LM331AN Equivalent & Substitute Parts

Part Overview

The LM331AN is a Voltage to Frequency Converter IC manufactured by Texas Instruments, designed for precision analog-to-digital conversion applications requiring frequency output. This component operates at a maximum frequency of 100 kHz with linearity of ±0.01% and temperature stability of ±50ppm/°C. The LM331AN is classified as obsolete, which necessitates identification of active equivalent parts to ensure continued design support and procurement availability for new production runs and maintenance applications.

Substiute Parts

LM331AN

Texas InstrumentsIn Stock: 10611LM331AN Datasheet

Current PartRFQ

LM331AN/NOPB

Texas InstrumentsIn Stock: 1400LM331AN/NOPB Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LM331AN is determined by strict equivalence across the following critical parameters:

• Functional Type: Voltage to Frequency Converter
• Frequency Range: 100 kHz maximum operating frequency
• Electrical Performance: ±0.01% linearity and ±50ppm/°C temperature coefficient
• Package Compatibility: 8-DIP (0.300", 7.62mm) through-hole mounting
• Pin Configuration: Identical pinout and signal assignments

The LM331AN/NOPB qualifies as a direct substitute based on identical electrical specifications, package form factor, and pin compatibility. The primary distinction is product status and compliance certification, with the /NOPB variant representing the active production equivalent.

Parameter Comparison

Engineering Selection Recommendations

The LM331AN/NOPB is the direct active equivalent for the obsolete LM331AN. Both parts maintain identical electrical performance specifications and physical package dimensions, ensuring drop-in compatibility in existing circuit designs.

For new designs and procurement, the LM331AN/NOPB is the appropriate selection due to its active product status and ROHS3 compliance certification. This variant eliminates supply chain discontinuity risks associated with obsolete components while maintaining full electrical and mechanical compatibility.

For applications subject to RoHS regulatory requirements, the LM331AN/NOPB satisfies ROHS3 compliance, whereas the original LM331AN does not. The /NOPB designation indicates lead-free solder ball construction, aligning with modern manufacturing standards.

Frequently Asked Questions (FAQ)

Q: Can the LM331AN/NOPB be used as a direct replacement for the LM331AN?

A: Yes. The LM331AN/NOPB is electrically and mechanically identical to the LM331AN. Both parts feature the same 100 kHz maximum frequency, ±0.01% linearity, ±50ppm/°C temperature coefficient, and 8-DIP package configuration. The /NOPB variant is the active production equivalent.

Q: What is the difference between LM331AN and LM331AN/NOPB?

A: The primary differences are product status and compliance certification. The LM331AN is obsolete and RoHS non-compliant, while the LM331AN/NOPB is active and ROHS3 compliant. Electrical specifications and package form factor are identical.

Q: Are there any pinout differences between these parts?

A: No. Both the LM331AN and LM331AN/NOPB use the same 8-DIP package with identical pin assignments and signal definitions. No circuit board modifications are required for substitution.

Q: What does the /NOPB suffix indicate?

A: The /NOPB designation indicates lead-free solder ball construction, compliant with RoHS3 regulations. This marking distinguishes the part from legacy lead-containing versions.

Q: Is the LM331AN/NOPB available in different packaging options?

A: The LM331AN/NOPB is supplied in Tube packaging. The original LM331AN packaging specification was not provided in the technical data.