LF351N Equivalent & Substitute Parts

Part Overview

The LF351N is a J-FET operational amplifier manufactured by STMicroelectronics, housed in an 8-DIP through-hole package. This single-circuit amplifier is designed for applications requiring low input bias current and high input impedance characteristics typical of J-FET input stages. The LF351N is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and component procurement.

Substiute Parts

LF351N

STMicroelectronicsIn Stock: 2497LF351N Datasheet

Current PartRFQ

LF356N/NOPB

Texas InstrumentsIn Stock: 17519LF356N/NOPB Datasheet

SimilarRFQ

TL071CP

Texas InstrumentsIn Stock: 22310TL071CP Datasheet

SimilarRFQ

TL081ACP

Texas InstrumentsIn Stock: 4337TL081ACP Datasheet

SimilarRFQ

TL081BCP

Texas InstrumentsIn Stock: 2204TL081BCP Datasheet

SimilarRFQ

TL081CP

Texas InstrumentsIn Stock: 88939TL081CP Datasheet

SimilarRFQ

TL081IP

Texas InstrumentsIn Stock: 2471TL081IP Datasheet

SimilarRFQ

TLE2071CP

Texas InstrumentsIn Stock: 3199TLE2071CP Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LF351N is determined by strict adherence to the following electrical and mechanical parameters:

Critical Matching Parameters:

• Amplifier Type: J-FET input configuration
• Number of Circuits: Single circuit (1)
• Package / Case: 8-DIP (0.300", 7.62mm)
• Mounting Type: Through Hole
• Operating Temperature Range: 0°C to 70°C minimum
• Voltage - Supply Span: Minimum 6V to maximum 32V overlap required

Functional Compatibility Parameters:

• Slew Rate: 12 V/µs or greater
• Gain Bandwidth Product: 3 MHz or greater
• Current - Input Bias: 65 pA or lower
• Voltage - Input Offset: 3 mV or lower
• Current - Supply: 5 mA or lower
• Current - Output / Channel: 40 mA or greater

Substitute parts must satisfy all critical matching parameters and maintain functional compatibility within the specified ranges. Parts that exceed these boundaries are included only when they provide superior performance characteristics without introducing incompatibility.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Direct Compatibility):

The TL081CP, TL081ACP, and TL081BCP from Texas Instruments provide the most direct substitution for the LF351N. These parts maintain identical supply current (1.4 mA), matching package configuration, and overlapping supply voltage ranges (7V to 36V). All three are active products with ROHS3 compliance. The TL081CP offers the highest inventory availability (88,892 units) and is recommended as the primary substitute for new designs and ongoing production.

Secondary Substitutes (Enhanced Performance):

The TL071CP provides superior gain bandwidth product (5.25 MHz versus 4 MHz) and maintains functional compatibility across all critical parameters. This part is suitable for applications requiring improved frequency response while maintaining the same package and mounting configuration.

The LF356N/NOPB from Texas Instruments offers higher gain bandwidth product (5 MHz) and is part of the BI-FET™ series. However, this part specifies a fixed supply voltage span of 30V, which differs from the LF351N's 6V to 32V range. This part is suitable only for applications operating at 30V supply.

Enhanced Performance Substitute:

The TLE2071CP represents an enhanced alternative with superior electrical characteristics: 45 V/µs slew rate, 10 MHz gain bandwidth product, and 490 µV input offset voltage. This part maintains the same 8-DIP package and through-hole mounting. The TLE2071CP is part of the Excalibur™ series and is suitable for applications requiring higher performance specifications while maintaining backward compatibility with the LF351N footprint.

Temperature-Extended Substitute:

The TL081IP extends the operating temperature range to -40°C to 85°C, providing broader environmental coverage compared to the LF351N's 0°C to 70°C range. This part is suitable for applications requiring extended temperature operation.

All substitute parts are ROHS3 compliant and REACH unaffected, maintaining regulatory compliance equivalent to the original LF351N.

Frequently Asked Questions (FAQ)

Q: Can the TL081CP directly replace the LF351N in existing designs?

A: Yes. The TL081CP maintains identical package configuration (8-DIP through-hole), matching supply current (1.4 mA), and overlapping supply voltage range (7V to 36V encompasses the LF351N's 6V to 32V range). Pin-for-pin compatibility is maintained. The TL081CP is active and widely available.

Q: What is the difference between TL081CP, TL081ACP, and TL081BCP?

A: All three are TL081 variants with identical electrical specifications except for input offset voltage. The TL081BCP specifies 2 mV input offset voltage, while TL081CP and TL081ACP specify 3 mV. All three maintain the same slew rate (13 V/µs), gain bandwidth product (3 MHz), and supply current (1.4 mA). Selection depends on offset voltage requirements for the specific application.

Q: Why does the LF356N/NOPB show a fixed 30V supply span?

A: The LF356N/NOPB specifies minimum and maximum supply voltage both at 30V, indicating operation at a fixed supply voltage rather than a range. This differs from the LF351N's 6V to 32V operating range. The LF356N/NOPB is suitable only for applications designed for 30V supply operation.

Q: Is the TLE2071CP a suitable substitute for all LF351N applications?

A: The TLE2071CP is pin-compatible and package-compatible with the LF351N. However, its enhanced specifications (45 V/µs slew rate, 10 MHz bandwidth, 490 µV offset) represent performance improvements rather than direct equivalence. Applications sensitive to these parameter changes should evaluate the TLE2071CP's suitability independently. The TLE2071CP is suitable for applications that can benefit from or tolerate these enhanced characteristics.

Q: What is the significance of the TL081IP's extended temperature range?

A: The TL081IP operates from -40°C to 85°C, compared to the LF351N's 0°C to 70°C range. This extended range is suitable for applications requiring operation in wider environmental conditions. All other electrical specifications remain identical to the standard TL081CP.

Q: Are all substitute parts RoHS compliant?

A: Yes. All substitute parts listed are ROHS3 compliant and REACH unaffected, maintaining regulatory compliance equivalent to the LF351N.

Q: Which substitute offers the best inventory availability?

A: The TL081CP offers the highest inventory availability at 88,892 units in stock, followed by TL071CP at 22,300 units. Both are active products suitable for immediate procurement.

Q: Can I use the LF356N/NOPB in a circuit designed for the LF351N?

A: The LF356N/NOPB is pin-compatible and package-compatible. However, the fixed 30V supply specification requires verification that your circuit operates at exactly 30V. If your circuit operates within the LF351N's 6V to 32V range but not at 30V specifically, the LF356N/NOPB is not suitable. Verify supply voltage requirements before substitution.

Q: What is the primary reason for substituting the LF351N?

A: The LF351N is classified as obsolete. Substitute parts are necessary to maintain design continuity, support ongoing production, and ensure long-term component availability. All listed substitutes are active products with established supply chains.