LM66CIM-RLSKB Equivalent & Substitute Parts

Part Overview

The LM66CIM-RLSKB is a thermostat temperature sensor manufactured by Texas Instruments, designed for thermal management applications requiring dual-threshold switching at 73°C and 82°C. The device features active low open collector output and operates across a supply voltage range of 2.7V to 10V with a maximum supply current of 250µA. The product is classified as obsolete, necessitating identification of functionally equivalent alternatives for ongoing design requirements and component procurement.

Substiute Parts

LM66CIM-RLSKB

Texas InstrumentsIn Stock: 1027LM66CIM-RLSKB Datasheet

Current PartRFQ

LM56CIM/NOPB

Texas InstrumentsIn Stock: 24015LM56CIM/NOPB Datasheet

MFR RecommendedRFQ

AD7416ARZ

Analog Devices Inc.In Stock: 17809AD7416ARZ Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the LM66CIM-RLSKB is determined by the following critical parameters:

Mechanical Compatibility: All substitute parts must use the 8-SOIC surface mount package to ensure direct PCB footprint compatibility without layout modifications.

Thermal Operating Range: Substitute parts must support the full -40°C to 125°C operating temperature range to maintain functional equivalence across all environmental conditions.

Supply Voltage Compatibility: The substitute must operate within or encompass the 2.7V to 10V supply voltage range of the original part.

Accuracy Specification: Thermal accuracy must be ±3°C or better to maintain measurement reliability equivalent to the original device.

The LM56CIM/NOPB and AD7416ARZ meet these mechanical and thermal requirements. However, they differ in output architecture and functional implementation, requiring application-level evaluation for direct substitution feasibility.

Parameter Comparison

Engineering Selection Recommendations

LM56CIM/NOPB: This Texas Instruments substitute maintains identical package geometry and thermal operating range. It achieves ROHS3 compliance, addressing regulatory requirements unmet by the obsolete LM66CIM-RLSKB. However, the LM56CIM/NOPB outputs analog voltage rather than discrete switching signals, requiring circuit redesign if the original application depends on open collector threshold switching. The product remains obsolete, limiting long-term availability.

AD7416ARZ: This Analog Devices temperature sensor provides active product status, ensuring sustained component availability and manufacturing support. It meets ROHS3 compliance and delivers superior accuracy (±2°C typical). The device operates within a reduced supply voltage range (2.7V to 5.5V), which is compatible with the original 2.7V to 10V specification at the lower end. The AD7416ARZ implements I2C digital output with programmable limits and shutdown mode, fundamentally altering the circuit interface from the original open collector design. This substitution requires firmware or microcontroller integration to replicate the original thermostat functionality.

For applications requiring direct functional equivalence with minimal circuit modification, neither substitute provides a true drop-in replacement due to output architecture differences. Selection depends on whether the application can accommodate analog voltage or I2C digital output in place of open collector switching.

Frequently Asked Questions (FAQ)

Q: Can the LM56CIM/NOPB directly replace the LM66CIM-RLSKB without circuit changes?

A: No. While both devices share the 8-SOIC package and identical thermal operating range, the LM56CIM/NOPB outputs analog voltage (6.2mV/°C) rather than open collector switching signals. Applications relying on discrete threshold detection require analog-to-digital conversion or comparator circuits to replicate the original switching behavior.

Q: Is the AD7416ARZ compatible with the original 10V supply voltage specification?

A: The AD7416ARZ operates within 2.7V to 5.5V supply range, which does not encompass the original 10V maximum. Applications using 5.5V or lower supply voltages can use this substitute. Designs requiring 10V operation must retain the original part or select an alternative with extended voltage rating.

Q: What are the package compatibility requirements for substitution?

A: All three devices use the 8-SOIC surface mount package with identical 0.154" (3.90mm) width. PCB footprints are mechanically compatible without layout modification. Pin assignments must be verified against specific application schematics, as functional pin definitions differ between open collector, analog, and I2C output architectures.

Q: Why is the LM66CIM-RLSKB obsolete, and what does this mean for procurement?

A: Obsolete status indicates Texas Instruments has discontinued manufacturing and support. Existing inventory may be available through authorized distributors, but long-term supply is not guaranteed. The AD7416ARZ, with active product status, provides sustained availability and manufacturing support for new designs.

Q: How do accuracy specifications compare across the three devices?

A: The LM66CIM-RLSKB and LM56CIM/NOPB both specify ±3°C accuracy. The AD7416ARZ achieves ±2°C typical accuracy with ±3°C maximum, providing superior thermal measurement precision. All three devices meet the ±3°C threshold required for equivalent thermal management performance.

Q: What compliance differences exist between these temperature sensors?

A: The LM66CIM-RLSKB is RoHS non-compliant. Both the LM56CIM/NOPB and AD7416ARZ achieve ROHS3 compliance, meeting current environmental and regulatory requirements. All three devices are REACH unaffected and classified as EAR99 for export control purposes.