LM74CIMX-3 Equivalent & Substitute Parts

Part Overview

The LM74CIMX-3 is a digital temperature sensor manufactured by Texas Instruments, designed for local temperature measurement across a -55°C to 150°C range with 12-bit resolution and SPI output. This component operates on 3V to 5.5V supply voltage and is housed in an 8-SOIC surface mount package. The part is classified as "Not For New Designs," indicating it has been superseded. Identifying equivalent and substitute parts is necessary for legacy system maintenance, design updates, and ensuring continued component availability.

Substiute Parts

LM74CIMX-3

Texas InstrumentsIn Stock: 5477LM74CIMX-3 Datasheet

Current PartRFQ

LM74CIMX-3/NOPB

Texas InstrumentsIn Stock: 1669LM74CIMX-3/NOPB Datasheet

DirectRFQ

TC77-3.3MOA

Microchip TechnologyIn Stock: 1486TC77-3.3MOA Datasheet

MFR RecommendedRFQ

TC77-3.3MOATR

Microchip TechnologyIn Stock: 20112TC77-3.3MOATR Datasheet

MFR RecommendedRFQ

TC77-5.0MOA

Microchip TechnologyIn Stock: 1312TC77-5.0MOA Datasheet

MFR RecommendedRFQ

TC77-5.0MOATR

Microchip TechnologyIn Stock: 1234TC77-5.0MOATR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LM74CIMX-3 is determined by the following critical parameters:

Primary Compatibility Criteria:

• Sensor type: Digital, Local
• Output interface: SPI
• Package type: 8-SOIC surface mount
• Resolution: 12 bits
• Mounting type: Surface mount

Secondary Compatibility Criteria:

• Operating temperature range (must encompass or match the application requirement)
• Supply voltage range (must be compatible with system voltage)
• Accuracy specification (must meet or exceed application tolerance)

The LM74CIMX-3/NOPB is a direct equivalent from Texas Instruments with identical electrical and mechanical specifications but improved compliance status. The TC77 series from Microchip Technology provides functional substitutes with compatible SPI output, 12-bit resolution, and 8-SOIC packaging. The TC77 variants operate across -55°C to 125°C, which covers the primary operating range of most applications using the LM74CIMX-3, though the upper temperature limit is reduced from 150°C to 125°C.

Parameter Comparison

Engineering Selection Recommendations

Direct Replacement (Recommended for Legacy Support): The LM74CIMX-3/NOPB is the preferred substitute for the LM74CIMX-3. It maintains identical electrical specifications and mechanical compatibility while offering ROHS3 compliance and active product status. This part is suitable for direct substitution in existing designs without circuit modification.

Functional Alternatives (Microchip TC77 Series): The TC77-3.3MOA, TC77-3.3MOATR, TC77-5.0MOA, and TC77-5.0MOATR are functionally compatible substitutes from Microchip Technology. These parts share the same SPI interface, 12-bit resolution, 8-SOIC package, and surface mount configuration. All TC77 variants are ROHS3 compliant and carry active product status.

Key Considerations for TC77 Selection:

• Temperature range is limited to -55°C to 125°C, compared to the LM74CIMX-3's -55°C to 150°C. Verify that your application does not require operation above 125°C.
• Supply voltage range is expanded to 2.7V minimum, providing greater flexibility for low-voltage applications.
• Accuracy specification is improved (±1°C vs. ±1.25°C at nominal conditions).
• Packaging options differ: TC77-3.3MOA and TC77-5.0MOA are supplied in tubes; TC77-3.3MOATR and TC77-5.0MOATR are supplied in tape and reel format.
• Moisture sensitivity level varies: TC77-3.3MOA and TC77-5.0MOA have MSL 1 (Unlimited); TC77-3.3MOATR and TC77-5.0MOATR have MSL 3 (168 Hours).

Supply Voltage Designation: The "3.3" and "5.0" designations in TC77 part numbers indicate the nominal supply voltage for which the part is optimized. TC77-3.3 variants are optimized for 3.3V systems; TC77-5.0 variants are optimized for 5V systems. Both operate across the full 2.7V to 5.5V range.

Frequently Asked Questions (FAQ)

Q: Can I use the TC77 series as a direct replacement for the LM74CIMX-3? A: The TC77 series is functionally compatible for most applications. Both use SPI output, 12-bit resolution, and 8-SOIC packaging. However, the TC77 temperature range is limited to -55°C to 125°C. If your application requires operation above 125°C, the LM74CIMX-3/NOPB is the appropriate choice.

Q: What is the difference between TC77-3.3MOA and TC77-5.0MOA? A: Both parts are electrically identical and operate across 2.7V to 5.5V. The designation indicates the nominal supply voltage for optimization. Select based on your system's primary operating voltage. The "MOA" suffix indicates tube packaging; "MOATR" indicates tape and reel packaging.

Q: Is the LM74CIMX-3/NOPB a true equivalent to the LM74CIMX-3? A: Yes. The LM74CIMX-3/NOPB is electrically and mechanically identical to the LM74CIMX-3. The "/NOPB" suffix indicates lead-free, RoHS-compliant construction. This part is the recommended substitute for legacy system maintenance.

Q: What does "Not For New Designs" mean for the LM74CIMX-3? A: This status indicates the part has been superseded and is no longer recommended for new product development. For new designs, use the LM74CIMX-3/NOPB or the TC77 series from Microchip Technology.

Q: Are all substitute parts RoHS compliant? A: The LM74CIMX-3 is RoHS non-compliant. The LM74CIMX-3/NOPB and all TC77 variants are ROHS3 compliant. If RoHS compliance is required, select from the compliant alternatives.

Q: How do I choose between tube and tape & reel packaging for TC77 parts? A: Tube packaging (MOA) is suitable for lower-volume applications and manual assembly. Tape and reel packaging (MOATR) is designed for high-volume automated assembly. Select based on your production volume and assembly process.

Q: What is the difference in accuracy between the LM74CIMX-3 and TC77 series? A: The LM74CIMX-3 specifies ±1.25°C accuracy at nominal conditions and ±5°C across the full operating range. The TC77 series specifies ±1°C accuracy at nominal conditions and ±3°C across the full operating range. The TC77 offers improved accuracy.