HC-49/U-S4000000AHKB Equivalent & Substitute Parts

Part Overview

The HC-49/U-S4000000AHKB is a 4 MHz through-hole crystal oscillator manufactured by Citizen Finedevice Co Ltd. This component is actively produced and widely used in timing applications requiring fundamental mode operation with tight frequency tolerance. Substitute parts become necessary when the primary part experiences supply constraints, end-of-life transitions, or when design flexibility permits selection from multiple qualified sources meeting identical electrical and mechanical specifications.

Substiute Parts

HC-49/U-S4000000AHKB

Citizen Finedevice Co LtdIn Stock: 1164HC-49/U-S4000000AHKB Datasheet

Current PartRFQ

ECS-40-20-4DN

ECS Inc.In Stock: 1319ECS-40-20-4DN Datasheet

SimilarRFQ

ECS-40-20-4XDN

ECS Inc.In Stock: 10189ECS-40-20-4XDN Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for HC-49/U-S4000000AHKB is determined by strict equivalence across the following parameters: frequency (4 MHz), frequency tolerance (±30ppm), load capacitance (20pF), ESR (150 Ohms), operating mode (Fundamental), operating temperature range (-40°C to 85°C), mounting type (Through Hole), and package designation (HC-49/US).

The identified substitute parts ECS-40-20-4DN and ECS-40-20-4XDN satisfy all electrical and mechanical requirements. Both parts are manufactured by ECS Inc. and maintain identical frequency, tolerance, load capacitance, ESR, operating mode, temperature range, and package specifications. Dimensional variations within the HC-49/US package envelope do not affect functional compatibility.

Parameter Comparison

Engineering Selection Recommendations

For new designs and applications requiring RoHS3 compliance, ECS-40-20-4XDN is the appropriate substitute. This part maintains active product status, meets all electrical and mechanical specifications, and carries ROHS3 certification equivalent to the primary part.

ECS-40-20-4DN is electrically and mechanically equivalent but carries a "Not For New Designs" status and does not meet RoHS3 compliance requirements. This part is suitable only for legacy system maintenance or replacement scenarios where existing designs already incorporate this component.

HC-49/U-S4000000AHKB remains the primary selection for new applications where Citizen Finedevice sourcing is preferred or contractually specified.

Frequently Asked Questions (FAQ)

Q: Can ECS-40-20-4DN be used as a direct replacement for HC-49/U-S4000000AHKB in new designs?

A: ECS-40-20-4DN is electrically and mechanically equivalent but carries "Not For New Designs" status and lacks RoHS3 compliance. For new designs, ECS-40-20-4XDN is the appropriate ECS substitute.

Q: What are the dimensional differences between substitute parts?

A: HC-49/U-S4000000AHKB measures 0.453" L x 0.183" W (11.50mm x 4.66mm). Both ECS substitutes measure 0.447" L x 0.183" W (11.35mm x 4.65mm). Both remain within HC-49/US package specifications and are mechanically compatible.

Q: Are all three parts functionally interchangeable in the same circuit?

A: Yes. All three parts share identical frequency (4 MHz), frequency tolerance (±30ppm), load capacitance (20pF), ESR (150 Ohms), operating mode (Fundamental), temperature range (-40°C to 85°C), and package designation (HC-49/US). Functional interchangeability is confirmed.

Q: Which substitute should be selected for RoHS-compliant applications?

A: ECS-40-20-4XDN is ROHS3 compliant and maintains active product status. ECS-40-20-4DN is not RoHS compliant.

Q: What is the inventory status of each part?

A: HC-49/U-S4000000AHKB: 1126 pcs. ECS-40-20-4DN: 1297 pcs. ECS-40-20-4XDN: 10130 pcs.