LM4128CMFX-2.0 Equivalent & Substitute Parts

Part Overview

The LM4128CMFX-2.0 is a Series Voltage Reference IC from Texas Instruments, delivering a fixed 2.048V output with ±0.5% tolerance in a SOT-23-5 surface mount package. This part is classified as Obsolete, making identification of active equivalent and substitute parts essential for ongoing design support and procurement continuity. Equivalent parts maintain identical electrical and mechanical specifications, while substitute parts offer comparable performance within the same functional category.

Substiute Parts

LM4128CMFX-2.0

Texas InstrumentsIn Stock: 2407LM4128CMFX-2.0 Datasheet

Current PartRFQ

LM4128CMFX-2.0/NOPB

Texas InstrumentsIn Stock: 715LM4128CMFX-2.0/NOPB Datasheet

DirectRFQ

LM4128CMF-2.0/NOPB

Texas InstrumentsIn Stock: 2894LM4128CMF-2.0/NOPB Datasheet

Parametric EquivalentRFQ

LM4128CQ1MF2.0/NOPB

Texas InstrumentsIn Stock: 1966LM4128CQ1MF2.0/NOPB Datasheet

Parametric EquivalentRFQ

LM4128CQ1MFX2.0/NOPB

Texas InstrumentsIn Stock: 1074LM4128CQ1MFX2.0/NOPB Datasheet

Parametric EquivalentRFQ

MAX6037AAUK21+T

Analog Devices Inc./Maxim IntegratedIn Stock: 3426MAX6037AAUK21+T Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LM4128CMFX-2.0 are classified based on strict adherence to the following critical parameters:

Electrical Compatibility Criteria:

• Fixed output voltage of 2.048V
• Output tolerance of ±0.5% or better
• Output current capability of 20 mA or greater
• Input voltage range encompassing 2.448V ~ 5.5V
• Operating temperature range of -40°C ~ 125°C or wider
• SOT-23-5 package configuration

Mechanical & Environmental Criteria:

• Surface mount technology
• SC-74A / SOT-753 package footprint
• MSL rating of 1 (Unlimited)
• RoHS compliance status (preferred for new designs)

Substitution Categories:

1. Direct Manufacturer Equivalents – Texas Instruments parts with identical electrical specifications and active product status
2. Parametric Equivalents – Texas Instruments parts meeting all electrical and mechanical requirements, including automotive-grade variants with AEC-Q100 qualification
3. Cross-Manufacturer Alternatives – Parts from other manufacturers meeting or exceeding all specified parameters

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Identical Specifications): LM4128CMFX-2.0/NOPB is the primary direct substitute, maintaining all electrical and mechanical parameters of the obsolete LM4128CMFX-2.0 while offering Active product status and ROHS3 compliance. This part is recommended for designs requiring no circuit modifications.

For New Designs with Enhanced Compliance: LM4128CMF-2.0/NOPB and LM4128CQ1MF2.0/NOPB provide identical electrical performance with Active status and ROHS3 compliance. The LM4128CQ1MF2.0/NOPB and LM4128CQ1MFX2.0/NOPB variants include automotive-grade qualification (AEC-Q100), suitable for applications requiring automotive reliability standards.

For Superior Performance Characteristics: MAX6037AAUK21+T from Analog Devices Inc./Maxim Integrated meets all mechanical and functional requirements while delivering enhanced electrical performance: ±0.2% tolerance (versus ±0.5%), 25 ppm/°C temperature coefficient (versus 100 ppm/°C), and significantly lower noise (11 µVp-p versus 190 µVp-p). This part is suitable for precision applications where improved accuracy and stability are beneficial. Note that output current is reduced to 5 mA; circuit design must accommodate this specification.

Compliance Considerations: All recommended substitutes are ROHS3 compliant, addressing environmental regulatory requirements. The original LM4128CMFX-2.0 is RoHS non-compliant; migration to compliant alternatives is recommended for new procurement.

Frequently Asked Questions (FAQ)

Q: Can LM4128CMFX-2.0/NOPB be used as a direct drop-in replacement for LM4128CMFX-2.0? A: Yes. Both parts share identical electrical specifications (2.048V fixed output, ±0.5% tolerance, 20 mA output current, 100 ppm/°C temperature coefficient) and the same SOT-23-5 package. The primary difference is product status (Active versus Obsolete) and RoHS compliance (ROHS3 versus non-compliant).

Q: What is the difference between LM4128CMF-2.0/NOPB and LM4128CQ1MF2.0/NOPB? A: Both parts are electrically identical. LM4128CQ1MF2.0/NOPB includes automotive-grade qualification (AEC-Q100), making it suitable for automotive applications requiring enhanced reliability testing and qualification. Standard industrial applications can use either variant.

Q: Why does MAX6037AAUK21+T have lower output current (5 mA vs. 20 mA)? A: The MAX6037AAUK21+T is designed for precision reference applications with lower current requirements. If the circuit requires 20 mA output current, this part is not suitable without circuit redesign. For applications requiring only reference voltage with minimal load current, this part offers superior accuracy and noise performance.

Q: Are all substitute parts compatible with the same PCB footprint? A: Yes. All listed parts use the SOT-23-5 package (SC-74A, SOT-753), ensuring identical PCB footprint compatibility. No layout modifications are required for substitution.

Q: Which substitute part should be selected for new automotive designs? A: LM4128CQ1MF2.0/NOPB or LM4128CQ1MFX2.0/NOPB are recommended for automotive applications, as both include AEC-Q100 qualification and maintain all electrical specifications of the original part.

Q: Is RoHS compliance mandatory for all substitute selections? A: RoHS compliance is not mandatory for all applications but is required for products sold in regions with environmental regulations (EU, China, etc.). All recommended substitutes except the original LM4128CMFX-2.0 are ROHS3 compliant.

Q: Can MAX6037AAUK21+T be used in applications requiring 20 mA output current? A: No. The MAX6037AAUK21+T is rated for 5 mA maximum output current. Using it in circuits requiring 20 mA will exceed device specifications and may cause malfunction or damage. Select LM4128 variants for 20 mA applications.