FPXLF073-20 Equivalent & Substitute Parts

Part Overview

The FPXLF073-20 is a 7.3728 MHz crystal oscillator manufactured by Fox Electronics, designed for surface mount applications with 20pF load capacitance and 80 Ohms equivalent series resistance. This component operates in fundamental mode across the temperature range of -10°C to 70°C with ±50ppm frequency stability.

The FPXLF073-20 is classified as obsolete. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production requirements for systems utilizing this frequency standard.

Substiute Parts

FPXLF073-20

Fox ElectronicsIn Stock: 1169FPXLF073-20 Datasheet

Current PartRFQ

ECS-73-20-7SX-TR

ECS Inc.In Stock: 1188ECS-73-20-7SX-TR Datasheet

DirectRFQ

TT-SMDC-7.3728-20-EXT-TR

Raltron ElectronicsIn Stock: 1017TT-SMDC-7.3728-20-EXT-TR Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the FPXLF073-20 are qualified based on the following critical parameters:

• Frequency Match: 7.3728 MHz (exact)
• Load Capacitance: 20pF (exact)
• Operating Mode: Fundamental (exact)
• Mounting Type: Surface Mount (exact)
• Physical Dimensions: 12.50mm L x 4.60mm W, 3.70mm max height (exact)
• Frequency Stability: ±50ppm or better (equal or tighter tolerance acceptable)
• ESR: 80-100 Ohms (minor variation acceptable within crystal oscillator design margins)
• Operating Temperature Range: Must encompass or match -10°C to 70°C minimum
• Moisture Sensitivity Level: MSL 1 (Unlimited)

Two substitute parts meet these criteria:

Direct Substitute: ECS-73-20-7SX-TR (ECS Inc.) — Matches all critical parameters with tighter frequency tolerance (±30ppm).

Similar Substitute: TT-SMDC-7.3728-20-EXT-TR (Raltron Electronics) — Matches all critical parameters with extended operating temperature range (-40°C to 85°C) and active product status.

Parameter Comparison

Engineering Selection Recommendations

For Continued Support and New Applications: TT-SMDC-7.3728-20-EXT-TR (Raltron Electronics) is the preferred substitute. This part carries active product status, ensuring long-term availability and manufacturer support. It provides ROHS3 compliance and an extended operating temperature range (-40°C to 85°C), offering greater design flexibility for applications requiring wider thermal operation. The 100 Ohms ESR is within acceptable design margins for crystal oscillator circuits.

For Direct Parameter Matching with Tighter Tolerance: ECS-73-20-7SX-TR (ECS Inc.) provides a direct substitute with improved frequency tolerance (±30ppm versus ±50ppm), beneficial for applications requiring tighter frequency accuracy. However, this part is classified as "Not For New Designs," limiting its suitability for long-term production commitments.

Both substitute parts maintain identical physical dimensions, load capacitance, and fundamental operating mode, ensuring mechanical and electrical compatibility within standard crystal oscillator circuit designs.

Frequently Asked Questions (FAQ)

Q: Can ECS-73-20-7SX-TR and TT-SMDC-7.3728-20-EXT-TR be used interchangeably with FPXLF073-20?

A: Both parts meet the critical substitution criteria: identical frequency (7.3728 MHz), load capacitance (20pF), physical dimensions, and operating mode. The 20 Ohm difference in ESR (80 Ohms vs. 100 Ohms) falls within acceptable design tolerances for crystal oscillator circuits. Mechanical compatibility is confirmed through matching package dimensions and MSL ratings.

Q: What is the significance of the ESR difference between FPXLF073-20 (80 Ohms) and the substitute parts (100 Ohms)?

A: ESR variation of ±20 Ohms is within standard design margins for crystal oscillator applications. The circuit's load capacitance and frequency stability remain unaffected by this minor ESR difference. Verification through circuit simulation or prototype testing is appropriate for applications with stringent phase noise or startup time requirements.

Q: Why is TT-SMDC-7.3728-20-EXT-TR recommended over ECS-73-20-7SX-TR?

A: TT-SMDC-7.3728-20-EXT-TR carries active product status, ensuring ongoing manufacturer support and supply chain availability. ECS-73-20-7SX-TR is designated "Not For New Designs," indicating limited future availability and potential discontinuation. For production applications requiring long-term component sourcing, the active status of the Raltron part provides superior supply chain security.

Q: Are there package compatibility considerations between 4-SMD and 4-SOJ configurations?

A: Both package types are surface mount configurations with identical external dimensions (12.50mm x 4.60mm x 3.70mm max height). The primary difference is internal lead configuration (SMD vs. SOJ). PCB footprints designed for one configuration may require minor adjustment for the other. Consult component datasheets and PCB layout guidelines to confirm footprint compatibility before implementation.

Q: What compliance certifications apply to these substitute parts?

A: Both ECS-73-20-7SX-TR and TT-SMDC-7.3728-20-EXT-TR are ROHS3 compliant and REACH unaffected. All three parts (including the original FPXLF073-20) carry ECCN EAR99 classification and HTSUS code 8541.60.0050. MSL rating of 1 (Unlimited) applies to all parts, indicating no moisture sensitivity restrictions during storage or handling.