EF10 Trimmer Capacitor Equivalent & Substitute Parts

Part Overview

The EF10 is a 0.8–10pF trimmer capacitor manufactured by Knowles Voltronics, designed for through-hole mounting applications requiring top adjustment. This component features a polytetrafluoroethylene (PTFE) dielectric and operates across a temperature range of –65°C to 125°C at a rated voltage of 250V.

The EF10 is classified as obsolete. Identifying equivalent and substitute parts is necessary to maintain design continuity and ensure component availability for production, repair, and field service applications.

Substiute Parts

EF10

Knowles VoltronicsIn Stock: 758EF10 Datasheet

Current PartRFQ

AF10

Knowles VoltronicsIn Stock: 907AF10 Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the EF10 is based on the following critical parameters that must remain consistent or compatible:

• Capacitance Range Overlap: The substitute must cover or encompass the required tuning range within the application circuit.
• Voltage Rating: The substitute must meet or exceed the 250V rated voltage requirement.
• Adjustment Type: Top adjustment is required to maintain mechanical compatibility with existing designs.
• Mounting Type: Through-hole mounting must be preserved for PCB compatibility.
• Physical Dimensions: The 0.300" diameter and 0.480" maximum seated height must be maintained to ensure mechanical fit.
• Operating Temperature Range: The substitute must support the –65°C to 125°C operating window.
• Q Factor: A Q value of 5000 @ 100MHz indicates low-loss performance suitable for RF and precision tuning applications.

The AF10 is identified as a direct substitute based on these parameters.

Parameter Comparison

Engineering Selection Recommendations

The AF10 is a direct substitute for the EF10 based on electrical and mechanical parameter alignment. Key considerations:

• Capacitance Range: The AF10 capacitance range (1–10pF) is a subset of the EF10 range (0.8–10pF). The AF10 is suitable for applications where the minimum required capacitance is 1pF or greater. Applications requiring tuning below 1pF cannot use the AF10 as a substitute.
• Dielectric Material: The EF10 uses PTFE dielectric, while the AF10 uses air dielectric. Both materials are suitable for low-loss RF and precision tuning applications. The air dielectric in the AF10 may offer slightly different temperature stability characteristics; circuit validation is appropriate for critical applications.
• Product Status: The AF10 is active and in production, ensuring long-term availability. The EF10 is obsolete, making the AF10 the recommended path for new designs and ongoing production support.
• Compliance: The AF10 is RoHS3 compliant and REACH unaffected, meeting modern regulatory requirements.

Frequently Asked Questions (FAQ)

Q: Can the AF10 replace the EF10 in all applications?

A: The AF10 is a suitable substitute provided the application does not require capacitance tuning below 1pF. If the circuit design requires adjustment in the 0.8–1pF range, the AF10 cannot be used as a direct substitute.

Q: What is the difference between PTFE and air dielectric in these trimmer capacitors?

A: Both PTFE and air dielectrics are suitable for low-loss RF applications. PTFE offers mechanical stability and environmental protection, while air dielectric provides excellent temperature stability and low loss. The choice depends on circuit requirements; both materials support the specified Q factor of 5000 @ 100MHz.

Q: Are the physical dimensions identical between EF10 and AF10?

A: Yes. Both parts share identical dimensions: 0.300" diameter and 0.480" maximum seated height. They are mechanically interchangeable in through-hole PCB layouts.

Q: Is the AF10 available in the same packaging as the EF10?

A: The AF10 is supplied in bulk packaging, whereas the EF10 packaging specification was not provided. Confirm packaging requirements with your procurement or supply chain team.

Q: What compliance certifications does the AF10 carry?

A: The AF10 is RoHS3 compliant and REACH unaffected, meeting current regulatory standards for electronic components in most markets.