ECS-90-S-4 9 MHz Crystal Equivalent & Substitute Parts

Part Overview

The ECS-90-S-4 is a 9 MHz through-hole crystal oscillator in HC-49/US package designed for fundamental mode operation. This component is classified as "Not For New Designs," indicating it has reached end-of-life status. For new applications or ongoing production requiring 9 MHz crystal functionality with identical electrical and mechanical specifications, equivalent substitute parts are available from the same manufacturer with active product status and improved compliance certifications.

Substiute Parts

ECS-90-S-4

ECS Inc.In Stock: 1019ECS-90-S-4 Datasheet

Current PartRFQ

ECS-90-S-4X

ECS Inc.In Stock: 1370ECS-90-S-4X Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the ECS-90-S-4 is determined by strict equivalence across the following critical parameters:

• Frequency: 9 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)
• Operating Temperature Range: -10°C ~ 70°C (exact match required)
• Package / Case: HC-49/US (exact match required)
• Mounting Type: Through Hole (exact match required)
• Physical Dimensions: 0.447" L x 0.183" W, Height 0.138" max (exact match required)

The ECS-90-S-4X meets all these criteria and is therefore a direct parametric equivalent. The primary distinction between the main part and its substitute is product lifecycle status and compliance certification level.

Parameter Comparison

Engineering Selection Recommendations

The ECS-90-S-4X is the direct substitute for the ECS-90-S-4. Selection between these parts should be based on the following factors:

For new designs and ongoing production: The ECS-90-S-4X is the appropriate choice. It maintains identical electrical and mechanical specifications while offering Active product status and ROHS3 compliance certification. This ensures long-term component availability and regulatory alignment.

For legacy system maintenance: The ECS-90-S-4 may be retained if existing inventory is available and regulatory requirements do not mandate RoHS compliance. However, the ECS-90-S-4X provides a direct replacement path with no design modifications required.

Both parts are manufactured by ECS Inc., share the same HC-49/US package footprint, and are functionally interchangeable at the circuit level.

Frequently Asked Questions (FAQ)

Q: Can the ECS-90-S-4X be used as a direct replacement for the ECS-90-S-4 without circuit modifications?

A: Yes. The ECS-90-S-4X is a parametric equivalent with identical frequency, tolerance, stability, ESR, operating temperature range, and physical dimensions. No circuit modifications are required for substitution.

Q: What is the primary reason to transition from ECS-90-S-4 to ECS-90-S-4X?

A: The ECS-90-S-4 is classified as "Not For New Designs," indicating end-of-life status. The ECS-90-S-4X is an Active product with ROHS3 compliance, ensuring continued availability and regulatory compliance for new and ongoing production.

Q: Are the physical dimensions and mounting footprints identical?

A: Yes. Both parts use the HC-49/US package with dimensions of 0.447" L x 0.183" W (11.35mm x 4.65mm) and maximum seated height of 0.138" (4.60mm). They are mechanically interchangeable on PCBs designed for HC-49/US through-hole crystals.

Q: What is the difference in RoHS compliance between these parts?

A: The ECS-90-S-4 is RoHS non-compliant, while the ECS-90-S-4X is ROHS3 compliant. For applications subject to RoHS regulations or customer requirements, the ECS-90-S-4X is the required choice.

Q: Are there any electrical performance differences between the two parts?

A: No. Both parts specify identical frequency (9 MHz), frequency tolerance (±30ppm), frequency stability (±50ppm), ESR (60 Ohms), operating mode (Fundamental), and operating temperature range (-10°C ~ 70°C).