2-CE2 from Rohm Semiconductor incorporates different internal circuit design optimized for low standby power consumption. This is a design characteristic of the Rohm architecture and does not affect functional compatibility with the LM2940CSX-5.0 in applications requiring 5V, 1A regulation.

Q: Are all substitute parts RoHS compliant?

A: All listed substitute parts are ROHS3 compliant. The original LM2940CSX-5.0 is RoHS non-compliant. If RoHS compliance is a design requirement, use LM2940CSX-5.0/NOPB or any Microchip or Rohm alternative listed.

Q: What is the operating temperature difference between LM2940CSX-5.0 and Microchip alternatives?

A: The original LM2940CSX-5.0 operates 0°C ~ 125°C. All Microchip alternatives (MIC2937A, MIC2940A, MIC29150, MIC29300 series) operate -40°C ~ 125°C, providing extended low-temperature performance. The Rohm BD50C0AFP2-CE2 also operates -40°C ~ 125°C.

Q: Can I use MIC2937A-5.0WU (750mA) in place of LM2940CSX-5.0 (1A)?

A: Only if your application draws less than 750mA continuous current. The MIC2937A-5.0WU is rated for 750mA maximum output, making it unsuitable for applications requiring the full 1A capability of the original part.

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