ECS-73-20-7S-TR Equivalent & Substitute Parts

Part Overview

The ECS-73-20-7S-TR is a 7.3728 MHz crystal oscillator in 4-SOJ surface mount package with 20pF load capacitance and 80 Ohms equivalent series resistance. This component is classified as Not For New Designs, indicating it has reached end-of-life status. Identifying equivalent substitute parts is necessary for legacy system maintenance, repair operations, and continued production support where this frequency and load capacitance specification remains required.

Substiute Parts

ECS-73-20-7S-TR

ECS Inc.In Stock: 2184ECS-73-20-7S-TR Datasheet

Current PartRFQ

ECS-73-18-7SX-TR

ECS Inc.In Stock: 10591ECS-73-18-7SX-TR Datasheet

SimilarRFQ

ECS-73-20-7SX-TR

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

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the ECS-73-20-7S-TR is determined by the following critical parameters:

Mandatory Match Parameters:

• Frequency: 7.3728 MHz (exact match required)
• Frequency Tolerance: ±30ppm (exact match required)
• Load Capacitance: 20pF (exact match required)
• Package / Case: 4-SOJ, 9.40mm pitch (exact match required)
• Mounting Type: Surface Mount (exact match required)
• Operating Temperature Range: -10°C ~ 70°C (exact match required)

Allowable Variation Parameters:

• ESR (Equivalent Series Resistance): 80 Ohms to 100 Ohms (within acceptable tolerance for circuit operation)
• Series Designation: ECX-3S or ECX-3SX (different internal series, same external specifications)

Two substitute parts meet these criteria: ECS-73-20-7SX-TR and ECS-73-18-7SX-TR. The ECS-73-20-7SX-TR maintains identical load capacitance (20pF) with ESR variation. The ECS-73-18-7SX-TR differs in load capacitance (18pF vs. 20pF) and represents a secondary substitute option.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute: ECS-73-20-7SX-TR

The ECS-73-20-7SX-TR is the direct functional equivalent of the ECS-73-20-7S-TR. Both parts maintain identical frequency (7.3728 MHz), frequency tolerance (±30ppm), and load capacitance (20pF). The ESR difference (100 Ohms vs. 80 Ohms) falls within acceptable operating margins for crystal oscillator circuits. The ECS-73-20-7SX-TR provides ROHS3 compliance, whereas the original part is RoHS non-compliant. This substitute is suitable for direct replacement in legacy system repairs and maintenance applications.

Secondary Substitute: ECS-73-18-7SX-TR

The ECS-73-18-7SX-TR shares the same frequency and frequency tolerance but operates with 18pF load capacitance instead of 20pF. This load capacitance difference requires circuit-level evaluation to confirm compatibility with the oscillator circuit design. The ECS-73-18-7SX-TR is applicable only when the receiving circuit can accommodate the 18pF load capacitance specification. This part also provides ROHS3 compliance.

Selection between primary and secondary substitutes depends on circuit load capacitance requirements and component availability.

Frequently Asked Questions (FAQ)

Q: Can ECS-73-20-7SX-TR replace ECS-73-20-7S-TR directly without circuit modification?

A: Yes. Both parts operate at 7.3728 MHz with ±30ppm tolerance and 20pF load capacitance. The ESR increase from 80 Ohms to 100 Ohms is within acceptable operating parameters for standard crystal oscillator circuits. No circuit modification is required.

Q: What is the significance of the load capacitance difference between the 20pF and 18pF variants?

A: Load capacitance determines the frequency at which the crystal oscillates in a given circuit. The 20pF load capacitance is calibrated for circuits designed with 20pF load specifications. The 18pF variant is calibrated for different circuit impedance conditions. Substituting 18pF for 20pF without circuit verification may result in frequency deviation outside tolerance specifications.

Q: Are all three parts mechanically interchangeable?

A: Yes. All three parts use the 4-SOJ package with 9.40mm pitch, identical dimensions (12.50mm x 4.60mm), and identical maximum seated height (3.70mm). Mechanical and PCB footprint compatibility is confirmed across all variants.

Q: What is the difference between the ECX-3S and ECX-3SX series designations?

A: The series designation indicates internal design revision. The ECX-3S (original part) and ECX-3SX (substitute parts) represent different manufacturing generations from ECS Inc. External electrical and mechanical specifications remain equivalent within the parameters specified.

Q: Does RoHS compliance affect substitution eligibility?

A: RoHS compliance status does not affect electrical or mechanical substitution eligibility. The ECS-73-20-7S-TR is RoHS non-compliant, while both substitute parts are ROHS3 compliant. For applications subject to RoHS regulatory requirements, the ROHS3 compliant substitutes provide regulatory alignment.

Q: What is the Moisture Sensitivity Level (MSL) rating, and is it consistent across all parts?

A: MSL 1 (Unlimited) indicates the component has unlimited shelf life and requires no special moisture control during storage or handling. All three parts share this MSL rating, confirming consistent handling and storage requirements.