KA331 Voltage to Frequency Converter IC - Equivalent & Substitute Parts

Part Overview

The KA331 is a Voltage to Frequency Converter IC operating at 100 kHz with ±0.01% linearity, manufactured by onsemi in an 8-DIP through-hole package. This component has reached obsolete product status, making equivalent substitutes necessary for ongoing design support and production continuity. Texas Instruments manufactures direct functional equivalents within the LM331 and LM231 series that maintain identical electrical specifications and package compatibility.

Substiute Parts

KA331

onsemiIn Stock: 62390KA331 Datasheet

Current PartRFQ

LM331AN/NOPB

Texas InstrumentsIn Stock: 1400LM331AN/NOPB Datasheet

DirectRFQ

LM231AN/NOPB

Texas InstrumentsIn Stock: 5968LM231AN/NOPB Datasheet

SimilarRFQ

LM231N/NOPB

Texas InstrumentsIn Stock: 5317LM231N/NOPB Datasheet

SimilarRFQ

LM331N/NOPB

Texas InstrumentsIn Stock: 33761LM331N/NOPB Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the KA331 is determined by three critical parameters: maximum frequency (100 kHz), linearity specification (±0.01%), and physical package compatibility (8-DIP through-hole). All substitute parts maintain these core electrical and mechanical specifications. The Texas Instruments LM331 and LM231 series satisfy these requirements with identical package footprints and electrical performance.

Substitutes are grouped by temperature stability performance (Full Scale drift specification), which does not affect basic functional compatibility but influences application precision requirements:

• Direct substitutes with enhanced stability: LM331AN/NOPB (±50ppm/°C)
• Functional substitutes with standard stability: LM331N/NOPB and LM231N/NOPB (±150ppm/°C)
• Functional substitute with enhanced stability: LM231AN/NOPB (±50ppm/°C)

Parameter Comparison

Engineering Selection Recommendations

All listed Texas Instruments substitutes are active products with ROHS3 compliance, providing long-term supply assurance compared to the obsolete KA331. Selection between LM331 and LM231 series variants depends on application temperature stability requirements:

For applications requiring enhanced temperature stability, LM331AN/NOPB or LM231AN/NOPB (±50ppm/°C drift) are appropriate selections. For standard precision applications, LM331N/NOPB or LM231N/NOPB (±150ppm/°C drift) provide functional equivalence. All variants maintain identical 100 kHz maximum frequency, ±0.01% linearity, and 8-DIP package compatibility with the original KA331.

Frequently Asked Questions (FAQ)

Q: Can LM331 and LM231 series parts be used interchangeably with KA331?

A: Yes. All listed substitutes maintain the same maximum frequency (100 kHz), linearity specification (±0.01%), and 8-DIP package footprint. Electrical and mechanical compatibility is confirmed across all variants.

Q: What is the difference between LM331 and LM231 series?

A: Both series are voltage to frequency converters with identical core specifications. The primary distinction is temperature stability performance, specified as Full Scale drift. Selection between series should be based on application temperature range requirements.

Q: Does temperature stability (Full Scale drift) affect pin compatibility?

A: No. Temperature stability differences do not affect pinout or package compatibility. All parts use the same 8-DIP through-hole package with identical pin assignments.

Q: Are all substitutes ROHS3 compliant?

A: Yes. All Texas Instruments LM331 and LM231 variants listed are ROHS3 compliant, meeting current environmental and regulatory requirements.

Q: Which substitute has the highest inventory availability?

A: LM331N/NOPB has the highest inventory at 33,700 pieces, followed by LM231AN/NOPB at 5,861 pieces.