LM4128DMFX-3.3 Equivalent & Substitute Parts

Part Overview

The LM4128DMFX-3.3 is a Series Voltage Reference IC from Texas Instruments, providing a fixed 3.3V output with ±1% tolerance in a SOT-23-5 surface mount package. This part is classified as Obsolete, making equivalent and substitute parts necessary for new designs and ongoing production requirements. The device is designed for power management applications requiring stable voltage reference outputs with low supply current consumption.

Substiute Parts

LM4128DMFX-3.3

Texas InstrumentsIn Stock: 891LM4128DMFX-3.3 Datasheet

Current PartRFQ

LM4128DMFX-3.3/NOPB

Texas InstrumentsIn Stock: 902LM4128DMFX-3.3/NOPB Datasheet

DirectRFQ

LM4128DMF-3.3/NOPB

Texas InstrumentsIn Stock: 4072LM4128DMF-3.3/NOPB Datasheet

Parametric EquivalentRFQ

LM4128DQ1MF3.3/NOPB

Texas InstrumentsIn Stock: 3010LM4128DQ1MF3.3/NOPB Datasheet

Parametric EquivalentRFQ

LM4128DQ1MFX3.3/NOPB

Texas InstrumentsIn Stock: 851LM4128DQ1MFX3.3/NOPB Datasheet

Parametric EquivalentRFQ

MAX6037AAUK33+T

Analog Devices Inc./Maxim IntegratedIn Stock: 3575MAX6037AAUK33+T Datasheet

MFR RecommendedRFQ

MAX6037BAUK33+T

Analog Devices Inc./Maxim IntegratedIn Stock: 1044MAX6037BAUK33+T Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LM4128DMFX-3.3 are categorized based on electrical and mechanical compatibility. The primary substitution criteria are:

Critical Parameters for Substitution:

• Fixed output voltage of 3.3V
• SOT-23-5 package compatibility
• Surface mount mounting type
• Operating temperature range of -40°C to 125°C
• Input voltage range of 3.7V to 5.5V or compatible range

Substitution Categories:

Direct Manufacturer Equivalents (Texas Instruments LM4128 Series): Parts with identical electrical specifications and packaging, differing only in product status or packaging format (Tape & Reel vs. bulk).

Parametric Equivalents (Texas Instruments LM4128 Series with Automotive Grade): Parts with identical core electrical specifications but qualified for automotive applications (AEC-Q100), providing enhanced reliability for demanding environments.

Manufacturer Recommended Alternatives (Analog Devices MAX6037 Series): Parts from alternative manufacturers with the same 3.3V fixed output and SOT-23-5 package, offering improved tolerance and temperature coefficient specifications at the cost of reduced output current capability.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement in Active Production:

Use LM4128DMFX-3.3/NOPB or LM4128DMF-3.3/NOPB. These parts maintain identical electrical specifications and packaging to the obsolete LM4128DMFX-3.3 while offering Active product status and ROHS3 compliance. The primary difference is packaging format (Tape & Reel vs. bulk). LM4128DMF-3.3/NOPB offers higher inventory availability (3995 Pcs) compared to LM4128DMFX-3.3/NOPB (868 Pcs).

For Automotive Applications:

Use LM4128DQ1MF3.3/NOPB or LM4128DQ1MFX3.3/NOPB. These variants maintain identical electrical specifications while providing AEC-Q100 automotive qualification. Selection between these two depends on packaging requirements and inventory availability.

For Enhanced Performance Requirements:

Use MAX6037AAUK33+T or MAX6037BAUK33+T from Analog Devices Inc./Maxim Integrated. These alternatives offer superior tolerance (±0.2% and ±0.3% respectively versus ±1%), lower temperature coefficient (25 ppm/°C and 50 ppm/°C respectively versus 100 ppm/°C), and significantly lower noise performance (19 µVp-p versus 310 µVp-p). However, output current is reduced to 5 mA and supply current increases to 275 µA. These parts are suitable for applications where output current demand does not exceed 5 mA and improved voltage stability is required.

Compliance Considerations:

All substitute parts except the original LM4128DMFX-3.3 are ROHS3 compliant. For new designs or production requiring RoHS compliance, any of the substitute parts are acceptable. The original part's RoHS non-compliance status makes it unsuitable for applications with regulatory compliance requirements.

Frequently Asked Questions (FAQ)

Q: Can LM4128DMFX-3.3/NOPB be used as a direct replacement for LM4128DMFX-3.3?

A: Yes. LM4128DMFX-3.3/NOPB is electrically and mechanically identical to the obsolete LM4128DMFX-3.3. The primary differences are Active product status and ROHS3 compliance. The "/NOPB" suffix indicates lead-free packaging, which is standard for current production.

Q: What is the difference between LM4128DMFX-3.3/NOPB and LM4128DMF-3.3/NOPB?

A: Both parts are electrically identical with the same specifications. The difference is in the part number nomenclature and packaging format. LM4128DMF-3.3/NOPB has higher inventory availability and is recommended for new orders.

Q: When should I use the automotive-qualified variants (LM4128DQ1MF3.3/NOPB or LM4128DQ1MFX3.3/NOPB)?

A: Use automotive-qualified variants when the application requires AEC-Q100 certification or operates in automotive environments. These parts maintain identical electrical specifications to the standard variants while providing enhanced reliability qualification.

Q: Can MAX6037AAUK33+T replace LM4128DMFX-3.3 in all applications?

A: MAX6037AAUK33+T is electrically compatible for the 3.3V fixed output and SOT-23-5 package. However, the reduced output current (5 mA versus 20 mA) and increased supply current (275 µA versus 100 µA) must be evaluated against application requirements. Use MAX6037AAUK33+T only when output current demand does not exceed 5 mA.

Q: What are the key differences between MAX6037AAUK33+T and MAX6037BAUK33+T?

A: Both parts are from Analog Devices Inc./Maxim Integrated with identical output current (5 mA) and supply current (275 µA). The differences are tolerance (±0.2% versus ±0.3%) and temperature coefficient (25 ppm/°C versus 50 ppm/°C). MAX6037AAUK33+T offers tighter tolerance and lower temperature coefficient for applications requiring superior voltage stability.

Q: Are all substitute parts RoHS compliant?

A: All substitute parts listed are ROHS3 compliant. The original LM4128DMFX-3.3 is RoHS non-compliant. For new designs or production requiring RoHS compliance, use any of the substitute parts.

Q: What is the difference between SOT-23-5 and SC-74A packaging?

A: SOT-23-5 and SC-74A refer to the same physical package format. SC-74A is the JEDEC designation, while SOT-23-5 is the industry common name. All listed parts use this identical package.

Q: Can I use these parts interchangeably on the same PCB?

A: Yes, all listed parts use the SOT-23-5 package with identical pinout and footprint. They are mechanically and electrically interchangeable on the same PCB, provided the application requirements (output current, tolerance, temperature coefficient) are met by the selected substitute.