LM45CIM3 Equivalent & Substitute Parts

Part Overview

The LM45CIM3 is an analog local temperature sensor manufactured by Texas Instruments, designed for temperature measurement applications within the -20°C to 100°C range. The device operates with a 10mV/°C output resolution and is housed in a SOT-23-3 surface mount package. This part is classified as obsolete, which necessitates identification of functionally equivalent alternatives for new designs and ongoing production requirements. Substitute parts must maintain compatibility with the SOT-23-3 package format and deliver equivalent or superior performance characteristics across the specified operating parameters.

Substiute Parts

LM45CIM3

Texas InstrumentsIn Stock: 5433LM45CIM3 Datasheet

Current PartRFQ

LM45CIM3/NOPB

Texas InstrumentsIn Stock: 1463LM45CIM3/NOPB Datasheet

DirectRFQ

DS60R+T&R

Analog Devices Inc./Maxim IntegratedIn Stock: 15603DS60R+T&R Datasheet

MFR RecommendedRFQ

MCP9700AT-E/TT

Microchip TechnologyIn Stock: 45486MCP9700AT-E/TT Datasheet

MFR RecommendedRFQ

MCP9700T-E/TT

Microchip TechnologyIn Stock: 99778MCP9700T-E/TT Datasheet

MFR RecommendedRFQ

MCP9701AT-E/TT

Microchip TechnologyIn Stock: 20114MCP9701AT-E/TT Datasheet

MFR RecommendedRFQ

MCP9701T-E/TT

Microchip TechnologyIn Stock: 2326MCP9701T-E/TT Datasheet

MFR RecommendedRFQ

TC1046VNBTR

Microchip TechnologyIn Stock: 1653TC1046VNBTR Datasheet

MFR RecommendedRFQ

TC1047AVNBTR

Microchip TechnologyIn Stock: 38220TC1047AVNBTR Datasheet

MFR RecommendedRFQ

TC1047VNBTR

Microchip TechnologyIn Stock: 6507TC1047VNBTR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LM45CIM3 are selected based on the following critical parameters:

Package Compatibility: All substitutes must use the SOT-23-3 surface mount package to ensure direct board-level compatibility without layout modifications.

Sensor Type: Substitutes must be analog local temperature sensors with analog voltage output to maintain circuit interface compatibility.

Temperature Range Coverage: Substitutes must cover the operational temperature range of the original part. Parts with extended ranges (-40°C ~ 125°C) provide broader application flexibility while remaining backward compatible with -20°C ~ 100°C applications.

Resolution and Output Characteristics: The 10mV/°C resolution of the LM45CIM3 is matched by several substitutes. Parts with alternative resolutions (6.25mV/°C or 19.5mV/°C) require signal conditioning adjustments but remain functionally equivalent for temperature measurement applications.

Supply Voltage Range: Substitutes must operate within compatible supply voltage windows. The LM45CIM3 requires 4V ~ 10V; substitutes with lower minimum voltage requirements (2.3V ~ 5.5V) offer enhanced flexibility.

Accuracy Specifications: Substitutes maintain ±2°C to ±4°C accuracy across their operating ranges, meeting or exceeding the original part's performance.

Compliance Status: Modern substitutes are RoHS3 compliant, addressing regulatory requirements not met by the obsolete LM45CIM3.

Parameter Comparison

Engineering Selection Recommendations

Direct Replacement (Identical Specifications): The LM45CIM3/NOPB is the direct equivalent of the LM45CIM3, maintaining identical electrical and thermal characteristics while providing ROHS3 compliance. This part is the preferred choice for applications requiring no design modifications.

Primary Substitutes (Matched Resolution): The MCP9700AT-E/TT, MCP9700T-E/TT, TC1047AVNBTR, and TC1047VNBTR all provide 10mV/°C resolution matching the original part. These active, ROHS3-compliant devices extend the sensing range to -40°C ~ 125°C and deliver ±2°C accuracy. The MCP9700 series supports lower supply voltages (2.3V minimum), while the TC1047A variant accommodates 2.5V ~ 5.5V operation.

Extended Range Substitutes (Broader Temperature Coverage): The DS60R+T&R and TC1046VNBTR provide full -40°C ~ 125°C coverage with 6.25mV/°C resolution and ±2°C accuracy. These parts require output signal scaling in applications originally designed for 10mV/°C sensors but offer superior low-temperature performance.

High-Resolution Alternatives (Enhanced Sensitivity): The MCP9701AT-E/TT and MCP9701T-E/TT deliver 19.5mV/°C resolution, providing enhanced temperature discrimination. These parts operate across -10°C ~ 125°C with ±2°C to ±4°C accuracy and require output signal conditioning for legacy circuit compatibility.

Compliance Consideration: All recommended substitutes are ROHS3 compliant and active products with established supply chains, addressing the regulatory and obsolescence concerns associated with the original LM45CIM3.

Frequently Asked Questions (FAQ)

Q: Can the LM45CIM3/NOPB be used as a direct drop-in replacement? A: Yes. The LM45CIM3/NOPB maintains identical electrical specifications, package format, and pinout. No circuit modifications are required. This part is the recommended choice for direct substitution.

Q: What is the primary difference between 10mV/°C and 6.25mV/°C resolution sensors? A: Resolution determines output voltage change per degree Celsius. A 10mV/°C sensor produces 10 millivolts of output change per 1°C temperature change, while a 6.25mV/°C sensor produces 6.25 millivolts per degree. Applications using 6.25mV/°C sensors require higher analog-to-digital converter resolution or signal amplification to achieve equivalent temperature discrimination.

Q: Are the MCP9700 and TC1047 series compatible with the original LM45CIM3 circuit? A: Both series are pin-compatible and use identical SOT-23-3 packaging. However, the MCP9700 and TC1047 series extend the sensing range to -40°C ~ 125°C and offer improved accuracy (±2°C). Verify that your application does not require the specific -20°C ~ 100°C range limitation of the original part. Supply voltage compatibility must be confirmed; the MCP9700 series supports 2.3V minimum operation, while the original LM45CIM3 requires 4V minimum.

Q: What supply voltage range should I use for substitutes? A: The original LM45CIM3 requires 4V ~ 10V. Substitutes offer varying ranges: MCP9700 series (2.3V ~ 5.5V), TC1047A (2.5V ~ 5.5V), TC1047V (2.7V ~ 4.4V), and DS60R (2.7V ~ 5.5V). Select a substitute whose supply voltage range encompasses your circuit's operating voltage to ensure compatibility.

Q: Do all substitutes require the same PCB layout? A: Yes. All recommended substitutes use the SOT-23-3 package with identical pin assignments. PCB layout modifications are not required for package compatibility. However, applications using sensors with different resolutions (6.25mV/°C or 19.5mV/°C) may require analog signal conditioning adjustments.

Q: Which substitute offers the best accuracy? A: The DS60R+T&R, MCP9700AT-E/TT, MCP9700T-E/TT, TC1046VNBTR, TC1047AVNBTR, and TC1047VNBTR all deliver ±2°C accuracy at 25°C, which exceeds the original LM45CIM3's ±3°C specification. The MCP9701T-E/TT provides ±4°C accuracy and is suitable for applications with relaxed accuracy requirements.

Q: Is RoHS compliance important for my application? A: The original LM45CIM3 is RoHS non-compliant. All recommended substitutes are ROHS3 compliant, meeting current regulatory requirements for electronic components in most markets. If your application or supply chain mandates RoHS compliance, substitutes are necessary.

Q: Can I use a substitute with a different temperature sensing range? A: Yes, provided the substitute's range encompasses your application's operating temperature. The original LM45CIM3 covers -20°C ~ 100°C. Substitutes with -40°C ~ 125°C ranges are backward compatible and provide extended capability. Substitutes with -10°C ~ 125°C ranges (MCP9701 series) are suitable for applications not requiring sub-zero operation below -10°C.