KF351 Equivalent & Substitute Parts

Part Overview

The KF351 is a J-FET operational amplifier manufactured by onsemi, housed in an 8-DIP package for through-hole mounting applications. This device functions as a single-circuit J-FET amplifier with a slew rate of 13V/µs and gain bandwidth product of 4 MHz. The KF351 is classified as obsolete, making identification of equivalent substitute components necessary for ongoing design support, maintenance, and production continuity. Active alternatives with compatible electrical and mechanical specifications are available to ensure system functionality without redesign requirements.

Substiute Parts

KF351

onsemiIn Stock: 1240KF351 Datasheet

Current PartRFQ

TL081ACP

Texas InstrumentsIn Stock: 4337TL081ACP Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the obsolete KF351 with the TL081ACP is based on functional and mechanical compatibility across the following critical parameters:

Electrical Compatibility Criteria:

• Amplifier Type: Both devices are J-FET operational amplifiers
• Number of Circuits: Both contain a single amplifier circuit
• Slew Rate: Identical at 13V/µs, ensuring equivalent transient response
• Operating Temperature Range: Both operate across 0°C to 70°C
• Package / Case: Both use 8-DIP (0.300", 7.62mm) through-hole configuration
• Mounting Type: Both are through-hole mounted

Substitution Feasibility: The TL081ACP meets or exceeds the electrical specifications of the KF351. The gain bandwidth product of the TL081ACP (3 MHz) is lower than the KF351 (4 MHz), but this represents a conservative substitution. Input bias current (30 pA) and input offset voltage (3 mV) are superior in the TL081ACP, indicating improved performance characteristics. Supply current is reduced (1.4mA versus 2.3mA), providing operational efficiency benefits. The TL081ACP is manufactured by Texas Instruments and maintains active product status with full compliance certifications.

Parameter Comparison

Engineering Selection Recommendations

The TL081ACP is the direct substitute for the obsolete KF351 based on the following engineering criteria:

Product Status and Availability: The KF351 is classified as obsolete, whereas the TL081ACP maintains active product status with documented inventory availability. This ensures long-term supply chain reliability and technical support continuity.

Compliance and Regulatory Alignment: Both devices share identical REACH status (REACH Unaffected) and ECCN classification (EAR99). The TL081ACP provides additional compliance assurance through ROHS3 certification, meeting modern environmental and regulatory requirements for new designs and production runs.

Electrical Performance: The TL081ACP delivers equivalent or superior electrical performance across all measured parameters. Identical slew rate (13V/µs) and operating temperature range (0°C to 70°C) ensure functional compatibility. Improved input bias current (30 pA versus 50 pA) and reduced input offset voltage (3 mV versus 5 mV) indicate enhanced precision characteristics. Reduced supply current (1.4mA versus 2.3mA) provides power efficiency benefits without functional compromise.

Mechanical and Package Compatibility: Both devices utilize identical 8-DIP (0.300", 7.62mm) through-hole packaging, enabling direct socket substitution without PCB redesign or layout modifications.

Frequently Asked Questions (FAQ)

Q: Can the TL081ACP be used as a direct replacement for the KF351 without circuit modifications?

A: Yes. The TL081ACP is mechanically and electrically compatible with the KF351. Both devices share identical 8-DIP through-hole packaging, slew rate (13V/µs), and operating temperature range (0°C to 70°C). The TL081ACP can be inserted into existing KF351 sockets without PCB alterations. Electrical performance of the TL081ACP meets or exceeds KF351 specifications.

Q: What are the key differences between the KF351 and TL081ACP?

A: The primary differences are product status and electrical refinements. The KF351 is obsolete; the TL081ACP is active. The TL081ACP exhibits lower input bias current (30 pA versus 50 pA), lower input offset voltage (3 mV versus 5 mV), and reduced supply current (1.4mA versus 2.3mA). The gain bandwidth product of the TL081ACP (3 MHz) is lower than the KF351 (4 MHz), but this does not affect substitution feasibility for standard applications.

Q: Are there any supply voltage differences between these devices?

A: The TL081ACP specifies a supply voltage span of 7V to 36V. The KF351 does not provide explicit supply voltage specifications in the available documentation. Both devices operate within the 0°C to 70°C temperature range. Verify supply voltage requirements for your specific application circuit.

Q: What is the significance of the 8-DIP package designation?

A: The 8-DIP (Dual In-line Package) with 0.300" (7.62mm) row spacing is a standard through-hole package format. Both the KF351 and TL081ACP use this identical package, ensuring mechanical compatibility and direct socket substitution capability without PCB redesign.

Q: Does the TL081ACP meet current regulatory and compliance standards?

A: Yes. The TL081ACP is ROHS3 compliant and maintains REACH Unaffected status, meeting current environmental and regulatory requirements. The KF351 shares REACH Unaffected status but does not specify RoHS compliance, reflecting its obsolete classification.

Q: What inventory considerations should be evaluated?

A: The KF351 has 1211 pieces in stock (new original). The TL081ACP has 4300 pieces in stock (new original). The TL081ACP provides superior long-term availability and supply chain security due to its active product status and higher inventory levels.