LM4128AMFX-2.5 Equivalent & Substitute Parts

Part Overview

The LM4128AMFX-2.5 is a Series Voltage Reference IC from Texas Instruments, delivering a fixed 2.5V output with ±0.1% tolerance in a SOT-23-5 surface mount package. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity. The part operates across a -40°C to 125°C temperature range with 20 mA output current capability and is suitable for precision analog applications requiring stable voltage references.

Substiute Parts

LM4128AMFX-2.5

Texas InstrumentsIn Stock: 795LM4128AMFX-2.5 Datasheet

Current PartRFQ

LM4128AMFX-2.5/NOPB

Texas InstrumentsIn Stock: 1116LM4128AMFX-2.5/NOPB Datasheet

DirectRFQ

LM4128AMF-2.5/NOPB

National SemiconductorIn Stock: 2362LM4128AMF-2.5/NOPB Datasheet

Parametric EquivalentRFQ

LM4128AQ1MF2.5/NOPB

National SemiconductorIn Stock: 2428LM4128AQ1MF2.5/NOPB Datasheet

Parametric EquivalentRFQ

LM4128AQ1MFX2.5/NOPB

Texas InstrumentsIn Stock: 1930LM4128AQ1MFX2.5/NOPB Datasheet

Parametric EquivalentRFQ

MAX6037AAUK25+T

Analog Devices Inc./Maxim IntegratedIn Stock: 5028MAX6037AAUK25+T Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the LM4128AMFX-2.5 is determined by the following critical parameters:

• Fixed output voltage of 2.5V
• Output current capability of 20 mA
• Voltage tolerance of ±0.1%
• Input voltage range of 2.9V ~ 5.5V
• Operating temperature range of -40°C ~ 125°C
• SOT-23-5 surface mount package
• Series voltage reference topology

Substitute parts are grouped into three categories based on their relationship to the main part:

Direct Manufacturer Equivalent: LM4128AMFX-2.5/NOPB maintains identical electrical specifications and packaging, with the primary distinction being active product status and RoHS3 compliance.

Parametric Equivalents: LM4128AMF-2.5/NOPB, LM4128AQ1MF2.5/NOPB, and LM4128AQ1MFX2.5/NOPB share all critical electrical parameters and package specifications. Variations include manufacturer designation, packaging format (Bulk vs. Tape & Reel), and automotive qualification (AEC-Q100).

Manufacturer Recommended Alternative: MAX6037AAUK25+T from Analog Devices Inc./Maxim Integrated provides functional equivalence with modified electrical characteristics: ±0.2% tolerance, 5 mA output current, and improved temperature coefficient (25ppm/°C vs. 75ppm/°C). This part is suitable for applications where the relaxed tolerance and lower output current are acceptable.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement: LM4128AMFX-2.5/NOPB is the primary choice, offering identical electrical and mechanical specifications with active product status and RoHS3 compliance. This part eliminates obsolescence risk while maintaining full design compatibility.

For LM4128 Series Continuity: LM4128AMF-2.5/NOPB and LM4128AQ1MF2.5/NOPB provide parametric equivalence within the LM4128 family. LM4128AQ1MFX2.5/NOPB adds automotive-grade qualification (AEC-Q100) for applications requiring automotive reliability standards.

For Alternative Topology: MAX6037AAUK25+T from Analog Devices Inc./Maxim Integrated is suitable when relaxed tolerance (±0.2% vs. ±0.1%) and reduced output current (5 mA vs. 20 mA) are acceptable. This part offers superior noise performance (14µVp-p vs. 275µVp-p) and improved temperature coefficient (25ppm/°C vs. 75ppm/°C), making it advantageous for low-noise precision applications with lower current demands.

All substitute parts maintain SOT-23-5 package compatibility and operate across the -40°C to 125°C temperature range. Selection should account for compliance requirements (RoHS3), automotive qualification needs (AEC-Q100), and specific electrical performance criteria of the target application.

Frequently Asked Questions (FAQ)

Q: Can LM4128AMFX-2.5/NOPB be used as a direct drop-in replacement for the obsolete LM4128AMFX-2.5?

A: Yes. LM4128AMFX-2.5/NOPB maintains identical electrical specifications, tolerance, temperature coefficient, noise characteristics, and SOT-23-5 packaging. The primary differences are active product status and RoHS3 compliance, making it a direct functional equivalent.

Q: What are the key differences between the LM4128 variants (LM4128AMF-2.5/NOPB, LM4128AQ1MF2.5/NOPB, LM4128AQ1MFX2.5/NOPB)?

A: All three variants share identical electrical parameters (2.5V output, ±0.1% tolerance, 20 mA output current, 75ppm/°C temperature coefficient). Differences include manufacturer designation (National Semiconductor vs. Texas Instruments), packaging format (Bulk vs. Tape & Reel), and automotive qualification status. LM4128AQ1MF2.5/NOPB and LM4128AQ1MFX2.5/NOPB carry AEC-Q100 automotive qualification.

Q: Is MAX6037AAUK25+T a suitable replacement for the LM4128AMFX-2.5?

A: MAX6037AAUK25+T provides functional equivalence with modified electrical characteristics. It maintains the 2.5V fixed output and SOT-23-5 package but differs in tolerance (±0.2% vs. ±0.1%), output current (5 mA vs. 20 mA), temperature coefficient (25ppm/°C vs. 75ppm/°C), and noise performance (14µVp-p vs. 275µVp-p). Use this part only when the relaxed tolerance and lower output current specifications are compatible with your application requirements.

Q: Are all substitute parts RoHS3 compliant?

A: LM4128AMFX-2.5/NOPB and LM4128AQ1MFX2.5/NOPB are explicitly RoHS3 compliant. MAX6037AAUK25+T is also RoHS3 compliant. LM4128AMF-2.5/NOPB and LM4128AQ1MF2.5/NOPB do not specify RoHS status in the provided data.

Q: Which substitute part is recommended for automotive applications?

A: LM4128AQ1MF2.5/NOPB and LM4128AQ1MFX2.5/NOPB carry AEC-Q100 automotive qualification. These parts are suitable for automotive-grade designs requiring formal qualification documentation.

Q: Can I use a substitute part with different output current specifications?

A: Output current capability must match or exceed your circuit requirements. MAX6037AAUK25+T provides 5 mA output current compared to 20 mA for the LM4128 variants. Use MAX6037AAUK25+T only if your application requires 5 mA or less.

Q: Are all substitute parts available in the same package?

A: Yes. All substitute parts use the SOT-23-5 package (SC-74A, SOT-753 case), ensuring mechanical and electrical compatibility with the original LM4128AMFX-2.5 footprint.