ECS-120-S-4 Crystal Equivalent & Substitute Parts

Part Overview

The ECS-120-S-4 is a 12 MHz through-hole crystal oscillator in HC-49/US package configuration, designed for fundamental mode operation with 60 Ohms equivalent series resistance. This part carries a "Not For New Designs" status, indicating it has been superseded in the manufacturer's product line. Identifying equivalent substitute parts is necessary for ongoing production support, legacy system maintenance, and design continuity where this frequency and package specification is required.

Substiute Parts

ECS-120-S-4

ECS Inc.In Stock: 1074ECS-120-S-4 Datasheet

Current PartRFQ

ECS-120-S-4X

ECS Inc.In Stock: 2118ECS-120-S-4X Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the ECS-120-S-4 is determined by strict equivalence across the following critical parameters:

• Frequency: 12 MHz (exact match required)
• Frequency Tolerance: ±30ppm (exact match required)
• Frequency Stability: ±50ppm (exact match required)
• ESR: 60 Ohms (exact match required)
• Operating Mode: Fundamental (exact match required)
• Package / Case: HC-49/US (exact match required)
• Mounting Type: Through Hole (exact match required)
• Operating Temperature Range: -10°C ~ 70°C (exact match required)
• Load Capacitance: Series (exact match required)
• Physical Dimensions: 0.447" L x 0.183" W, Height 0.138" max (exact match required)

The ECS-120-S-4X meets all these criteria and qualifies as a parametric equivalent substitute.

Parameter Comparison

Engineering Selection Recommendations

The ECS-120-S-4X is the direct parametric equivalent for the ECS-120-S-4. All electrical and mechanical specifications are identical. The primary distinction is product lifecycle status: the ECS-120-S-4 is designated "Not For New Designs," while the ECS-120-S-4X carries "Active" status, indicating ongoing manufacturer support and availability.

The ECS-120-S-4X also provides improved regulatory compliance, meeting ROHS3 requirements compared to the non-compliant status of the original part. Both parts maintain identical MSL, REACH, ECCN, and HTSUS classifications.

For applications requiring the 12 MHz HC-49/US through-hole crystal with 60 Ohms ESR and ±30ppm tolerance, the ECS-120-S-4X is the appropriate selection for current production and ongoing support.

Frequently Asked Questions (FAQ)

Q: Can the ECS-120-S-4X be used as a direct replacement for the ECS-120-S-4?

A: Yes. The ECS-120-S-4X is a parametric equivalent with identical frequency, tolerance, stability, ESR, package, mounting type, temperature range, and physical dimensions. No circuit modifications are required.

Q: What is the difference between the ECS-120-S-4 and ECS-120-S-4X?

A: The parts are electrically and mechanically identical. The ECS-120-S-4X is the active production version with ROHS3 compliance, while the ECS-120-S-4 is obsolete and non-compliant. The series designation differs slightly (HC-49US vs. HC-49USX).

Q: Are there any compatibility concerns with PCB footprints?

A: No. Both parts use the HC-49/US package with identical dimensions (0.447" L x 0.183" W, 0.138" max height). PCB footprints and through-hole spacing are fully compatible.

Q: Does the ECS-120-S-4X meet current regulatory requirements?

A: Yes. The ECS-120-S-4X is ROHS3 compliant and REACH unaffected, meeting current regulatory standards. The original ECS-120-S-4 is RoHS non-compliant.

Q: What is the inventory status of these parts?

A: The ECS-120-S-4 has 1043 pieces in stock. The ECS-120-S-4X has 2083 pieces in stock, providing greater availability for ongoing production needs.