LM4140ACM-2.5 Equivalent & Substitute Parts

Part Overview

The LM4140ACM-2.5 is a series voltage reference IC manufactured by Texas Instruments, delivering a fixed 2.5V output with ±0.1% tolerance. This precision micropower reference is designed for applications requiring stable voltage references in low-power environments. The part is classified as obsolete, making equivalent and substitute parts necessary for new designs and ongoing production support. The 8-SOIC surface mount package provides compact integration for modern electronic assemblies.

Substiute Parts

LM4140ACM-2.5

Texas InstrumentsIn Stock: 3126LM4140ACM-2.5 Datasheet

Current PartRFQ

LM4140ACM-2.5/NOPB

National SemiconductorIn Stock: 1880LM4140ACM-2.5/NOPB Datasheet

DirectRFQ

LTC1798CS8-2.5#PBF

Analog Devices Inc.In Stock: 1938LTC1798CS8-2.5#PBF Datasheet

MFR RecommendedRFQ

LTC1798CS8-2.5#TRPBF

Analog Devices Inc.In Stock: 1998LTC1798CS8-2.5#TRPBF Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the LM4140ACM-2.5 is determined by the following critical parameters:

Primary Substitution Criteria:

• Fixed output voltage of 2.5V
• 8-SOIC surface mount package compatibility
• Operating temperature range of 0°C ~ 70°C
• Input voltage range accommodation (1.8V ~ 5.5V minimum requirement)

Secondary Compatibility Parameters:

• Output current capability (minimum 8 mA)
• Tolerance specification (±0.1% or better)
• Temperature coefficient performance
• Supply current efficiency

The LM4140ACM-2.5/NOPB is a direct equivalent from National Semiconductor with identical electrical specifications and packaging. The LTC1798CS8-2.5 series from Analog Devices Inc. represents a functional substitute with enhanced specifications in certain parameters, though with different input voltage range and supply current characteristics.

Parameter Comparison

Engineering Selection Recommendations

Direct Replacement (Recommended for Pin-Compatible Designs): The LM4140ACM-2.5/NOPB is the preferred direct substitute. It maintains identical electrical specifications and packaging, with the advantage of active product status. This part is suitable for designs requiring no circuit modifications.

Functional Substitute (For Enhanced Performance Requirements): The LTC1798CS8-2.5#PBF and LTC1798CS8-2.5#TRPBF are functionally compatible alternatives from Analog Devices Inc. Both variants offer superior supply current efficiency (8.5 µA versus 375 µA) and higher output current capability (10 mA versus 8 mA). These parts are ROHS3 compliant, addressing environmental compliance requirements that the original part does not meet. The primary trade-offs are reduced tolerance (±0.15% versus ±0.1%) and higher temperature coefficient (40 ppm/°C versus 3 ppm/°C). The input voltage range extends to 12.6V, providing broader application flexibility.

Packaging Consideration: LTC1798CS8-2.5#PBF is supplied in tube packaging, while LTC1798CS8-2.5#TRPBF is supplied in tape and reel format. Selection between these variants depends on production volume and assembly line requirements.

Frequently Asked Questions (FAQ)

Q: Can the LM4140ACM-2.5/NOPB be used as a direct replacement? A: Yes. The LM4140ACM-2.5/NOPB is electrically and mechanically identical to the LM4140ACM-2.5, with the same 8-SOIC package, output voltage, tolerance, and operating specifications. No circuit modifications are required.

Q: What are the key differences between the LM4140 and LTC1798 series? A: The LTC1798 series offers lower supply current (8.5 µA versus 375 µA), higher output current (10 mA versus 8 mA), and extended input voltage range (2.7V ~ 12.6V versus 1.8V ~ 5.5V). The LM4140 provides tighter tolerance (±0.1% versus ±0.15%) and lower temperature coefficient (3 ppm/°C versus 40 ppm/°C).

Q: Are the LTC1798 variants suitable for precision applications? A: The LTC1798 series maintains ±0.15% tolerance, which is acceptable for most applications. However, designs requiring the original ±0.1% tolerance specification should use the LM4140ACM-2.5/NOPB direct equivalent.

Q: What is the difference between LTC1798CS8-2.5#PBF and LTC1798CS8-2.5#TRPBF? A: Both parts are electrically identical. The primary difference is packaging format: #PBF indicates tube packaging, while #TRPBF indicates tape and reel packaging. Selection depends on production volume and assembly equipment compatibility.

Q: Is the LTC1798 series RoHS compliant? A: Yes. The LTC1798CS8-2.5#PBF and LTC1798CS8-2.5#TRPBF are both ROHS3 compliant, addressing environmental and regulatory requirements not met by the original LM4140ACM-2.5.

Q: Can I use the LTC1798 in applications with input voltages below 2.7V? A: No. The LTC1798 series requires a minimum input voltage of 2.7V. For applications requiring operation at 1.8V input, the LM4140ACM-2.5/NOPB direct equivalent must be used.

Q: What is the temperature coefficient impact on circuit performance? A: The LM4140 has a temperature coefficient of 3 ppm/°C, while the LTC1798 has 40 ppm/°C. Over a 70°C operating range, this results in a maximum drift of 0.21mV for the LM4140 and 2.8mV for the LTC1798. Applications with stringent temperature stability requirements should prioritize the lower coefficient specification.