GSX366 Trimmer Capacitor Equivalent & Substitute Parts

Part Overview

The GSX366 is a 1–20pF trimmer capacitor rated at 100V with top surface mount adjustment, manufactured by Sprague-Goodman under the FILMTRIM® series. This component is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing design support and production continuity. The GSX366 employs polytetrafluoroethylene (PTFE) dielectric material in a low-profile surface mount package measuring 7.20mm × 5.40mm with a maximum seated height of 2.60mm. Substitution is necessary to maintain supply chain reliability and ensure component availability for legacy system maintenance and new production builds.

Substiute Parts

GSX366

Sprague-GoodmanIn Stock: 1119GSX366 Datasheet

Current PartRFQ

JZ200

Knowles VoltronicsIn Stock: 141557JZ200 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the GSX366 is based on the following critical parameters that define functional equivalence:

Capacitance Range Overlap: The GSX366 operates within 1–20pF. A substitute must support the full operational range required by the circuit or at minimum cover the upper capacitance values (15–20pF range) where the GSX366 is typically used.

Voltage Rating: The GSX366 is rated at 100V. Substitutes must meet or exceed this voltage specification to ensure safe operation under maximum circuit stress conditions.

Adjustment Type: Both the main part and substitute must feature top-side adjustment to maintain mechanical compatibility with existing tuning mechanisms and PCB layouts.

Mounting Configuration: Surface mount technology is mandatory. The substitute must be compatible with standard SMD assembly processes and footprints.

Physical Envelope: Package dimensions and height constraints are critical for PCB layout compatibility. Substitutes must fit within or closely match the original footprint to avoid redesign requirements.

Operating Temperature Range: The GSX366 operates from −25°C to +85°C. Substitutes must support this range or a broader range to ensure reliability across all specified environmental conditions.

The JZ200 from Knowles Voltronics meets these substitution criteria with the following alignment: capacitance range 4.5–20pF (overlaps upper range), voltage rating 125V (exceeds requirement), top adjustment type, surface mount configuration, compact dimensions (4.50mm × 3.20mm), and operating temperature −40°C to +85°C (broader range).

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute: JZ200

The JZ200 is the active equivalent for the obsolete GSX366. Selection of the JZ200 is supported by the following engineering factors:

Product Status and Availability: The GSX366 is obsolete with no ongoing manufacturing. The JZ200 is active production with substantial inventory (141,516 pcs), ensuring long-term supply chain continuity.

Regulatory Compliance: The JZ200 carries RoHS Compliant and REACH Unaffected certifications, meeting modern environmental and regulatory standards required for commercial and industrial applications.

Electrical Performance: The JZ200 provides 125V rating (25V margin above GSX366), supporting the same 100V circuit requirement with additional safety margin. The capacitance range 4.5–20pF covers the upper operational band of the GSX366 (15–20pF), suitable for applications where minimum capacitance values below 4.5pF are not required.

Mechanical Compatibility: Both components feature top adjustment and surface mount configuration. The JZ200 package (4.50mm × 3.20mm, 1.45mm height) is smaller than the GSX366 (7.20mm × 5.40mm, 2.60mm height), providing layout flexibility and reduced PCB footprint.

Temperature Performance: The JZ200 operating range (−40°C to +85°C) exceeds the GSX366 specification (−25°C to +85°C), providing enhanced low-temperature performance.

Dielectric Consideration: The GSX366 uses PTFE dielectric while the JZ200 uses ceramic dielectric. This material difference affects frequency response and Q factor characteristics. The JZ200 Q factor of 1500 @ 1MHz indicates strong performance at lower frequencies, while the GSX366 Q factor of 1000 @ 10MHz indicates optimization for higher frequencies. Circuit-specific frequency requirements must be evaluated during substitution.

Frequently Asked Questions (FAQ)

Q: Can the JZ200 directly replace the GSX366 in all applications?

A: The JZ200 is functionally equivalent for applications requiring capacitance values between 4.5pF and 20pF. If the circuit requires capacitance values below 4.5pF, the JZ200 cannot provide the full adjustment range of the GSX366. Verify the specific tuning range required by your circuit design before substitution.

Q: What is the impact of dielectric material change from PTFE to ceramic?

A: PTFE and ceramic dielectrics exhibit different frequency response and temperature stability characteristics. PTFE (GSX366) provides superior high-frequency performance and lower dielectric loss at microwave frequencies. Ceramic (JZ200) offers higher Q factor at lower frequencies and better temperature stability. Select based on your circuit's operating frequency band and temperature coefficient requirements.

Q: Are there physical layout constraints when substituting GSX366 with JZ200?

A: The JZ200 is significantly smaller (4.50mm × 3.20mm vs. 7.20mm × 5.40mm) and lower profile (1.45mm vs. 2.60mm). This allows direct substitution with improved PCB space utilization. However, verify that the smaller footprint does not conflict with existing PCB routing or component placement constraints.

Q: Does the JZ200 meet environmental and regulatory requirements?

A: Yes. The JZ200 is RoHS Compliant and REACH Unaffected, meeting current environmental regulations. The GSX366 status for these certifications is not specified. If RoHS or REACH compliance is required for your application, the JZ200 is the appropriate choice.

Q: What is the voltage margin when using JZ200 instead of GSX366?

A: The JZ200 is rated at 125V compared to the GSX366 at 100V, providing a 25V safety margin. This additional margin supports circuit reliability and longevity under maximum voltage stress conditions.

Q: How does the Q factor difference affect circuit performance?

A: The GSX366 Q factor of 1000 @ 10MHz indicates optimization for high-frequency applications with lower insertion loss at microwave frequencies. The JZ200 Q factor of 1500 @ 1MHz indicates superior performance at lower frequencies. Evaluate your circuit's operating frequency to determine which Q factor characteristic is appropriate.

Q: Is the JZ200 available in the same packaging format as GSX366?

A: The JZ200 is supplied in Tape & Reel (TR) format, standard for high-volume SMD assembly. The GSX366 packaging format is not specified in available documentation. Verify packaging compatibility with your assembly process requirements.